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Amateurfunk-Anki/explanations.json
T
imple a47795b081 Add explanations for E* questions 
Automatically generated using Codex and GPT 5.5 in high reasoning mode
and Claude Code with Opus 4.7 in high reasoning mode, models cross
checking each other
2026-05-23 00:07:59 +02:00

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{
"BA101": {
"revision": 2,
"explanation": "DD4UQ spells D as Delta, U as Uniform and Q as Quebec; the traps are country-style words such as Denmark, Uruguay and Queen, which are not the ITU code words.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA102": {
"revision": 2,
"explanation": "DK1KC uses Delta for D, Kilo for K and Charlie for C; Kilowatt, Denmark and Caesar are distractors, not ITU spelling-alphabet words.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA103": {
"revision": 2,
"explanation": "DK5WP maps to Delta Kilo 5 Whiskey Papa; Kilowatt, William and Paris are common-looking substitutes but not the ITU words for K, W and P.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA104": {
"revision": 2,
"explanation": "DL1FLO maps D/L/F/L/O to Delta, Lima, Foxtrot, Lima, Oscar; London, Florida and Oslo are distractors rather than ITU code words.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA105": {
"revision": 2,
"explanation": "DL4YBZ uses Yankee, Bravo and Zulu for Y, B and Z; Ypsilon, Baker and Zebra are the non-ITU traps in the answer choices.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA106": {
"revision": 2,
"explanation": "DM4EAX spells M as Mike, E as Echo, A as Alfa and X as X-ray; Madagascar, Ecuador and Amerika are distractors outside the ITU alphabet.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA107": {
"revision": 2,
"explanation": "DN9RO/p uses Romeo and Oscar for R and O, while '/' is spoken as Stroke before the portable suffix; Radio, Oslo and Nordpol are distractors.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA108": {
"revision": 2,
"explanation": "DN9STV maps S/T/V to Sierra, Tango and Victor; Santiago, Texas and Vulcano are plausible-sounding but not ITU code words.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA109": {
"revision": 2,
"explanation": "DO9XJZ uses X-ray, Juliett and Zulu for X, J and Z; Xavier, Japan and Zebra are the distractor words.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BA110": {
"revision": 2,
"explanation": "IG9/DL4HR starts India Golf and uses Stroke for '/', with Hotel and Romeo at the end; Italy, Guatemala and Honolulu are distractors.",
"source": "https://life.itu.int/radioclub/rr/ap14.pdf",
"confidence": 9
},
"BB101": {
"revision": 1,
"explanation": "Abbreviations and Q groups compress common operating messages, so slow text modes carry more meaning per character and keep contacts concise.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB102": {
"revision": 1,
"explanation": "CQ is the standard open invitation to any station, not a call to one named station.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB103": {
"revision": 1,
"explanation": "DX is operating shorthand for a distant station or long-distance contact; the distance threshold depends on band and propagation.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB104": {
"revision": 1,
"explanation": "On VHF/UHF, normal local coverage is limited, so DX means stations well beyond local range, typically more than a few hundred kilometres away.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB105": {
"revision": 1,
"explanation": "On 80 m at night, intercontinental propagation is plausible, so 'CQ DX' asks for stations from other continents rather than nearby stations.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB106": {
"revision": 1,
"explanation": "TX, RX, and TRX follow the transmit/receive naming convention: transmitter, receiver, and a combined transceiver.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB107": {
"revision": 1,
"explanation": "CW names the continuous carrier used for Morse telegraphy; the information is keyed by interrupting or shifting that carrier.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB108": {
"revision": 1,
"explanation": "BK is the telegraphy break signal: it interrupts the current transmission or hands over informally without the full closing sequence.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB109": {
"revision": 1,
"explanation": "K is the procedural invitation to transmit, so it marks that the other station may answer.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB110": {
"revision": 1,
"explanation": "R at the start of a telegraphy over means 'received', confirming that the previous transmission was copied.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB201": {
"revision": 1,
"explanation": "These Q groups encode common reception conditions: QRM is man-made interference, QRN is atmospheric noise, and QSB asks about fading.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB202": {
"revision": 1,
"explanation": "With a question mark, QRO asks about increasing power, QSO asks about direct communication, and QRX asks when the next call should happen.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB203": {
"revision": 1,
"explanation": "QRT orders stopping transmission, QRZ asks who is calling, and QSL? asks whether reception can be confirmed.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB204": {
"revision": 1,
"explanation": "QRV states readiness, QRM? asks whether interference is present, and QTH gives a station location.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB205": {
"revision": 1,
"explanation": "QRP is the operating signal for reducing transmitter power, so 'PSE QRP' is a polite request to turn it down.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BB206": {
"revision": 1,
"explanation": "QSY is the operating signal for changing frequency, so 'PSE QSY' asks you to move to another frequency.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BC101": {
"revision": 1,
"explanation": "The 10 m amateur band is around 28 MHz, which lies in the 3-30 MHz HF shortwave range.",
"source": "ITU Radio Regulations, Article 2",
"confidence": 9
},
"BC102": {
"revision": 1,
"explanation": "The 2 m band is around 144-146 MHz, which lies in the 30-300 MHz VHF range.",
"source": "ITU Radio Regulations, Article 2",
"confidence": 9
},
"BC103": {
"revision": 1,
"explanation": "The 70 cm band is around 430-440 MHz, which lies in the 300-3000 MHz UHF range.",
"source": "ITU Radio Regulations, Article 2",
"confidence": 9
},
"BC104": {
"revision": 1,
"explanation": "HF is defined as 3-30 MHz; those wavelengths are roughly 100 m to 10 m, hence shortwave/KW.",
"source": "ITU Radio Regulations, Article 2",
"confidence": 9
},
"BC105": {
"revision": 1,
"explanation": "VHF is defined as 30-300 MHz; in German amateur practice this is the UKW range.",
"source": "ITU Radio Regulations, Article 2",
"confidence": 9
},
"BC106": {
"revision": 1,
"explanation": "UHF is defined as 300-3000 MHz; its wavelengths are in the decimetre range.",
"source": "ITU Radio Regulations, Article 2",
"confidence": 9
},
"BC201": {
"revision": 1,
"explanation": "IARU band plans are coordination recommendations, not law, but following them prevents incompatible modes from crowding each other.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2021/06/hf_r1_bandplan.pdf",
"confidence": 7
},
"BC202": {
"revision": 1,
"explanation": "The HF band-plan convention uses lower sideband below 10 MHz, so 80 m normally uses LSB.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2021/06/hf_r1_bandplan.pdf",
"confidence": 7
},
"BC203": {
"revision": 1,
"explanation": "The HF band-plan convention uses upper sideband above 10 MHz, so 20 m normally uses USB.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2021/06/hf_r1_bandplan.pdf",
"confidence": 7
},
"BC204": {
"revision": 1,
"explanation": "Band plans put narrow Morse activity at the lower edge of most bands, leaving wider modes farther up the band.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2021/06/hf_r1_bandplan.pdf",
"confidence": 7
},
"BC205": {
"revision": 1,
"explanation": "The Region 1 VHF plan marks 145.500 MHz as the 2 m FM calling frequency, so it is used for general FM calls.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC206": {
"revision": 1,
"explanation": "The Region 1 UHF plan marks 433.500 MHz as the 70 cm FM calling frequency, so it is used for general FM calls.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC207": {
"revision": 1,
"explanation": "The 2 m band plan lists 145.375 MHz for digital voice calling, separating it from analogue FM calling traffic.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC208": {
"revision": 1,
"explanation": "The 70 cm band plan lists 433.450 MHz for digital voice calling, separating it from analogue FM calling traffic.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC209": {
"revision": 1,
"explanation": "145.450 MHz falls in the 2 m FM simplex channel area, so it is suitable for an FM voice contact under the band plan.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC210": {
"revision": 1,
"explanation": "144.310 MHz sits near the 144.300 MHz SSB centre of activity, so it is appropriate for 2 m SSB voice.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC211": {
"revision": 1,
"explanation": "The 2 m band plan uses 144.300 MHz as the SSB centre of activity.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC212": {
"revision": 1,
"explanation": "The 70 cm band plan uses 432.200 MHz as the SSB centre of activity.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC213": {
"revision": 1,
"explanation": "144.075 MHz lies in the narrow Morse-preferred segment, so wider or keyboard digital modes should use their own segments.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC214": {
"revision": 1,
"explanation": "Around 144.125 MHz the 2 m band plan is for Morse and narrow digital work, not local FM voice.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC215": {
"revision": 1,
"explanation": "Around 144.450 MHz the 2 m band plan reserves beacon use, so an ordinary local FM QSO would occupy the wrong segment.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC216": {
"revision": 1,
"explanation": "The 145.500-145.5625 MHz FM simplex area is channelised for narrow FM, so keeping to about 12 kHz avoids adjacent-channel interference.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC217": {
"revision": 1,
"explanation": "145.600 MHz is in the 2 m repeater output area, so a direct local FM contact would interfere with repeater operation.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC218": {
"revision": 1,
"explanation": "145.800 MHz belongs to the 2 m space-communication segment, so it should be kept clear for satellite and other space contacts.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC219": {
"revision": 1,
"explanation": "432.040 MHz lies in the 70 cm Morse/narrow digital segment, so local FM voice would be the wrong bandwidth and mode there.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC220": {
"revision": 1,
"explanation": "432.450 MHz is assigned to beacon activity in the 70 cm plan, so it should not be used for an ordinary local FM contact.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC221": {
"revision": 1,
"explanation": "435.500 MHz lies in the 70 cm satellite segment, so terrestrial local FM would risk interfering with satellite operation.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BC222": {
"revision": 1,
"explanation": "439.200 MHz is in the 70 cm repeater output area, so a direct local FM contact would occupy repeater spectrum.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BD101": {
"revision": 1,
"explanation": "German club-station call signs use zero in the numeral position; DA0ABC therefore identifies a club station.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 9
},
"BD102": {
"revision": 1,
"explanation": "AFuV §16 allows BNetzA to permit special experimental or technical-scientific studies and to make that dependent on assigning another call sign.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"BD103": {
"revision": 1,
"explanation": "DL0 is in the German club-station pattern for class A, and the zero distinguishes it from person-bound DL1-DL9 calls.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 9
},
"BD104": {
"revision": 1,
"explanation": "In the German call-sign plan, DL1-DL9 with normal two- or three-letter suffixes are person-bound class A call signs.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 9
},
"BD105": {
"revision": 1,
"explanation": "The German call-sign plan assigns DN9 to person-bound class N call signs.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 9
},
"BD106": {
"revision": 1,
"explanation": "The German call-sign plan assigns DO1-DO9 with normal suffixes to person-bound class E call signs.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 9
},
"BD107": {
"revision": 1,
"explanation": "DP0GVN is one of the German exterritorial class A station patterns; DP0 is used for special locations outside ordinary German territory.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BD108": {
"revision": 1,
"explanation": "DP0POL follows the same exterritorial class A pattern as other German Antarctic or special-location stations.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BD109": {
"revision": 1,
"explanation": "Low-power transmitters for direction finding may identify with short MO-series markers instead of a normal amateur call sign.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 9
},
"BD201": {
"revision": 1,
"explanation": "The suffix /am means aeronautical mobile: the station is operating from an aircraft.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BD202": {
"revision": 1,
"explanation": "VE is a Canadian call-sign series, and /am adds that the station is being operated from an aircraft.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD203": {
"revision": 1,
"explanation": "The suffix /m means mobile; for amateur operation that includes a station moving in a land vehicle.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BD204": {
"revision": 1,
"explanation": "The suffix /m can also mark mobile operation on inland waterways, distinct from /mm on the high seas.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BD205": {
"revision": 1,
"explanation": "The suffix /mm means maritime mobile, so the station is aboard a vessel at sea rather than on land or inland water.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BD206": {
"revision": 1,
"explanation": "The suffix /p is used as extra information for portable or temporarily fixed operation.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 9
},
"BD207": {
"revision": 1,
"explanation": "AFuV allows internationally customary suffixes but does not require /p for portable or temporary fixed operation in Germany.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 9
},
"BD208": {
"revision": 1,
"explanation": "AFuV §11 names Remote for speech and /R for telegraphy or digital modes when marking remote operation.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 10
},
"BD209": {
"revision": 1,
"explanation": "For training operation, AFuV §11 requires /Trainee in speech, so the trainee uses the instructor's call sign plus that suffix.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 10
},
"BD210": {
"revision": 1,
"explanation": "Training operation may use the club-station call sign, but AFuV §11 requires the training suffix /Trainee for speech or /T for telegraphy/digital modes.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 10
},
"BD211": {
"revision": 1,
"explanation": "For training in Morse or digital modes, AFuV §11 requires the short /T suffix on the instructor's call sign.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 10
},
"BD212": {
"revision": 1,
"explanation": "CEPT guest operation uses the visited country's prefix before the home call sign, so a UK G3MM station temporarily in Germany signs with DL/.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 9
},
"BD213": {
"revision": 1,
"explanation": "CEPT Novice guest operation in Switzerland uses the Swiss novice visitor prefix HB3 before the German class E call sign.",
"source": "https://docdb.cept.org/download/2768",
"confidence": 9
},
"BD214": {
"revision": 1,
"explanation": "CEPT guest operation in Switzerland uses the Swiss HB9 prefix before the German class A call sign.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 9
},
"BD301": {
"revision": 1,
"explanation": "Unknown prefixes are a lookup item: the ITU call-sign allocation table, handbooks, and callbooks map prefix blocks to countries.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD302": {
"revision": 1,
"explanation": "ITU call-sign series split DA-DR to Germany, DS-DT to South Korea, and DU-DZ to the Philippines.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD303": {
"revision": 1,
"explanation": "The ITU prefix table maps OE to Austria, ON to Belgium, and OK to Czechia.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD304": {
"revision": 1,
"explanation": "The ITU prefix table maps OE to Austria, PA to the Netherlands, and SM to Sweden.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD305": {
"revision": 1,
"explanation": "The ITU prefix table maps F to France, PA to the Netherlands, and SP to Poland.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD306": {
"revision": 1,
"explanation": "The ITU prefix table maps SM to Sweden, SP to Poland, and ZS to South Africa.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD307": {
"revision": 1,
"explanation": "The ITU prefix table maps 4X to Israel, F to France, and OZ to Denmark.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD308": {
"revision": 1,
"explanation": "The ITU prefix table maps EA to Spain, EI to Ireland, EK to Armenia, EM to Ukraine, and ES to Estonia.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD309": {
"revision": 1,
"explanation": "The ITU prefix table maps VE to Canada, VK to Australia, and PY to Brazil.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD310": {
"revision": 1,
"explanation": "The ITU prefix table maps HB9 to Switzerland, EA to Spain, and ON to Belgium.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD311": {
"revision": 1,
"explanation": "The ITU prefix table maps EA to Spain, LX to Luxembourg, and SP to Poland.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD312": {
"revision": 1,
"explanation": "The ITU prefix table maps W to the United States, ZL to New Zealand, and LU to Argentina.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD313": {
"revision": 1,
"explanation": "The ITU prefix table maps BY to China, VE to Canada, and VK to Australia.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD314": {
"revision": 1,
"explanation": "F, HB9, OZ, and SP correspond to France, Switzerland, Denmark, and Poland, all neighbours of Germany.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD315": {
"revision": 1,
"explanation": "K and W are United States call-sign series, so K3LR, W3DZZ, and K4EAX are all US-style calls.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD316": {
"revision": 1,
"explanation": "W, VE, and XE identify the United States, Canada, and Mexico; all three are on North America.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD317": {
"revision": 1,
"explanation": "PY, CE, and LU identify Brazil, Chile, and Argentina, all in South America.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BD318": {
"revision": 1,
"explanation": "BY, JA, and VU identify China, Japan, and India, all in Asia.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"BE101": {
"revision": 1,
"explanation": "A contact starts either as a general call, a directed call, or an answer to a call; in every case the own call sign identifies the transmitting station.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 9
},
"BE102": {
"revision": 1,
"explanation": "Answering CQ first names the station being called, then gives your own call sign once, which makes both sides of the intended contact clear.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE103": {
"revision": 1,
"explanation": "A partial call containing your suffix is not enough certainty, so asking whether you were called avoids answering for another station.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE104": {
"revision": 1,
"explanation": "In English phone procedure, name the station you are calling first and then identify yourself with 'this is' plus your call sign.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE105": {
"revision": 1,
"explanation": "A clear frequency may still be in use, so asking whether it is occupied before calling CQ reduces accidental interference.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE106": {
"revision": 1,
"explanation": "On higher HF bands, skip propagation can create a dead zone: you may not hear a nearby station that is nevertheless using the frequency.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE107": {
"revision": 1,
"explanation": "145.500 MHz is a calling channel; after contact is made, moving by QSY keeps the calling channel available for others.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BE108": {
"revision": 1,
"explanation": "After your CQ contact ends, the original frequency should not become a queue; arranging QSY keeps the calling or working frequency usable.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE109": {
"revision": 1,
"explanation": "On 2 m and 70 cm, 'DX' means well beyond normal local range, so local or nearby stations should wait.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE110": {
"revision": 1,
"explanation": "CQ VK/ZL is a directed CQ for Australia and New Zealand prefixes, so a non-VK/ZL station should not answer.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE111": {
"revision": 1,
"explanation": "The Maidenhead locator encodes geographic position into grid fields and squares, giving a compact location reference for radio contacts.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE112": {
"revision": 1,
"explanation": "A CW CQ repeats CQ and the own call sign, uses DE for 'from', and ends with K to invite replies.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE113": {
"revision": 1,
"explanation": "CQ DL is a directed general call for German stations, and PSE K politely invites those stations to answer.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE114": {
"revision": 1,
"explanation": "CQ DX on 20 m asks for distant intercontinental contacts; a European station should not answer a Swiss station's DX call.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE115": {
"revision": 1,
"explanation": "QRZ? asks 'who is calling me?' and in a pile-up it is also used to invite the next callers.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE116": {
"revision": 1,
"explanation": "CQ FD and TEST mark contest traffic for Field Day, and /P says the station is operating portable.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE117": {
"revision": 1,
"explanation": "Matching or slowing down to the caller's Morse speed improves copy and avoids forcing the other operator beyond their receive speed.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE118": {
"revision": 1,
"explanation": "Morse should be sent no faster than you can copy and adjusted to slower stations, because reliable exchange matters more than speed.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE201": {
"revision": 1,
"explanation": "RST is a compact reception report, so it summarizes how well the signal can be read and, where relevant, its strength and tone.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE202": {
"revision": 1,
"explanation": "The letters name the three report dimensions: Readability, Strength, and Tone.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE203": {
"revision": 1,
"explanation": "The RST scale uses R 1-5 for readability, S 1-9 for signal strength, and T 1-9 for tone quality.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE204": {
"revision": 2,
"explanation": "On the analogue S-meter, the needle indicates S5. For SSB phone the tone digit is omitted; clear copy gives R5, so the report is 55.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE205": {
"revision": 2,
"explanation": "On the analogue S-meter, the needle indicates S9. For SSB phone the tone digit is omitted; clear copy gives R5, so the report is 59.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE206": {
"revision": 2,
"explanation": "On the analogue S-meter, the needle is 20 dB over S9. For SSB phone the tone digit is omitted, so clear copy is reported as 59+20 dB.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE207": {
"revision": 2,
"explanation": "On the digital display, the shown signal level is S5. For SSB phone the tone digit is omitted; clear copy gives R5, so the report is 55.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE208": {
"revision": 2,
"explanation": "On the digital display, the shown signal level is S9. For SSB phone the tone digit is omitted; clear copy gives R5, so the report is 59.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE209": {
"revision": 2,
"explanation": "On the digital display, the shown signal level is 20 dB over S9. For SSB phone the tone digit is omitted, so clear copy is reported as 59+20 dB.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE210": {
"revision": 1,
"explanation": "SSTV sends pictures, so the practical way to report image quality is to include the report text in the transmitted image itself.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE301": {
"revision": 1,
"explanation": "Contests are structured operating exercises: competition pressure improves station setup, operator skill, and operating technique.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__2.html",
"confidence": 9
},
"BE302": {
"revision": 1,
"explanation": "Contest scoring rewards many valid contacts in limited time, so exchanges are deliberately short and standardized.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE303": {
"revision": 1,
"explanation": "A contest QSO counts only if both stations exchange the data required by that contest's rules.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE304": {
"revision": 1,
"explanation": "In a Sprint contest, handing over the frequency after each QSO prevents one station from holding the run frequency continuously.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE305": {
"revision": 1,
"explanation": "A pile-up is what happens when many stations call the same desirable station at once.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE306": {
"revision": 1,
"explanation": "'Only number 3' filters a pile-up by the numeral in the call sign, so only calls with 3 between prefix and suffix should call.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE307": {
"revision": 1,
"explanation": "List operation uses a strong control station to collect callers and call them in order, reducing chaos around a rare station.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE308": {
"revision": 1,
"explanation": "Split operation separates transmit and receive frequencies, letting a rare station listen where callers transmit while keeping its own transmit frequency clear.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE309": {
"revision": 1,
"explanation": "'Split up 14270 to 14280' means the station transmits on its announced frequency but listens for callers across that higher range.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE310": {
"revision": 1,
"explanation": "'5 up' means the wanted station listens 5 kHz above its transmit frequency, so callers must transmit there and listen on the station's frequency.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE311": {
"revision": 1,
"explanation": "'Tuning 290 to 300 up' gives the listening window by shorthand: transmit between 14290 and 14300 kHz while listening to 14205 kHz.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE312": {
"revision": 1,
"explanation": "A DX-pedition deliberately activates a rare country or island so other amateurs can work a location that is normally hard to hear.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE313": {
"revision": 1,
"explanation": "ARDF is a direction-finding contest: operators use portable receivers to locate hidden low-power transmitters that transmit briefly.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE401": {
"revision": 1,
"explanation": "A repeater is duplex: users transmit to its input, and the repeater retransmits what it hears on its output.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE402": {
"revision": 1,
"explanation": "German 2 m repeaters conventionally use a -600 kHz shift, so the input is 600 kHz below the output.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BE403": {
"revision": 1,
"explanation": "German 70 cm repeaters conventionally use a -7.6 MHz shift, so the input is 7.6 MHz below the output.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2024/11/VHF_Handbook_V10_02.pdf",
"confidence": 7
},
"BE404": {
"revision": 1,
"explanation": "A short pause before each over leaves a gap for another station to break in without doubling.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE405": {
"revision": 1,
"explanation": "Clear handover tells everyone whose turn it is, which prevents two stations from transmitting at the same time.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE406": {
"revision": 1,
"explanation": "Repeaters are shared resources, and short overs leave access opportunities for mobile and portable users with changing signal conditions.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE407": {
"revision": 1,
"explanation": "Wide FM spills into adjacent repeater inputs and can overdrive a narrow repeater receiver, causing interference or distorted retransmission.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE408": {
"revision": 1,
"explanation": "Over a repeater, your S-meter reads the repeater's downlink, not the other user's uplink, so only readability describes the other user's signal.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE409": {
"revision": 1,
"explanation": "Beacons provide known reference signals; hearing or not hearing them indicates current propagation conditions.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE410": {
"revision": 1,
"explanation": "The International Beacon Project uses fixed beacon slots, so keeping those narrow ranges clear preserves their propagation-monitoring value.",
"source": "https://www.iaru-r1.org/wp-content/uploads/2021/06/hf_r1_bandplan.pdf",
"confidence": 7
},
"BE411": {
"revision": 1,
"explanation": "Uplink is the direction from an earth station up to the satellite.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE412": {
"revision": 1,
"explanation": "Downlink is the direction from the satellite down to earth stations.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE413": {
"revision": 1,
"explanation": "Azimuth is the horizontal bearing angle used to point an antenna around the horizon.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE414": {
"revision": 1,
"explanation": "Elevation is the vertical pointing angle above the horizon used to track a satellite.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE415": {
"revision": 1,
"explanation": "OSCAR expands to Orbiting Satellite Carrying Amateur Radio, the usual name for amateur-radio satellites.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BE416": {
"revision": 1,
"explanation": "A satellite transponder receives signals on one band, translates them to another frequency range, and retransmits them back toward Earth.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BF101": {
"revision": 1,
"explanation": "Outside amateur radio, the internationally recognised distress signals are Mayday for voice and SOS for Morse or signalling.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BF102": {
"revision": 1,
"explanation": "AFuV §16 forbids using the international distress, urgency, and safety signals of maritime and aeronautical mobile services in amateur radio.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"BF103": {
"revision": 1,
"explanation": "If normal communication is unavailable, amateur radio can support emergency assistance by relaying the request to someone who can contact police or rescue services.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__2.html",
"confidence": 9
},
"BF104": {
"revision": 1,
"explanation": "The first task is accurate copying: listen and write down facts before transmitting so the emergency information is not lost or distorted.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BF105": {
"revision": 1,
"explanation": "If a rescue organisation has taken the traffic, extra amateur transmissions only risk interference, so the right action is to stay clear.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BF106": {
"revision": 1,
"explanation": "When no one else answers and you can help, acknowledging the distress traffic and alerting official emergency services is the useful relay path.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__2.html",
"confidence": 9
},
"BF107": {
"revision": 1,
"explanation": "After relaying a distress message, remaining reachable lets you pass updates until professional help arrives or releases you.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BF108": {
"revision": 1,
"explanation": "Germany is UTC+2 during MESZ, so 23:00 UTC is 01:00 MESZ on the following local date.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BF109": {
"revision": 1,
"explanation": "IARU Region 1 designates these HF centres of activity for emergency communication, so they should be kept clear for that use.",
"source": "https://www.iaru-r1.org/about-us/committees-and-working-groups/emcomm/emergency-communications-frequencies/",
"confidence": 7
},
"BG101": {
"revision": 1,
"explanation": "A logbook is the station diary: usually voluntary, but it can become mandatory when required for a particular station or case.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG102": {
"revision": 1,
"explanation": "If log keeping is ordered, a computer log must remain readable for the required period just like a paper log.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG103": {
"revision": 1,
"explanation": "Changing log software must not make ordered log data inaccessible, because the records may need later inspection.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG104": {
"revision": 1,
"explanation": "A QSL card confirms that a QSO took place and can serve as evidence for awards that require worked stations or countries.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG105": {
"revision": 1,
"explanation": "A useful QSL must identify both stations and the contact: call signs, UTC date/time, band, mode, and signal report are the minimum facts.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG106": {
"revision": 1,
"explanation": "UTC avoids local time-zone and daylight-saving ambiguity, making it easier for foreign stations to match the card to their log.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG107": {
"revision": 1,
"explanation": "MEZ is UTC+1, so 15:30 local standard time is 14:30 UTC.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG108": {
"revision": 1,
"explanation": "MESZ is UTC+2, so 13:30 local daylight-saving time is 11:30 UTC.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG109": {
"revision": 1,
"explanation": "'QSL via K8PYD' means K8PYD manages cards for HZ1HZ, so sending through that manager is the route to confirmation.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG110": {
"revision": 1,
"explanation": "Direct QSL mailing needs a current address, which is why operators use callbooks or online call-sign information.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"BG111": {
"revision": 1,
"explanation": "Electronic QSL systems and log uploads confirm the same QSO facts without exchanging a physical card.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"EA101": {
"revision": 1,
"explanation": "Capacitance is charge stored per voltage, $C = Q/U$, and its named SI-derived unit is the farad.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 8
},
"EA102": {
"revision": 1,
"explanation": "Inductance describes magnetic flux linkage per current; the named SI-derived unit for it is the henry.",
"source": "https://50ohm.de/EA_spule_1.html",
"confidence": 8
},
"EA103": {
"revision": 1,
"explanation": "For a plate field, $E = U/d$, so the unit is volts divided by metres: V/m.",
"source": "https://50ohm.de/EA_e_feld.html",
"confidence": 8
},
"EA104": {
"revision": 1,
"explanation": "For a long straight conductor, $H = I/(2\\pi r)$, so magnetic field strength has amperes divided by metres: A/m.",
"source": "https://50ohm.de/EA_h_feld.html",
"confidence": 8
},
"EA105": {
"revision": 2,
"explanation": "Bandwidth is a frequency interval, so it is measured in hertz just like frequency.",
"source": "https://50ohm.de/E_slide_e_modulation.html",
"confidence": 7
},
"EA106": {
"revision": 1,
"explanation": "A data rate counts transferred bits per unit time, so the usual unit is bit/s rather than baud or hertz.",
"source": "https://50ohm.de/NEA_datenuebertragungsdrate.html",
"confidence": 8
},
"EA107": {
"revision": 1,
"explanation": "Power ratios in dB use $10\\log_{10}(P_2/P_1)$; doubling power gives $10\\log_{10}(2) \\approx 3$ dB.",
"source": "https://50ohm.de/E_dezibel_1.html",
"confidence": 8
},
"EA108": {
"revision": 1,
"explanation": "$0.00042$ A equals $420 \\cdot 10^{-6}$ A because moving the decimal six places expresses the value in micro-units.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA109": {
"revision": 1,
"explanation": "$0.042$ A equals $42 \\cdot 10^{-3}$ A because milli means $10^{-3}$.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA110": {
"revision": 1,
"explanation": "$4,200,000$ Hz is $4.2 \\cdot 10^6$ Hz in scientific notation.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA111": {
"revision": 1,
"explanation": "$0.01$ mV is $0.01 \\cdot 10^{-3}$ V, which is $10 \\cdot 10^{-6}$ V.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA112": {
"revision": 1,
"explanation": "$0.002$ MOhm is $0.002 \\cdot 10^6$ ohm, which is $2 \\cdot 10^3$ ohm.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA113": {
"revision": 1,
"explanation": "$2 \\cdot 10^{-7}$ W divided by $10^{-6}$ W/µW gives $0.2$ µW.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA114": {
"revision": 1,
"explanation": "$5 \\cdot 10^{-1}$ W is $0.5$ W; multiplying by 1000 converts that to 500 mW.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA115": {
"revision": 1,
"explanation": "Micro is $10^{-6}$ and nano is $10^{-9}$, so $0.22$ µF is $0.22 \\cdot 1000 = 220$ nF.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA116": {
"revision": 1,
"explanation": "Kilo to mega divides by 1000, so 3750 kHz is 3.750 MHz.",
"source": "https://50ohm.de/NEA_zehnerpotenzen.html",
"confidence": 8
},
"EA201": {
"revision": 1,
"explanation": "Digital circuits can represent two robust electrical states as 0 and 1, so binary maps naturally to switching devices such as transistors.",
"source": "https://50ohm.de/EA_binaer.html",
"confidence": 8
},
"EA202": {
"revision": 1,
"explanation": "Each bit doubles the number of possible states; with 3 bits there are $2^3 = 8$ states.",
"source": "https://50ohm.de/EA_binaer.html",
"confidence": 8
},
"EA203": {
"revision": 1,
"explanation": "Each bit doubles the number of possible states; with 4 bits there are $2^4 = 16$ states.",
"source": "https://50ohm.de/EA_binaer.html",
"confidence": 8
},
"EA204": {
"revision": 1,
"explanation": "A five-bit binary number has $2^5$ possible combinations, so it can represent 32 values.",
"source": "https://50ohm.de/EA_binaer.html",
"confidence": 8
},
"EA205": {
"revision": 1,
"explanation": "$01001110_2 = 64 + 8 + 4 + 2 = 78$; the leading zero only pads the width.",
"source": "https://50ohm.de/EA_binaer.html",
"confidence": 8
},
"EA206": {
"revision": 1,
"explanation": "$10001110_2 = 128 + 8 + 4 + 2 = 142$.",
"source": "https://50ohm.de/EA_binaer.html",
"confidence": 8
},
"EA207": {
"revision": 1,
"explanation": "$10011100_2 = 128 + 16 + 8 + 4 = 156$.",
"source": "https://50ohm.de/EA_binaer.html",
"confidence": 8
},
"EA208": {
"revision": 1,
"explanation": "$11111000_2 = 128 + 64 + 32 + 16 + 8 = 248$.",
"source": "https://50ohm.de/EA_binaer.html",
"confidence": 8
},
"EB101": {
"revision": 2,
"explanation": "Between large parallel plates the field lines are almost straight, parallel, and evenly spaced, so the approximation is a homogeneous electric field.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 8
},
"EB102": {
"revision": 2,
"explanation": "For a plate capacitor, $E = U/d$. With $d = 0.6$ cm $= 0.006$ m, $E = 9/0.006 = 1500$ V/m.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 8
},
"EB103": {
"revision": 2,
"explanation": "Use $E = U/d$ and convert $0.15$ mm to $1.5 \\cdot 10^{-4}$ m. Thus $300/(1.5 \\cdot 10^{-4}) = 2.0 \\cdot 10^6$ V/m = 2000 kV/m.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 8
},
"EB104": {
"revision": 2,
"explanation": "Breakdown strength is an electric field strength, so $U = E \\cdot d$. $400$ kV/cm across $0.15$ mm gives $400 \\cdot 0.015 = 6$ kV.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 8
},
"EB105": {
"revision": 2,
"explanation": "At a vertical antenna the electric field lines run between the conductor and the surrounding reference/ground; the concentric loops around the conductor are the magnetic field, not the marked vertical electric lines.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 7
},
"EB201": {
"revision": 1,
"explanation": "A current through a straight conductor creates magnetic field lines that close around the conductor; in the simple straight-wire case they are concentric circles.",
"source": "https://50ohm.de/EA_h_feld.html",
"confidence": 8
},
"EB202": {
"revision": 2,
"explanation": "A long current-carrying solenoid concentrates nearly parallel magnetic field lines inside the winding, so its interior field is approximately homogeneous and magnetic.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 8
},
"EB203": {
"revision": 1,
"explanation": "For a toroidal core, $H = NI/l_m$ with $l_m = \\pi d$. Here $H = 6 \\cdot 2.5/(\\pi \\cdot 0.026) \\approx 183.6$ A/m.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EB204": {
"revision": 1,
"explanation": "Iron is ferromagnetic at room temperature; copper and aluminium are not ferromagnetic, and chromium is not the standard room-temperature ferromagnet used here.",
"source": "https://50ohm.de/E_spule_1.html",
"confidence": 8
},
"EB205": {
"revision": 1,
"explanation": "A conductive copper or aluminium core supports induced RF currents that oppose field penetration, so the effective magnetic-field cross-section of the coil is reduced. The 50ohm page notes that the catalog wording is simplified, so this is partly a memorize-the-official-answer item.",
"source": "https://50ohm.de/NEA_spule_1.html",
"confidence": 7
},
"EB206": {
"revision": 2,
"explanation": "Around a vertical current-carrying antenna conductor, the closed concentric loops are magnetic field lines. The electric field lines are the open/vertical ones tied to the conductor and ground reference.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 7
},
"EB301": {
"revision": 2,
"explanation": "Radio radiation needs time-varying fields. A time-varying current in a conductor, such as an antenna, produces coupled electric and magnetic field components.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 8
},
"EB302": {
"revision": 2,
"explanation": "An electromagnetic wave propagates because changing electric and magnetic fields continually sustain each other; neither field travels independently in the far-field wave model.",
"source": "https://50ohm.de/NEA_slide_nea_em_feld.html",
"confidence": 8
},
"EB303": {
"revision": 1,
"explanation": "In free-space far-field propagation the electric and magnetic field vectors are transverse to each other, so their angle is $90^\\circ$.",
"source": "https://50ohm.de/NEA_fernfeld.html",
"confidence": 8
},
"EB304": {
"revision": 1,
"explanation": "In an undisturbed far field, the $E$ field, $H$ field, and propagation direction form a mutually perpendicular triad.",
"source": "https://50ohm.de/NEA_fernfeld.html",
"confidence": 8
},
"EB305": {
"revision": 2,
"explanation": "Electromagnetic-wave polarization is defined by the orientation or motion of the electric-field vector, not by the magnetic field or travel direction.",
"source": "https://50ohm.de/NEA_polarisation_2.html",
"confidence": 8
},
"EB306": {
"revision": 2,
"explanation": "Polarization follows the electric-field vector in the drawing. Here that vector lies horizontally, so the wave is horizontally polarized.",
"source": "https://50ohm.de/NEA_polarisation_2.html",
"confidence": 7
},
"EB307": {
"revision": 2,
"explanation": "Polarization is read from the electric-field vector. In this figure the electric field is vertical, so the wave is vertically polarized.",
"source": "https://50ohm.de/NEA_polarisation_2.html",
"confidence": 7
},
"EB308": {
"revision": 2,
"explanation": "When the electric-field direction rotates during propagation rather than staying along one fixed line, the wave is circularly polarized.",
"source": "https://50ohm.de/NEA_polarisation_2.html",
"confidence": 7
},
"EB309": {
"revision": 2,
"explanation": "For a linear antenna, the transmitted wave's polarization follows the orientation of the radiating element in the main direction. The shown elements are horizontal, so the signal is horizontally polarized.",
"source": "https://50ohm.de/NEA_polarisation_2.html",
"confidence": 7
},
"EB310": {
"revision": 2,
"explanation": "A linearly radiating element gives polarization in the same orientation as the electric field it launches. The shown main-direction field is vertical, so the signal is vertically polarized.",
"source": "https://50ohm.de/NEA_polarisation_2.html",
"confidence": 7
},
"EB311": {
"revision": 1,
"explanation": "Use $\\lambda = c/f$ with $c \\approx 300$ Mm/s. $300/1.84 \\approx 163$, so 1.84 MHz corresponds to about 163 m.",
"source": "https://50ohm.de/NE_wellenlaenge_2.html",
"confidence": 8
},
"EB312": {
"revision": 1,
"explanation": "Using $\\lambda \\approx 300/f_{MHz}$, $300/21 \\approx 14.29$ m.",
"source": "https://50ohm.de/NE_wellenlaenge_2.html",
"confidence": 8
},
"EB313": {
"revision": 1,
"explanation": "Using $\\lambda \\approx 300/f_{MHz}$, $300/28.5 \\approx 10.5$ m.",
"source": "https://50ohm.de/NE_wellenlaenge_2.html",
"confidence": 8
},
"EB314": {
"revision": 1,
"explanation": "Rearrange $\\lambda = c/f$ to $f \\approx 300/\\lambda$ in MHz for metres. $300/80.0 = 3.75$ MHz.",
"source": "https://50ohm.de/NE_wellenlaenge_2.html",
"confidence": 8
},
"EB315": {
"revision": 1,
"explanation": "A wavelength of 30 mm is 0.03 m. $f = c/\\lambda \\approx 3 \\cdot 10^8 / 0.03 = 1 \\cdot 10^{10}$ Hz = 10 GHz.",
"source": "https://50ohm.de/NE_wellenlaenge_2.html",
"confidence": 8
},
"EB316": {
"revision": 1,
"explanation": "A wavelength of 10 cm is 0.1 m. $f = c/\\lambda \\approx 3 \\cdot 10^8 / 0.1 = 3 \\cdot 10^9$ Hz = 3 GHz.",
"source": "https://50ohm.de/NE_wellenlaenge_2.html",
"confidence": 8
},
"EB401": {
"revision": 2,
"explanation": "For a sine wave, the peak value is RMS times sqrt(2). Mains 230 V is an RMS value, so 230 * 1.414 is about 325 V.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 8
},
"EB402": {
"revision": 2,
"explanation": "Peak-to-peak voltage is twice the peak value. From 230 V RMS, the peak is about 325 V, so peak-to-peak is about 650 V, rounded here to 651 V.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 8
},
"EB403": {
"revision": 2,
"explanation": "For a sine wave, peak voltage is RMS times sqrt(2): 12 V * 1.414 is about 17 V. Peak-to-peak is twice that, about 34 V.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 8
},
"EB404": {
"revision": 2,
"explanation": "For a sine wave, RMS is peak divided by sqrt(2). 12 V / 1.414 is about 8.5 V.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 8
},
"EB405": {
"revision": 2,
"explanation": "A DC voltage that gives the same heating power as a sine wave is the RMS value. For a 1 V sine peak, RMS is 1/sqrt(2), about 0.7 V in either polarity.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 8
},
"EB406": {
"revision": 2,
"explanation": "Peak-to-peak voltage is the vertical distance from the lowest trough to the highest crest on the screen. Reading the divisions in the shown trace gives 12 V.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 7
},
"EB407": {
"revision": 2,
"explanation": "The peak-to-peak value is twice the peak value shown in the diagram. A 20 V peak therefore gives 40 V peak-to-peak.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 7
},
"EB408": {
"revision": 2,
"explanation": "Frequency is the reciprocal of period: f = 1/T. With T = 50 microseconds, f = 1/(50e-6 s) = 20000 Hz = 20 kHz.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 8
},
"EB409": {
"revision": 2,
"explanation": "Read one period from the oscilloscope grid, then use f = 1/T. The trace period is about 12 microseconds, so f is about 83.3 kHz.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 7
},
"EB410": {
"revision": 2,
"explanation": "The oscilloscope trace spans 4 divisions at 5 ms/div, so T = 20 ms. f = 1/0.020 s = 50 Hz.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 7
},
"EB411": {
"revision": 2,
"explanation": "The trace period is 4 divisions at 0.03 microseconds/div, so T = 0.12 microseconds. f = 1/T is about 8.33 MHz.",
"source": "https://50ohm.de/NE_oszilloskop_1.html",
"confidence": 7
},
"EB501": {
"revision": 1,
"explanation": "PEP is defined at the crest of the modulation envelope: it is the average power over one RF cycle at that highest envelope point under normal operating conditions.",
"source": "https://life.itu.int/radioclub/rr/art1.pdf",
"confidence": 9
},
"EB502": {
"revision": 1,
"explanation": "Mean transmitter power is averaged over a time interval long enough compared with the lowest modulation frequency period, so it describes the longer-term power delivered to the antenna feed line.",
"source": "https://life.itu.int/radioclub/rr/art1.pdf",
"confidence": 9
},
"EB503": {
"revision": 1,
"explanation": "For a purely ohmic load, AC power formulas keep the same form when voltage and current are RMS values. Peak values would overstate the heating power.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB504": {
"revision": 1,
"explanation": "Combine P = U * I with Ohm's law I = U/R to get P = U^2/R. Solving for voltage gives U = sqrt(P * R).",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB505": {
"revision": 1,
"explanation": "From P = I^2 * R, current is I = sqrt(P/R). From P = U^2/R, voltage is U = sqrt(P * R).",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB506": {
"revision": 1,
"explanation": "Rearrange P = U^2/R to get R = U^2/P, and rearrange P = I^2 * R to get R = P/I^2.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB507": {
"revision": 1,
"explanation": "Use RMS voltage in P = U^2/R for the 50 Ohm load. 100^2/50 = 10000/50 = 200 W.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB508": {
"revision": 1,
"explanation": "Use P = I^2 * R with RMS current. 2^2 * 50 = 4 * 50 = 200 W.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB509": {
"revision": 1,
"explanation": "The resistor power is P = U^2/R. With 10 V across 100 Ohm, P = 100/100 = 1.00 W, so the rating must be at least that.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB510": {
"revision": 1,
"explanation": "Check both limits. The power limit gives U = sqrt(P * R) = sqrt(1 W * 10000 Ohm) = 100 V, which is below the 700 V voltage limit.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB511": {
"revision": 1,
"explanation": "The power limit gives U = sqrt(P * R) = sqrt(6 W * 100000 Ohm) about 775 V. That is below the 1000 V voltage rating, so power is the limiting factor.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB512": {
"revision": 1,
"explanation": "From P = I^2 * R, I = sqrt(P/R). sqrt(23.0/120) is about 0.438 A, or 438 mA.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB513": {
"revision": 1,
"explanation": "A 25 V peak-to-peak sine has a 12.5 V peak, so RMS voltage is 12.5/sqrt(2) about 8.84 V. Through 1000 Ohm, that is about 8.8 mA RMS.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EB514": {
"revision": 1,
"explanation": "With 11 equal resistors in parallel, each resistor can still dissipate 5 W. The total rating is 11 * 5 W = 55 W.",
"source": "https://50ohm.de/EA_leistung_2.html",
"confidence": 8
},
"EC101": {
"revision": 1,
"explanation": "Wirewound resistors can dissipate high power, but the winding adds inductance, so they are best suited to DC and low-frequency high-load use.",
"source": "https://50ohm.de/E_widerstand_materialien.html",
"confidence": 8
},
"EC102": {
"revision": 1,
"explanation": "Metal-film resistors are made for tight value tolerance and low temperature dependence, which is why they are used as precision resistors.",
"source": "https://50ohm.de/E_widerstand_materialien.html",
"confidence": 8
},
"EC103": {
"revision": 1,
"explanation": "Metal-oxide film resistors are relatively low-inductance and stable at higher frequencies, unlike wirewound parts whose winding behaves like an inductor.",
"source": "https://50ohm.de/E_widerstand_materialien.html",
"confidence": 8
},
"EC104": {
"revision": 1,
"explanation": "A VHF/UHF dummy load should behave like a pure resistance. Low stray inductance and capacitance keep the impedance near 50 Ohm as frequency rises.",
"source": "https://50ohm.de/E_widerstand_materialien.html",
"confidence": 8
},
"EC105": {
"revision": 1,
"explanation": "Ten 500 Ohm resistors in parallel give 500/10 = 50 Ohm. Carbon-film parts avoid the wirewound inductance that would spoil a dummy load at RF.",
"source": "https://50ohm.de/E_widerstand_materialien.html",
"confidence": 8
},
"EC106": {
"revision": 1,
"explanation": "Ten equal 500 Ohm resistors in parallel give 50 Ohm, and unwound carbon-film parts keep parasitic inductance low enough for this RF dummy-load use.",
"source": "https://50ohm.de/E_widerstand_materialien.html",
"confidence": 8
},
"EC107": {
"revision": 1,
"explanation": "For VHF dummy loads, unwound metal-oxide resistors are preferred because they can be made low-inductance and thermally robust.",
"source": "https://50ohm.de/E_widerstand_materialien.html",
"confidence": 8
},
"EC108": {
"revision": 1,
"explanation": "NTC thermistors have a deliberately temperature-dependent resistance, making them useful as temperature sensors.",
"source": "https://50ohm.de/E_widerstand_ntc_ptc.html",
"confidence": 8
},
"EC109": {
"revision": 1,
"explanation": "The symbol shows a temperature-dependent resistor whose resistance falls as temperature rises; that negative temperature coefficient is an NTC thermistor.",
"source": "https://50ohm.de/E_widerstand_ntc_ptc.html",
"confidence": 7
},
"EC110": {
"revision": 1,
"explanation": "An NTC symbol indicates temperature dependence with resistance decreasing as temperature increases. In the shown choices, that is the symbol with the temperature arrow up and resistance/conductance indication downward as described on 50ohm.",
"source": "https://50ohm.de/E_widerstand_ntc_ptc.html",
"confidence": 7
},
"EC111": {
"revision": 1,
"explanation": "A PTC thermistor has a positive temperature coefficient: as temperature rises, resistance rises. The matching symbol is the one with both temperature and resistance trend upward.",
"source": "https://50ohm.de/E_widerstand_ntc_ptc.html",
"confidence": 7
},
"EC112": {
"revision": 1,
"explanation": "A 10 percent tolerance on 5.6 kOhm is 0.56 kOhm. The possible range is 5.6 - 0.56 to 5.6 + 0.56 kOhm, or 5040 to 6160 Ohm.",
"source": "https://50ohm.de/NE_widerstand_toleranz.html",
"confidence": 8
},
"EC113": {
"revision": 1,
"explanation": "Green-blue-red is 56 times 100, so the nominal value is 5600 Ohm. Silver means 10 percent tolerance, giving 5040 to 6160 Ohm.",
"source": "https://50ohm.de/NE_widerstand_toleranz.html",
"confidence": 8
},
"EC114": {
"revision": 1,
"explanation": "Common three-digit SMD resistor marking uses the first digits as significant figures and the last digit as the power of ten multiplier.",
"source": "https://50ohm.de/E_widerstand_smd.html",
"confidence": 8
},
"EC115": {
"revision": 1,
"explanation": "The marking 103 means 10 followed by 3 zeros: 10 * 10^3 Ohm = 10000 Ohm = 10 kOhm.",
"source": "https://50ohm.de/E_widerstand_smd.html",
"confidence": 8
},
"EC116": {
"revision": 1,
"explanation": "The marking 221 means 22 followed by one zero: 22 * 10^1 Ohm = 220 Ohm.",
"source": "https://50ohm.de/E_widerstand_smd.html",
"confidence": 8
},
"EC117": {
"revision": 1,
"explanation": "The marking 223 means 22 followed by three zeros: 22 * 10^3 Ohm = 22000 Ohm = 22 kOhm.",
"source": "https://50ohm.de/E_widerstand_smd.html",
"confidence": 8
},
"EC201": {
"revision": 1,
"explanation": "An initially discharged capacitor charges quickly at first, then the voltage rise flattens as it approaches the supply voltage. That is the rising exponential charging curve.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 7
},
"EC202": {
"revision": 1,
"explanation": "A capacitor's AC reactance is inversely proportional to frequency. As frequency increases, an ideal capacitor's opposition to AC decreases.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 8
},
"EC203": {
"revision": 1,
"explanation": "For a plate capacitor, capacitance is proportional to plate area and dielectric constant, and inversely proportional to plate spacing. A larger spacing therefore reduces capacitance.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 8
},
"EC204": {
"revision": 1,
"explanation": "Increasing the plate distance puts the same plates farther apart, so the plate capacitor's capacitance falls.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 8
},
"EC205": {
"revision": 1,
"explanation": "Ideal plate-capacitor capacitance depends on geometry and dielectric material, not on the applied voltage.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 8
},
"EC206": {
"revision": 1,
"explanation": "A variable capacitor with rotor plates moving between fixed stator plates is a Drehkondensator; rotation changes the overlapping plate area and thus the capacitance.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 8
},
"EC207": {
"revision": 1,
"explanation": "Electrolytic capacitors are polarized because their oxide dielectric depends on the correct DC polarity; reversed polarity can damage them.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 8
},
"EC301": {
"revision": 1,
"explanation": "After DC is applied through a resistor, an inductor initially opposes the current change, so the voltage across it starts high and then decays toward zero.",
"source": "https://50ohm.de/EA_spule_1.html",
"confidence": 7
},
"EC302": {
"revision": 1,
"explanation": "The coil initially limits current because it opposes the sudden current change, so the lamp fed through the plain resistor lights first.",
"source": "https://50ohm.de/EA_spule_1.html",
"confidence": 8
},
"EC303": {
"revision": 1,
"explanation": "An ideal inductor's AC reactance is proportional to frequency, so its opposition to AC rises as frequency increases.",
"source": "https://50ohm.de/EA_spule_1.html",
"confidence": 8
},
"EC304": {
"revision": 1,
"explanation": "Any current-carrying conductor has a magnetic field and therefore some inductance, even if it is only a straight piece of wire.",
"source": "https://50ohm.de/E_spule_1.html",
"confidence": 8
},
"EC305": {
"revision": 1,
"explanation": "For the same winding, shortening the coil length increases inductance. Compressing the cylindrical coil in the length direction therefore raises L.",
"source": "https://50ohm.de/EA_spule_1.html",
"confidence": 8
},
"EC306": {
"revision": 1,
"explanation": "For the same turns and cross-section, inductance is inversely proportional to coil length. Doubling the length halves 12 microhenry to 6 microhenry.",
"source": "https://50ohm.de/EA_spule_1.html",
"confidence": 8
},
"EC307": {
"revision": 1,
"explanation": "Inductance is proportional to the square of the number of turns. Doubling the turns multiplies 12 microhenry by 4, giving 48 microhenry.",
"source": "https://50ohm.de/EA_spule_1.html",
"confidence": 8
},
"EC401": {
"revision": 1,
"explanation": "A 15:1 transformer ratio steps the 230 V primary down by 15. 230/15 is about 15.3 V, so the secondary is about 15 V.",
"source": "https://50ohm.de/E_uebertrager_1.html",
"confidence": 8
},
"EC402": {
"revision": 1,
"explanation": "If the primary has five times as many turns as the secondary, the secondary voltage is one fifth of the primary voltage. 230/5 = 46 V.",
"source": "https://50ohm.de/E_uebertrager_1.html",
"confidence": 8
},
"EC403": {
"revision": 1,
"explanation": "Turns ratio follows voltage ratio: 230/11.5 = 20. The secondary therefore has 600/20 = 30 turns.",
"source": "https://50ohm.de/E_uebertrager_1.html",
"confidence": 8
},
"EC404": {
"revision": 1,
"explanation": "The secondary voltage is four times the primary voltage, so the secondary must have four times the turns. 150 * 4 = 600 turns.",
"source": "https://50ohm.de/E_uebertrager_1.html",
"confidence": 8
},
"EC501": {
"revision": 1,
"explanation": "In reverse bias a normal diode blocks current except for a tiny leakage current, so it behaves like a high resistance.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC502": {
"revision": 1,
"explanation": "A diode conducts mainly in one direction, so it can pass one half-cycle polarity and block the other; that is the basic rectifier function.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC503": {
"revision": 1,
"explanation": "Germanium diodes have a lower forward threshold, roughly 0.2 to 0.4 V, while silicon diodes are typically around 0.6 to 0.8 V.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC504": {
"revision": 1,
"explanation": "A Schottky diode uses a metal-semiconductor junction, giving a low forward voltage and very fast switching compared with ordinary pn diodes.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC505": {
"revision": 1,
"explanation": "On the shown characteristic plot, curve 1 starts conducting at the lowest forward voltage near 0.2 V, which matches a Schottky diode.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC506": {
"revision": 1,
"explanation": "Curve 2 begins conducting around 0.2 to 0.4 V, the typical forward-threshold range for a germanium diode.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC507": {
"revision": 1,
"explanation": "Curve 3 starts its steep rise around 0.6 to 0.8 V, matching the usual silicon-diode forward threshold.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC508": {
"revision": 1,
"explanation": "Curve 4 has the highest forward threshold in the plot, around the LED range, so it represents a light-emitting diode.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC509": {
"revision": 1,
"explanation": "A silicon diode conducts when its anode is about 0.7 V more positive than its cathode. In the selected drawing, the right/anode side is 1.3 V and the left/cathode side is 0.6 V.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC510": {
"revision": 1,
"explanation": "Use the silicon-diode rule: anode about 0.7 V above cathode. The selected drawing has 0.3 V on the anode side and -0.4 V on the cathode side.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC511": {
"revision": 1,
"explanation": "Forward conduction depends on voltage difference, not whether the node voltages are positive. Here the anode is -1.3 V and the cathode is -2.0 V, so the anode is 0.7 V higher.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC512": {
"revision": 1,
"explanation": "The conducting silicon-diode case is the one with the anode about 0.7 V above the cathode. In the selected drawing, -3.0 V is 0.7 V higher than -3.7 V.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC513": {
"revision": 1,
"explanation": "A silicon diode becomes forward-biased when the anode is about 0.7 V above the cathode. 5.7 V at the anode and 5.0 V at the cathode meets that condition.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC514": {
"revision": 1,
"explanation": "The circuit is a current-limited LED: the resistor sets the LED current and the diode symbol with outgoing arrows indicates light emission.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC515": {
"revision": 1,
"explanation": "The resistor must drop the remaining voltage: 5.0 V - 1.4 V = 3.6 V. At 20 mA, R = 3.6/0.020 = 180 Ohm.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC516": {
"revision": 1,
"explanation": "The resistor drops 5.5 V - 1.75 V = 3.75 V. With 25 mA, R = 3.75/0.025 = 150 Ohm and P = 3.75 * 0.025 about 0.094 W, so 0.1 W is needed.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC517": {
"revision": 1,
"explanation": "The bent cathode bar is the distinctive schematic mark for a Zener diode, used in reverse breakdown operation.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC518": {
"revision": 1,
"explanation": "A Zener diode is designed to operate in reverse breakdown at a defined voltage, making it useful for voltage stabilization.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC519": {
"revision": 1,
"explanation": "The shown circuit puts a Zener diode across the output after a series resistor, the standard simple shunt voltage stabilizer arrangement.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC520": {
"revision": 1,
"explanation": "For positive output stabilization, the Zener diode is placed after the series resistor and reverse-biased across the output. That lets it clamp the output near its Zener voltage.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 7
},
"EC521": {
"revision": 1,
"explanation": "The resistor drops 13.8 V - 5 V = 8.8 V at 30 mA. R = 8.8/0.030 = 293 Ohm approximately.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC522": {
"revision": 1,
"explanation": "The series resistor carries both Zener and load current: 25 mA + 20 mA = 45 mA. With a 4.7 V output, R = (13.8 - 4.7)/0.045 about 202 Ohm.",
"source": "https://50ohm.de/EA_diode_1.html",
"confidence": 8
},
"EC601": {
"revision": 1,
"explanation": "A transistor can be biased to switch fully on/off, to operate linearly as an amplifier, or in some cases to behave as a controllable resistance.",
"source": "https://50ohm.de/NEA_transistor_1.html",
"confidence": 8
},
"EC602": {
"revision": 1,
"explanation": "A transistor is built from semiconductor regions; the usual bipolar types use alternating n- and p-doped semiconductor zones.",
"source": "https://50ohm.de/NEA_transistor_1.html",
"confidence": 8
},
"EC603": {
"revision": 1,
"explanation": "In the practical current-control model, a small base current controls a much larger collector current; their ratio is the current gain.",
"source": "https://50ohm.de/NEA_transistor_1.html",
"confidence": 8
},
"EC604": {
"revision": 1,
"explanation": "Bipolar junction transistors are the NPN and PNP types. FET names such as MOS-FET or junction-FET belong to field-effect transistors, not bipolar transistors.",
"source": "https://50ohm.de/NEA_transistor_1.html",
"confidence": 8
},
"EC605": {
"revision": 2,
"explanation": "A bipolar transistor symbol has base, collector, and emitter terminals, with an emitter arrow; FET symbols use gate, drain, and source structures instead.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 7
},
"EC606": {
"revision": 2,
"explanation": "In an NPN transistor symbol the emitter arrow points outward, matching the common mnemonic 'NPN: Not Pointing iN'.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 7
},
"EC607": {
"revision": 2,
"explanation": "In a PNP transistor symbol the emitter arrow points inward toward the transistor body; 50ohm gives the mnemonic 'PNP: Pfeil Nach Platte'.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 7
},
"EC608": {
"revision": 1,
"explanation": "The three terminals of a bipolar transistor are emitter, base, and collector. Drain, source, and gate are FET terminal names.",
"source": "https://50ohm.de/NEA_transistor_1.html",
"confidence": 8
},
"EC609": {
"revision": 2,
"explanation": "The shown NPN symbol has the collector at terminal 1, the base at terminal 2, and the emitter with the arrow at terminal 3.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 7
},
"EC610": {
"revision": 2,
"explanation": "The base-emitter junction of a conducting silicon bipolar transistor is forward biased at about 0.6 V in the class-E model.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 8
},
"EC611": {
"revision": 1,
"explanation": "The emitter current is the sum of collector current and base current, so in the conducting state the emitter carries the largest current.",
"source": "https://50ohm.de/NEA_transistor_1.html",
"confidence": 8
},
"EC612": {
"revision": 2,
"explanation": "For an NPN transistor, collector current flows when the base is about 0.6 V above the emitter. The selected drawing has +2.0 V at the base and +1.4 V at the emitter.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 7
},
"EC613": {
"revision": 2,
"explanation": "Only the voltage difference matters: for NPN, the base must be about 0.6 V above the emitter. Here -5.6 V is 0.6 V above -6.2 V, so the transistor conducts.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 7
},
"EC614": {
"revision": 2,
"explanation": "For a PNP transistor, collector current flows when the base is about 0.6 V below the emitter. The selected drawing has -2.0 V at the base and -1.4 V at the emitter.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 7
},
"EC615": {
"revision": 2,
"explanation": "For PNP, the base-emitter voltage is negative when conducting: the base is about 0.6 V lower than the emitter. Here +5.6 V at the base and +6.2 V at the emitter satisfy that.",
"source": "https://50ohm.de/NEA_slide_nea_bauelemente.html",
"confidence": 7
},
"ED101": {
"revision": 1,
"explanation": "In a series voltage divider, voltage drops in the same ratio as resistance. If R1 is 5 times R2, then U1 is 5 times U2.",
"source": "https://50ohm.de/NE_spannungsteiler_1.html",
"confidence": 8
},
"ED102": {
"revision": 1,
"explanation": "In a series voltage divider, U1/U2 = R1/R2. If R1 is one sixth of R2, then U1 is one sixth of U2.",
"source": "https://50ohm.de/NE_spannungsteiler_1.html",
"confidence": 8
},
"ED103": {
"revision": 1,
"explanation": "Use the divider rule: U2 = U * R2/(R1 + R2). With 9 V, 10 kOhm, and 20 kOhm, U2 = 9 * 20/30 = 6.0 V.",
"source": "https://50ohm.de/NE_spannungsteiler_1.html",
"confidence": 8
},
"ED104": {
"revision": 1,
"explanation": "For two parallel resistors, Rg = R1*R2/(R1+R2). 100*400/(100+400) = 40000/500 = 80 Ohm.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 8
},
"ED105": {
"revision": 1,
"explanation": "For two parallel resistors, Rg = R1*R2/(R1+R2). 50*200/(50+200) = 10000/250 = 40 Ohm.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 8
},
"ED106": {
"revision": 1,
"explanation": "For n equal resistors in parallel, Rg = R/n. Therefore each resistor is R = n*Rg = 3*1.7 kOhm = 5.1 kOhm.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 8
},
"ED107": {
"revision": 1,
"explanation": "With three equal resistors, the allowed total power is the sum of the individual ratings when the load is shared. That gives 3*1 W = 3 W in both series and parallel arrangements.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 8
},
"ED108": {
"revision": 1,
"explanation": "R1 and R2 are in series, giving 500 + 500 = 1000 Ohm. That 1000 Ohm branch is in parallel with R3 = 1000 Ohm, so the total is 500 Ohm.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 7
},
"ED109": {
"revision": 1,
"explanation": "R1 and R2 first add in series: 500 Ohm + 1.5 kOhm = 2 kOhm. That is in parallel with R3 = 2 kOhm, so the result is 1 kOhm.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 7
},
"ED110": {
"revision": 1,
"explanation": "The two 1 kOhm resistors are parallel, so they reduce to 500 Ohm. In series with the remaining 500 Ohm, the total is 1 kOhm.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 7
},
"ED111": {
"revision": 1,
"explanation": "R2 and R3 are both 2 kOhm in parallel, giving 1 kOhm. Adding the series R1 of 1 kOhm gives 2 kOhm total.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 7
},
"ED112": {
"revision": 1,
"explanation": "R2 and R3 are parallel: 3 kOhm || 1.5 kOhm = 1 kOhm. Add the series R1 of 1 kOhm to get 2 kOhm.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 7
},
"ED113": {
"revision": 1,
"explanation": "R1, R2, and R3 are parallel: 10 kOhm || 2.5 kOhm || 500 Ohm = 400 Ohm. Adding the series 600 Ohm resistor gives 1 kOhm.",
"source": "https://50ohm.de/E_reihe_parallel_widerstand.html",
"confidence": 7
},
"ED114": {
"revision": 1,
"explanation": "Reduce the obvious groups step by step: 50 Ohm + 50 Ohm gives 100 Ohm, 100 Ohm in parallel with 100 Ohm gives 50 Ohm, then the remaining series parts total 250 Ohm.",
"source": "https://50ohm.de/NE_reihe_parallel_widerstandsnetz_1.html",
"confidence": 7
},
"ED115": {
"revision": 1,
"explanation": "Combine the clear series and parallel subgroups in stages; the network reduces to a final series sum of 550 Ohm.",
"source": "https://50ohm.de/NE_reihe_parallel_widerstandsnetz_1.html",
"confidence": 7
},
"ED116": {
"revision": 1,
"explanation": "After reducing the drawn subgroups, the remaining series values are 400 Ohm, 200 Ohm, 200 Ohm, and 150 Ohm. Their sum is 950 Ohm.",
"source": "https://50ohm.de/NE_reihe_parallel_widerstandsnetz_1.html",
"confidence": 7
},
"ED117": {
"revision": 1,
"explanation": "Parallel capacitances add directly. 0.1 uF = 100 nF and 50000 pF = 50 nF, so 100 + 150 + 50 = 300 nF = 0.3 uF.",
"source": "https://50ohm.de/NEA_reihe_parallel_kondensator.html",
"confidence": 8
},
"ED118": {
"revision": 1,
"explanation": "Parallel capacitors add directly after unit conversion: 22 nF + 0.033 uF (33 nF) + 15000 pF (15 nF) = 70 nF = 0.070 uF.",
"source": "https://50ohm.de/NEA_reihe_parallel_kondensator.html",
"confidence": 8
},
"ED119": {
"revision": 1,
"explanation": "For equal capacitors in series, Cg = C/n. Three 0.33 uF capacitors therefore give 0.33/3 = 0.110 uF.",
"source": "https://50ohm.de/NEA_reihe_parallel_kondensator.html",
"confidence": 8
},
"ED120": {
"revision": 1,
"explanation": "Convert 200000 nF to 200 uF. The series formula gives 1/Cg = 1/100 + 1/200 + 1/200, so Cg = 50 uF.",
"source": "https://50ohm.de/NEA_reihe_parallel_kondensator.html",
"confidence": 8
},
"ED121": {
"revision": 1,
"explanation": "C1 and C2 are equal 10 nF capacitors in series, so their equivalent is 5 nF. In parallel with C3 = 5 nF, the total is 10 nF.",
"source": "https://50ohm.de/NEA_reihe_parallel_kondensator.html",
"confidence": 7
},
"ED122": {
"revision": 1,
"explanation": "C2 and C3 are parallel, giving 1 uF + 1 uF = 2 uF. That is in series with C1 = 2 uF, so two equal 2 uF capacitors in series give 1.0 uF.",
"source": "https://50ohm.de/NEA_reihe_parallel_kondensator.html",
"confidence": 7
},
"ED123": {
"revision": 1,
"explanation": "C2 and C3 are parallel, so 4 nF + 4 nF = 8 nF. That 8 nF equivalent is in series with C1 = 8 nF, giving 4 nF.",
"source": "https://50ohm.de/NEA_reihe_parallel_kondensator.html",
"confidence": 7
},
"ED124": {
"revision": 1,
"explanation": "Convert C3 = 100000 pF to 100 nF. C2 and C3 are parallel, giving 200 nF; that is in series with C1 = 200 nF, so the total is 100 nF.",
"source": "https://50ohm.de/NEA_reihe_parallel_kondensator.html",
"confidence": 7
},
"ED201": {
"revision": 1,
"explanation": "The graph passes low frequencies and attenuates frequencies above the cutoff, which is the defining response of a low-pass filter.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED202": {
"revision": 1,
"explanation": "The graph attenuates low frequencies and passes higher frequencies after the cutoff, so it is a high-pass response.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED203": {
"revision": 1,
"explanation": "The curve passes only a middle frequency range and attenuates both low and high frequencies, which is a band-pass response.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED204": {
"revision": 1,
"explanation": "The curve passes frequencies on both sides but rejects a middle range around resonance, so it is a band-stop response.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED205": {
"revision": 1,
"explanation": "A series resonant circuit has minimum impedance at resonance because inductive and capacitive reactance cancel, giving the V-shaped impedance curve.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 8
},
"ED206": {
"revision": 1,
"explanation": "A parallel resonant circuit has maximum impedance at resonance, producing the peaked impedance curve shown.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 8
},
"ED207": {
"revision": 1,
"explanation": "At resonance a parallel LC circuit presents a very high impedance; away from resonance one branch becomes comparatively low impedance.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 8
},
"ED208": {
"revision": 1,
"explanation": "The circuit takes the output after a series resistor with a capacitor shunting high frequencies to ground, so low frequencies pass and high frequencies are attenuated: a low-pass filter.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED209": {
"revision": 1,
"explanation": "A series inductor followed by a shunt capacitor passes low frequencies: the inductor is low impedance at low frequency and the capacitor shunts high frequency components.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED210": {
"revision": 1,
"explanation": "For microphone audio low-pass filtering, the selected RC network uses capacitors to bypass high-frequency components while the wanted lower audio range remains at the output.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED211": {
"revision": 1,
"explanation": "A series capacitor followed by a resistor load is a high-pass: the capacitor blocks low-frequency components and passes higher-frequency components more easily.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED212": {
"revision": 1,
"explanation": "With a series capacitor and a shunt inductor, low frequencies are shunted through the inductor while higher frequencies pass through the capacitor path, so the circuit is a high-pass.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED213": {
"revision": 1,
"explanation": "The selected LC ladder has a series capacitor path with shunt inductors, the high-pass pattern: low frequencies are bypassed, higher frequencies are passed.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED214": {
"revision": 1,
"explanation": "A parallel resonant circuit placed in series with the signal path has high impedance at resonance and blocks that frequency, so it is a Sperrkreis.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED215": {
"revision": 1,
"explanation": "A series resonant LC branch connected across the signal path has low impedance at resonance and diverts that frequency away from the output, so it is a Saugkreis.",
"source": "https://50ohm.de/EA_schwingkreis_1.html",
"confidence": 7
},
"ED216": {
"revision": 1,
"explanation": "HF filters need low-loss, high-Q capacitors with small parasitic effects; ceramic and air capacitors are preferred over electrolytics.",
"source": "https://50ohm.de/EA_kondensator_1.html",
"confidence": 8
},
"ED301": {
"revision": 1,
"explanation": "A useful DC supply should keep its output voltage nearly constant under load; otherwise the connected radio stages see supply-voltage changes.",
"source": "https://50ohm.de/EA_spannungsquelle.html",
"confidence": 8
},
"ED302": {
"revision": 1,
"explanation": "Switch-mode supplies convert power at high switching frequency, allowing small transformers and heat sinks, so they are efficient, light, and compact.",
"source": "https://50ohm.de/NEA_schaltnetzteil_1.html",
"confidence": 8
},
"ED303": {
"revision": 1,
"explanation": "The high-frequency switching action can generate RF interference unless the supply is well filtered and shielded.",
"source": "https://50ohm.de/NEA_schaltnetzteil_1.html",
"confidence": 8
},
"ED304": {
"revision": 1,
"explanation": "The circuit is a single-diode half-wave rectifier. The load voltage contains only the conducting half-cycles, with the opposite half-cycles blocked by the diode.",
"source": "https://50ohm.de/EA_gleichrichter_1.html",
"confidence": 7
},
"ED401": {
"revision": 1,
"explanation": "Power gain means the output signal power is greater than the input signal power. That extra power must come from an external supply, not from the input signal alone.",
"source": "https://50ohm.de/NE_verstaerker.html",
"confidence": 8
},
"ED402": {
"revision": 1,
"explanation": "The shown transistor audio-stage topology is an NF amplifier; it is meant for low-frequency/audio signal amplification, not RF or IF selection.",
"source": "https://50ohm.de/NE_verstaerker.html",
"confidence": 7
},
"ED403": {
"revision": 1,
"explanation": "An HF power amplifier raises the transmitter's RF signal level to the desired output power before feeding the antenna system.",
"source": "https://50ohm.de/NE_verstaerker.html",
"confidence": 8
},
"ED501": {
"revision": 1,
"explanation": "An LC oscillator uses a tuned circuit made from an inductor L and capacitor C; that resonant circuit sets the oscillation frequency.",
"source": "https://50ohm.de/E_oszillatoren.html",
"confidence": 8
},
"ED502": {
"revision": 1,
"explanation": "The LC resonance frequency is inversely related to the square root of capacitance. If C increases, the oscillator frequency decreases.",
"source": "https://50ohm.de/E_oszillatoren.html",
"confidence": 8
},
"ED503": {
"revision": 1,
"explanation": "The LC resonance frequency rises when capacitance falls, because frequency is inversely related to sqrt(L*C).",
"source": "https://50ohm.de/E_oszillatoren.html",
"confidence": 8
},
"ED504": {
"revision": 1,
"explanation": "The LC resonance frequency is inversely related to the square root of inductance. If L increases, the oscillator frequency decreases.",
"source": "https://50ohm.de/E_oszillatoren.html",
"confidence": 8
},
"ED505": {
"revision": 1,
"explanation": "When inductance decreases, the LC product becomes smaller, so the resonant frequency becomes higher.",
"source": "https://50ohm.de/E_oszillatoren.html",
"confidence": 8
},
"ED506": {
"revision": 1,
"explanation": "In a crystal oscillator, the quartz crystal is the frequency-determining resonator.",
"source": "https://50ohm.de/E_oszillatoren.html",
"confidence": 8
},
"ED507": {
"revision": 1,
"explanation": "A quartz crystal's resonance changes much less with temperature and component tolerances than a simple LC circuit, so crystal oscillators are more frequency-stable.",
"source": "https://50ohm.de/E_oszillatoren.html",
"confidence": 8
},
"EE101": {
"revision": 1,
"explanation": "An unmodulated carrier is a steady sine wave with constant amplitude, frequency, and phase; the selected diagram shows that unchanged carrier.",
"source": "https://50ohm.de/E_unmodulierter_traeger.html",
"confidence": 7
},
"EE201": {
"revision": 1,
"explanation": "AM carries both sidebands plus carrier, while SSB suppresses the carrier and one sideband. Therefore SSB needs less than half the bandwidth of AM.",
"source": "https://50ohm.de/E_ssb_2.html",
"confidence": 8
},
"EE202": {
"revision": 1,
"explanation": "In SSB, only one translated sideband is transmitted, so the occupied RF bandwidth is essentially the same as the audio/NF bandwidth being sent.",
"source": "https://50ohm.de/E_ssb_2.html",
"confidence": 8
},
"EE203": {
"revision": 1,
"explanation": "USB places the audio component above the carrier. 21.250 MHz + 0.001 MHz = 21.251 MHz.",
"source": "https://50ohm.de/E_ssb_2.html",
"confidence": 8
},
"EE204": {
"revision": 1,
"explanation": "LSB places the audio component below the carrier and suppresses the carrier in ideal SSB. 3.650 MHz - 0.002 MHz = 3.648 MHz.",
"source": "https://50ohm.de/E_ssb_2.html",
"confidence": 8
},
"EE205": {
"revision": 2,
"explanation": "For SSB voice, RF output follows the audio drive level. Reducing the NF/audio amplitude reduces the modulated transmitter output power.",
"source": "https://50ohm.de/E_slide_e_modulation.html",
"confidence": 8
},
"EE206": {
"revision": 2,
"explanation": "Too little microphone gain gives too little audio drive to the SSB modulator, so the transmitter produces low output power.",
"source": "https://50ohm.de/E_slide_e_modulation.html",
"confidence": 8
},
"EE207": {
"revision": 1,
"explanation": "CW keys one carrier rather than transmitting a full speech spectrum, so its occupied bandwidth is smaller than both SSB voice and AM voice.",
"source": "https://50ohm.de/E_ssb_2.html",
"confidence": 8
},
"EE301": {
"revision": 1,
"explanation": "The shown waveform keeps amplitude essentially constant while the instantaneous carrier frequency changes, which identifies frequency modulation.",
"source": "https://50ohm.de/EA_fm_2.html",
"confidence": 7
},
"EE302": {
"revision": 1,
"explanation": "FM carries information in frequency deviation rather than amplitude, so amplitude noise has less direct effect than it does in SSB.",
"source": "https://50ohm.de/EA_fm_2.html",
"confidence": 8
},
"EE303": {
"revision": 1,
"explanation": "Vehicle electrical noise often appears as amplitude disturbance. FM is least affected because the receiver can limit amplitude and use frequency deviation instead.",
"source": "https://50ohm.de/EA_fm_2.html",
"confidence": 8
},
"EE304": {
"revision": 1,
"explanation": "In FM, a larger frequency deviation spreads the signal over a wider range of frequencies, increasing RF bandwidth.",
"source": "https://50ohm.de/EA_fm_2.html",
"confidence": 8
},
"EE305": {
"revision": 1,
"explanation": "Excessive FM bandwidth is reduced by lowering the deviation setting, because deviation directly determines how far the carrier moves from center frequency.",
"source": "https://50ohm.de/EA_fm_2.html",
"confidence": 8
},
"EE306": {
"revision": 1,
"explanation": "In FM, loudness is represented by the size of the carrier-frequency deviation, not by RF amplitude.",
"source": "https://50ohm.de/EA_fm_2.html",
"confidence": 8
},
"EE401": {
"revision": 1,
"explanation": "Bandwidth is occupied frequency range measured in hertz. Data rate is the amount of information transferred per time, measured in bit/s.",
"source": "https://50ohm.de/NEA_datenuebertragungsdrate.html",
"confidence": 8
},
"EE402": {
"revision": 1,
"explanation": "SSB translates the audio-frequency digimode signal to RF while preserving its narrow bandwidth, which is why modes such as FT8 or BPSK31 are sent through an SSB transmitter path.",
"source": "https://50ohm.de/NEA_digimode_ssb.html",
"confidence": 8
},
"EE403": {
"revision": 1,
"explanation": "With SSB, the RF bandwidth follows the bandwidth of the audio/NF signal. A 50 Hz audio signal therefore occupies about 50 Hz RF bandwidth.",
"source": "https://50ohm.de/NEA_digimode_ssb.html",
"confidence": 8
},
"EE404": {
"revision": 1,
"explanation": "A 2.4 kHz SSB passband can contain several much narrower digimode signals at different audio frequencies, and software can decode one or more of them.",
"source": "https://50ohm.de/NEA_digimode_ssb.html",
"confidence": 8
},
"EE405": {
"revision": 2,
"explanation": "Reporter networks collect received digimode spots by callsign. Sending a suitable signal such as WSPR and then searching the reporting platform shows where it was received.",
"source": "https://50ohm.de/NEA_slide_nea_digitale_uebertragungsverfahren.html",
"confidence": 8
},
"EE406": {
"revision": 1,
"explanation": "ASK changes the carrier amplitude between symbol states while frequency stays recognisably the same; the selected diagram shows those amplitude changes.",
"source": "https://50ohm.de/EA_ask_fsk_afsk.html",
"confidence": 7
},
"EE407": {
"revision": 1,
"explanation": "FSK changes between different carrier frequencies while keeping amplitude essentially constant; the selected diagram shows changing period/frequency.",
"source": "https://50ohm.de/EA_ask_fsk_afsk.html",
"confidence": 7
},
"EE408": {
"revision": 1,
"explanation": "In AFSK, frequency-shift keying is first generated as an audio-frequency signal, which then modulates an RF transmitter such as an FM, AM, or SSB rig.",
"source": "https://50ohm.de/NEA_afsk.html",
"confidence": 8
},
"EE409": {
"revision": 2,
"explanation": "TDMA separates users by time slots: signals take rapid turns on the same frequency rather than transmitting continuously at once.",
"source": "https://50ohm.de/NEA_vielfachzugriff.html",
"confidence": 8
},
"EE410": {
"revision": 2,
"explanation": "FDMA separates simultaneous signals by frequency, so users transmit at the same time but on different frequency channels.",
"source": "https://50ohm.de/NEA_vielfachzugriff.html",
"confidence": 8
},
"EE411": {
"revision": 2,
"explanation": "CDMA lets signals share time and frequency by applying different spreading codes that the receiver uses to separate them.",
"source": "https://50ohm.de/NEA_vielfachzugriff.html",
"confidence": 8
},
"EE412": {
"revision": 1,
"explanation": "In a packet-switched network, packets can be forwarded through intermediate stations or routers when the two endpoints cannot reach each other directly.",
"source": "https://50ohm.de/NEA_paketvermittelte_netzwerke.html",
"confidence": 8
},
"EE413": {
"revision": 1,
"explanation": "The IP address plus subnet mask defines which addresses are on the same local subnet and are reachable directly without routing.",
"source": "https://50ohm.de/NEA_paketvermittelte_netzwerke.html",
"confidence": 8
},
"EE414": {
"revision": 1,
"explanation": "IP is a network protocol, not something limited to the public Internet, so it can also be used in amateur-radio networks such as HAMNET.",
"source": "https://50ohm.de/NEA_paketvermittelte_netzwerke.html",
"confidence": 8
},
"EE415": {
"revision": 1,
"explanation": "SSTV sends still pictures slowly, while ATV is amateur television with moving pictures and much larger bandwidth needs.",
"source": "https://50ohm.de/NEA_digimode_ssb.html",
"confidence": 8
},
"EF101": {
"revision": 1,
"explanation": "The circuit is a detector receiver: the tuned circuit selects the station and the diode recovers the audio envelope without an active oscillator or amplifier.",
"source": "https://50ohm.de/NE_detektorempf%C3%A4nger.html",
"confidence": 7
},
"EF102": {
"revision": 1,
"explanation": "A superhet converts received signals to a fixed IF, so fixed filters can provide much better selectivity than a tuned-radio-frequency receiver.",
"source": "https://50ohm.de/E_ueberlagerungsempfaenger_einfachsuper_1.html",
"confidence": 8
},
"EF201": {
"revision": 1,
"explanation": "A mixer mainly produces the sum and absolute difference: 31.7 MHz + 21 MHz = 52.7 MHz and |31.7 MHz - 21 MHz| = 10.7 MHz.",
"source": "https://50ohm.de/E_mischer.html",
"confidence": 8
},
"EF202": {
"revision": 1,
"explanation": "Mixer products are the sum and absolute difference: 38.7 MHz + 28 MHz = 66.7 MHz and |38.7 MHz - 28 MHz| = 10.7 MHz.",
"source": "https://50ohm.de/E_mischer.html",
"confidence": 8
},
"EF203": {
"revision": 1,
"explanation": "The desired mixer products are sum and difference, so 30 MHz and 39 MHz produce 69 MHz and 9 MHz.",
"source": "https://50ohm.de/E_mischer.html",
"confidence": 8
},
"EF204": {
"revision": 1,
"explanation": "A mixer gives sum and absolute difference: 145 MHz + 136 MHz = 281 MHz and |145 MHz - 136 MHz| = 9 MHz.",
"source": "https://50ohm.de/E_mischer.html",
"confidence": 8
},
"EF205": {
"revision": 1,
"explanation": "The wanted first-order mixer products are the sum and difference, here 281 MHz and 9 MHz.",
"source": "https://50ohm.de/E_mischer.html",
"confidence": 8
},
"EF206": {
"revision": 1,
"explanation": "Mixers generate many RF products, so good shielding is needed to keep unwanted signals from being radiated or coupled into other stages.",
"source": "https://50ohm.de/E_mischer.html",
"confidence": 8
},
"EF207": {
"revision": 1,
"explanation": "An oscillator should be enclosed in a grounded metal shield so its RF energy is not unintentionally radiated.",
"source": "https://50ohm.de/NE_oszillatoren.html",
"confidence": 8
},
"EF208": {
"revision": 1,
"explanation": "In direct conversion the IF is audio, so the local oscillator must be very close to the received RF frequency.",
"source": "https://50ohm.de/E_ueberlagerungsempfaenger_einfachsuper_1.html",
"confidence": 8
},
"EF209": {
"revision": 1,
"explanation": "A BFO inserts the missing carrier needed to demodulate CW or SSB, making those signals audible.",
"source": "https://50ohm.de/NEA_bfo_1.html",
"confidence": 8
},
"EF210": {
"revision": 1,
"explanation": "Narrow receiver bandwidth rejects nearby unwanted signals, which is exactly high selectivity.",
"source": "https://50ohm.de/E_trennschaerfe_1.html",
"confidence": 8
},
"EF211": {
"revision": 1,
"explanation": "AGC changes receiver gain as the RF input varies, keeping the demodulated audio level more constant.",
"source": "https://50ohm.de/NE_agc_1.html",
"confidence": 8
},
"EF212": {
"revision": 1,
"explanation": "AGC stands for Automatic Gain Control, the automatic receiver gain regulation used to reduce level swings.",
"source": "https://50ohm.de/NE_agc_1.html",
"confidence": 8
},
"EF213": {
"revision": 1,
"explanation": "Noise Reduction tries to distinguish wanted signal from noise and suppress the noise component in the received signal.",
"source": "https://50ohm.de/NE_noise_reduction.html",
"confidence": 8
},
"EF214": {
"revision": 1,
"explanation": "A noise blanker blanks short impulse disturbances, unlike a notch filter or AGC which target different problems.",
"source": "https://50ohm.de/NE_noise_reduction.html",
"confidence": 8
},
"EF215": {
"revision": 1,
"explanation": "A notch filter is a narrow rejection filter, so it can suppress interference at one small frequency range while leaving the rest mostly unchanged.",
"source": "https://50ohm.de/NE_notchfilter.html",
"confidence": 8
},
"EF216": {
"revision": 1,
"explanation": "A notch response is recognized by a narrow dip in an otherwise passed band; the correct diagram shows that sharp rejection notch.",
"source": "https://50ohm.de/NE_notchfilter.html",
"confidence": 7
},
"EF217": {
"revision": 1,
"explanation": "An attenuator reduces the RF input level before the receiver front end, preventing overload from strong signals.",
"source": "https://50ohm.de/NE_vorverstaerker_daempfungsglied.html",
"confidence": 8
},
"EF218": {
"revision": 1,
"explanation": "A UHF preamplifier should be at the antenna so it amplifies the signal before feed-line loss degrades the noise figure.",
"source": "https://50ohm.de/NE_vorverstaerker_daempfungsglied.html",
"confidence": 8
},
"EF219": {
"revision": 1,
"explanation": "A 9600-port bypasses audio filtering and takes receive data directly after the FM demodulator, which is point 4 in the shown chain.",
"source": "https://50ohm.de/NEA_9600_port.html",
"confidence": 7
},
"EF301": {
"revision": 1,
"explanation": "The multiplier chain is reversed by division: 145.2 MHz / 2 / 3 / 2 = 12.1 MHz.",
"source": "https://50ohm.de/NE_frequenzvervielfacher_1.html",
"confidence": 8
},
"EF302": {
"revision": 1,
"explanation": "Work backward through the multipliers in the diagram: 21.360 MHz / 3 / 2 = 3.560 MHz.",
"source": "https://50ohm.de/NE_frequenzvervielfacher_1.html",
"confidence": 8
},
"EF303": {
"revision": 1,
"explanation": "Work forward through the multiplier chain: 3.51 MHz x 2 x 2 = 14.04 MHz at output a.",
"source": "https://50ohm.de/NE_frequenzvervielfacher_1.html",
"confidence": 8
},
"EF304": {
"revision": 1,
"explanation": "Temperature changes alter oscillator L/C values gradually, so a VFO under changing temperature slowly drifts in frequency.",
"source": "https://50ohm.de/NE_oszillatoren.html",
"confidence": 8
},
"EF305": {
"revision": 1,
"explanation": "ALC protects the transmit chain from overdrive by reducing the signal amplitude before the power amplifier when level is too high.",
"source": "https://50ohm.de/NEA_alc.html",
"confidence": 8
},
"EF306": {
"revision": 2,
"explanation": "A dynamic compressor raises quiet speech parts relative to loud ones, compressing the speech dynamic range.",
"source": "https://50ohm.de/NE_slide_ne_modulation.html",
"confidence": 8
},
"EF307": {
"revision": 1,
"explanation": "A speech microphone amplifier should pass roughly 300 Hz to 3 kHz and reject lower and higher frequencies, matching the band-pass graph.",
"source": "https://50ohm.de/NE_verstaerker.html",
"confidence": 7
},
"EF308": {
"revision": 1,
"explanation": "Intelligible SSB speech needs only about 2.5 to 3 kHz of audio bandwidth, so about 2.5 kHz is the minimum matching answer.",
"source": "https://50ohm.de/NE_verstaerker.html",
"confidence": 8
},
"EF309": {
"revision": 1,
"explanation": "For 9600-baud FM data the signal should bypass speech audio filters and enter directly at the FM modulator, point 2 in the transmitter diagram.",
"source": "https://50ohm.de/NEA_9600_port.html",
"confidence": 7
},
"EF310": {
"revision": 1,
"explanation": "An SSB speech filter only needs the voice sideband width; practical SSB generation commonly uses about 2.4 kHz.",
"source": "https://50ohm.de/E_ssb_2.html",
"confidence": 8
},
"EF401": {
"revision": 1,
"explanation": "Transmitter output power is measured directly at the transmitter output before tuners, filters, feed lines, or other accessories change it.",
"source": "https://50ohm.de/E_senderausgangsleistung.html",
"confidence": 8
},
"EF402": {
"revision": 1,
"explanation": "For SSB the relevant PEP is measured at the transmitter output using a steady one- or two-tone drive, not with an unmodulated carrier at the antenna.",
"source": "https://50ohm.de/E_senderausgangsleistung.html",
"confidence": 8
},
"EF403": {
"revision": 1,
"explanation": "SSB carries information in signal amplitude and phase, so its final stage must be linear to avoid distorting the waveform.",
"source": "https://50ohm.de/EA_verstaerker.html",
"confidence": 8
},
"EF404": {
"revision": 1,
"explanation": "Changing the final amplifier bias can change linearity, so the transmitter must then be checked for harmonic output.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EF405": {
"revision": 1,
"explanation": "The transmitter supply should be well decoupled against RF so RF energy cannot couple into the power wiring or other stages.",
"source": "https://50ohm.de/EA_verstaerker.html",
"confidence": 8
},
"EF501": {
"revision": 1,
"explanation": "A transverter converts both directions: on receive it downconverts the higher band to the transceiver band, and on transmit it upconverts the transceiver signal.",
"source": "https://50ohm.de/NE_transverter_1.html",
"confidence": 8
},
"EF502": {
"revision": 1,
"explanation": "A transverter changes bands by mixing the input signal with a local oscillator and filtering the wanted product.",
"source": "https://50ohm.de/NE_transverter_1.html",
"confidence": 8
},
"EF503": {
"revision": 1,
"explanation": "The block diagram shows receive and transmit frequency conversion around a VHF transceiver, which is a transverter for the 2 m band.",
"source": "https://50ohm.de/NE_transverter_1.html",
"confidence": 7
},
"EF504": {
"revision": 1,
"explanation": "The diagram upconverts a VHF transmit signal to the 13 cm range, so it is a 13 cm converter placed before a VHF transmitter.",
"source": "https://50ohm.de/NE_transverter_1.html",
"confidence": 7
},
"EF505": {
"revision": 1,
"explanation": "In a GHz transverter the oscillator is multiplied, so any oscillator frequency error is multiplied too and can be too large for SSB satellite operation.",
"source": "https://50ohm.de/NE_transverter_1.html",
"confidence": 8
},
"EF601": {
"revision": 1,
"explanation": "Digital signal processing first converts the analog input with an A/D converter and later reconstructs an analog output with a D/A converter.",
"source": "https://50ohm.de/NEA_digitale_signalverarbeitung_einleitung.html",
"confidence": 8
},
"EF602": {
"revision": 1,
"explanation": "A digital filter can only process digital samples, so the analog input signal must first be digitized by A/D conversion.",
"source": "https://50ohm.de/NEA_digitale_signalverarbeitung_einleitung.html",
"confidence": 8
},
"EF603": {
"revision": 1,
"explanation": "SDR means Software Defined Radio: at least part of the receiver or transceiver signal processing is implemented in software.",
"source": "https://50ohm.de/NEA_digitale_signalverarbeitung_einleitung.html",
"confidence": 8
},
"EG101": {
"revision": 1,
"explanation": "A loop made from three equal wire sections forms a triangle, so it is the delta-loop form of a full-wave loop antenna.",
"source": "https://50ohm.de/EA_antennenformen_2.html",
"confidence": 8
},
"EG102": {
"revision": 1,
"explanation": "A wire antenna can have many lengths if an appropriate matching network is used; resonance and feed impedance change with length.",
"source": "https://50ohm.de/NE_antenne_laenge_resonanz.html",
"confidence": 8
},
"EG103": {
"revision": 1,
"explanation": "The diagram shows a wire fed from one end through a simple matching unit, which is an end-fed antenna with a basic matching network.",
"source": "https://50ohm.de/E_antennenformen_2.html",
"confidence": 7
},
"EG104": {
"revision": 1,
"explanation": "The shown end-fed wire with a tuned Fuchs matching circuit is the characteristic Fuchs antenna arrangement.",
"source": "https://50ohm.de/E_antennenformen_2.html",
"confidence": 7
},
"EG105": {
"revision": 1,
"explanation": "A magnetic loop is small compared with wavelength, about lambda/10 circumference, and its near field is dominated by a strong magnetic component.",
"source": "https://50ohm.de/EA_antennenformen_2.html",
"confidence": 8
},
"EG106": {
"revision": 1,
"explanation": "Common HF transmitting antennas include long wire, Yagi-Uda, dipole, Windom, and delta-loop; horn, patch, and parabolic antennas are mainly higher-frequency forms.",
"source": "https://50ohm.de/EA_antennenformen_2.html",
"confidence": 8
},
"EG107": {
"revision": 2,
"explanation": "For 80 m HF operation, dipoles, delta loops, and W3DZZ trap dipoles are practical wire antennas; parabolic, cross-Yagi, and trap-sleeve forms are not suitable choices here.",
"source": "https://50ohm.de/NE_slide_ne_antennen_uebertragungsleitungen.html",
"confidence": 8
},
"EG108": {
"revision": 1,
"explanation": "A 5/8-wave vertical is chosen because its length gives better antenna gain than a quarter-wave mobile vertical.",
"source": "https://50ohm.de/E_antennenformen_2.html",
"confidence": 8
},
"EG109": {
"revision": 1,
"explanation": "The wavelength is 300 / 28.5 = 10.53 m, and 5/8 of that is about 6.58 m.",
"source": "https://50ohm.de/NE_antenne_laenge_resonanz.html",
"confidence": 8
},
"EG110": {
"revision": 1,
"explanation": "A folded dipole is essentially a flattened full-wave loop, so the total wire length is one wavelength.",
"source": "https://50ohm.de/NE_antenne_laenge_resonanz.html",
"confidence": 8
},
"EG111": {
"revision": 1,
"explanation": "A simple Yagi-Uda has the longer reflector behind the driven element and a shorter director in front, giving the order reflector, driven element, director.",
"source": "https://50ohm.de/NE_yagi_uda_2.html",
"confidence": 7
},
"EG112": {
"revision": 2,
"explanation": "For a directional HF antenna, placing it high and far from neighboring equipment reduces field strength at the neighbor and therefore coupling risk.",
"source": "https://50ohm.de/NE_slide_ne_antennen_uebertragungsleitungen.html",
"confidence": 8
},
"EG113": {
"revision": 1,
"explanation": "Microwave dish antennas use a paraboloid reflector plus a feed antenna; the feed illuminates the reflector that forms the narrow beam.",
"source": "https://50ohm.de/EA_parabolspiegel_1.html",
"confidence": 8
},
"EG114": {
"revision": 1,
"explanation": "Dish gain improves when the reflector is many wavelengths across; at least about five wavelengths is the suitable choice for high gain.",
"source": "https://50ohm.de/EA_parabolspiegel_1.html",
"confidence": 8
},
"EG201": {
"revision": 1,
"explanation": "The shortening factor compares wave speed on the line or wire with wave speed in vacuum, so it is the velocity ratio.",
"source": "https://50ohm.de/E_verkuerzungsfaktor_1.html",
"confidence": 8
},
"EG202": {
"revision": 1,
"explanation": "For wire antennas the usual shortening correction is about 0.95, meaning about 95 percent of the free-space calculated length.",
"source": "https://50ohm.de/E_verkuerzungsfaktor_1.html",
"confidence": 8
},
"EG203": {
"revision": 1,
"explanation": "At a dipole end charge and voltage are high while current goes to zero, so the ends are voltage maxima and current nodes.",
"source": "https://50ohm.de/NEA_strom_spannung_speisung_1.html",
"confidence": 8
},
"EG204": {
"revision": 1,
"explanation": "Current feeding means high current and low voltage at the feed point, a current maximum and voltage node, which gives low impedance.",
"source": "https://50ohm.de/NE_strom_spannung_speisung_1.html",
"confidence": 8
},
"EG205": {
"revision": 1,
"explanation": "Voltage feeding is the opposite case: high voltage and nearly zero current at the feed point, so the feed point is high impedance.",
"source": "https://50ohm.de/NE_strom_spannung_speisung_1.html",
"confidence": 8
},
"EG206": {
"revision": 1,
"explanation": "A half-wave dipole fed in the middle has its current maximum at the center, so it is current-fed on its fundamental frequency.",
"source": "https://50ohm.de/NE_strom_spannung_speisung_1.html",
"confidence": 8
},
"EG207": {
"revision": 1,
"explanation": "A center-fed half-wave dipole high above ground has a free-space feed impedance near 73 Ohm, so the rounded answer is 75 Ohm.",
"source": "https://50ohm.de/E_fusspunktimpedanz_1.html",
"confidence": 8
},
"EG208": {
"revision": 1,
"explanation": "Ground interaction changes a center-fed half-wave dipole impedance with height, typically over about 40 to 90 Ohm.",
"source": "https://50ohm.de/E_fusspunktimpedanz_1.html",
"confidence": 8
},
"EG209": {
"revision": 1,
"explanation": "A straight center-fed half-wave dipole is in the same practical impedance range as the height-dependent value, about 40 to 90 Ohm.",
"source": "https://50ohm.de/E_fusspunktimpedanz_1.html",
"confidence": 8
},
"EG210": {
"revision": 1,
"explanation": "A folded dipole approximately quadruples the feed impedance of a normal dipole, giving about 240 to 300 Ohm.",
"source": "https://50ohm.de/E_fusspunktimpedanz_1.html",
"confidence": 8
},
"EG211": {
"revision": 1,
"explanation": "A ground-plane is roughly half a dipole against ground, and sloping radials bring its feed impedance into the 30 to 50 Ohm range.",
"source": "https://50ohm.de/E_fusspunktimpedanz_1.html",
"confidence": 8
},
"EG212": {
"revision": 1,
"explanation": "In a Yagi-Uda antenna the feed is applied to the driven element, called the Strahler; reflector and directors are parasitic elements.",
"source": "https://50ohm.de/NE_yagi_uda_2.html",
"confidence": 8
},
"EG213": {
"revision": 1,
"explanation": "A ground-plane is unbalanced because the radial side is at earth or counterpoise potential; dipoles, folded dipoles, and Yagis are balanced antenna forms.",
"source": "https://50ohm.de/EA_antennenformen_2.html",
"confidence": 8
},
"EG214": {
"revision": 1,
"explanation": "A half-wave dipole pattern has two equal broad lobes perpendicular to the wire, matching the symmetric two-lobed diagram.",
"source": "https://50ohm.de/NE_antennenformen_2.html",
"confidence": 7
},
"EG215": {
"revision": 1,
"explanation": "The shown two-lobed pattern perpendicular to the wire is the typical radiation pattern of a half-wave dipole.",
"source": "https://50ohm.de/NE_antennenformen_2.html",
"confidence": 7
},
"EG216": {
"revision": 1,
"explanation": "The nearly circular horizontal pattern around the vertical radiator is typical of a ground-plane antenna viewed from above.",
"source": "https://50ohm.de/EA_antennenformen_2.html",
"confidence": 7
},
"EG217": {
"revision": 1,
"explanation": "A large forward lobe with a smaller rear lobe indicates directional gain, so the diagram is for a directional antenna.",
"source": "https://50ohm.de/EA_antennenformen_2.html",
"confidence": 7
},
"EG218": {
"revision": 1,
"explanation": "A Yagi-Uda radiation pattern has a strong main lobe toward the directors and smaller rear or side lobes, matching the shown diagram.",
"source": "https://50ohm.de/NE_yagi_uda_2.html",
"confidence": 7
},
"EG219": {
"revision": 1,
"explanation": "A vertical half-wave antenna radiates mainly perpendicular to the vertical element, giving a low elevation or flat radiation angle.",
"source": "https://50ohm.de/E_antennenformen_2.html",
"confidence": 8
},
"EG220": {
"revision": 1,
"explanation": "The suffix dBi means gain in dB relative to an isotropic radiator, the ideal antenna radiating equally in all directions.",
"source": "https://50ohm.de/NE_antennengewinn.html",
"confidence": 8
},
"EG221": {
"revision": 1,
"explanation": "dBd is referenced to a half-wave dipole, which is 2.15 dB above isotropic; 5 dBd + 2.15 dB = 7.15 dBi.",
"source": "https://50ohm.de/NE_antennengewinn.html",
"confidence": 8
},
"EG222": {
"revision": 1,
"explanation": "Antenna polarization is defined by the electric field orientation in the main radiation direction relative to the earth surface.",
"source": "https://50ohm.de/E_polarisation_2.html",
"confidence": 8
},
"EG223": {
"revision": 2,
"explanation": "Putting the transmitting antenna outdoors reduces coupling into house wiring and nearby electrical installations.",
"source": "https://50ohm.de/NE_slide_ne_antennen_uebertragungsleitungen.html",
"confidence": 8
},
"EG301": {
"revision": 1,
"explanation": "A line's characteristic impedance is set by its conductor geometry and dielectric; in the HF range it is roughly constant and does not depend on the load connected at the end.",
"source": "https://50ohm.de/E_uebertragungsleitungen_2.html",
"confidence": 8
},
"EG302": {
"revision": 1,
"explanation": "Good coaxial cable confines the RF field inside the shield in normal use, reducing unwanted radiation between station devices.",
"source": "https://50ohm.de/E_uebertragungsleitungen_2.html",
"confidence": 8
},
"EG303": {
"revision": 1,
"explanation": "N connectors are designed for 50 Ohm operation into the GHz range and are suitable for higher power and voltage than SMA or BNC in this comparison.",
"source": "https://50ohm.de/E_uebertragungsleitungen_2.html",
"confidence": 8
},
"EG304": {
"revision": 1,
"explanation": "A feed line is unbalanced when the two conductors are not equivalent, as in coax where the inner conductor and shield have different shapes and potentials.",
"source": "https://50ohm.de/E_uebertragungsleitungen_2.html",
"confidence": 8
},
"EG305": {
"revision": 1,
"explanation": "Open parallel-wire feed line avoids much dielectric loss and can withstand high voltages better than coaxial cable.",
"source": "https://50ohm.de/E_uebertragungsleitungen_2.html",
"confidence": 8
},
"EG306": {
"revision": 1,
"explanation": "Running RF feed lines directly beside mains leads can couple RF into the power wiring, so a shared cable duct can worsen interference risk.",
"source": "https://50ohm.de/E_uebertragungsleitungen_2.html",
"confidence": 8
},
"EG307": {
"revision": 1,
"explanation": "Cable losses in dB are added as positive attenuation values; the shown station layout sums to 5 dB of cable loss.",
"source": "https://50ohm.de/EA_kabeldaempfung_1.html",
"confidence": 7
},
"EG308": {
"revision": 1,
"explanation": "With SWR 1 there is no reflection; 100 W reduced to 50 W is a factor of 2 loss, which corresponds to 3 dB attenuation.",
"source": "https://50ohm.de/EA_kabeldaempfung_1.html",
"confidence": 8
},
"EG309": {
"revision": 1,
"explanation": "Only one quarter of the power remains, so the loss factor is 4; a power factor of 4 is about 6 dB.",
"source": "https://50ohm.de/EA_kabeldaempfung_1.html",
"confidence": 8
},
"EG310": {
"revision": 1,
"explanation": "Only one tenth of the power remains, so the loss factor is 10; a power factor of 10 is 10 dB.",
"source": "https://50ohm.de/EA_kabeldaempfung_1.html",
"confidence": 8
},
"EG311": {
"revision": 1,
"explanation": "Cable attenuation scales with length for the same cable and frequency: 20 dB per 100 m times 20/100 gives 4 dB.",
"source": "https://50ohm.de/E_kabeldaempfung_1.html",
"confidence": 8
},
"EG312": {
"revision": 1,
"explanation": "The cable-loss chart gives RG58 at 145 MHz as about 20 dB per 100 m, and the question length is exactly 100 m.",
"source": "https://50ohm.de/E_kabeldaempfung_1.html",
"confidence": 8
},
"EG313": {
"revision": 1,
"explanation": "RG58 is about 20 dB per 100 m at 145 MHz; for 15 m the attenuation is 20 x 15/100 = 3 dB.",
"source": "https://50ohm.de/E_kabeldaempfung_1.html",
"confidence": 8
},
"EG314": {
"revision": 1,
"explanation": "The chart value for RG174 at 145 MHz is about 40 dB per 100 m; for 50 m this is 40 x 50/100 = 20 dB.",
"source": "https://50ohm.de/E_kabeldaempfung_1.html",
"confidence": 8
},
"EG315": {
"revision": 1,
"explanation": "The chart gives about 7 dB per 100 m for the 12.7 mm PE-foam cable at 435 MHz; 40 m gives 7 x 40/100 = 2.8 dB.",
"source": "https://50ohm.de/E_kabeldaempfung_1.html",
"confidence": 8
},
"EG316": {
"revision": 1,
"explanation": "The chart gives about 20.5 dB per 100 m for the 10.3 mm PE-foam cable at 1296 MHz; 40 m gives about 8.2 dB.",
"source": "https://50ohm.de/E_kabeldaempfung_1.html",
"confidence": 8
},
"EG401": {
"revision": 2,
"explanation": "For SWR 3 the reflection coefficient is (3 - 1)/(3 + 1) = 0.5, so reflected power is 0.5 squared = 25 percent of 100 W, i.e. 25 W.",
"source": "https://50ohm.de/NEA_swr.html",
"confidence": 8
},
"EG402": {
"revision": 2,
"explanation": "SWR 3 gives voltage reflection coefficient 0.5; power reflection is 0.5 squared, so 25 percent of forward power is reflected.",
"source": "https://50ohm.de/NEA_swr.html",
"confidence": 8
},
"EG403": {
"revision": 2,
"explanation": "If SWR 3 reflects 25 percent of the forward power, the remaining 75 percent is delivered to the load.",
"source": "https://50ohm.de/NEA_swr.html",
"confidence": 8
},
"EG404": {
"revision": 1,
"explanation": "The current on the outside of the coax shield is the common-mode or mantle current, called Mantelstrom in the diagram.",
"source": "https://50ohm.de/NE_mantelwellen_1.html",
"confidence": 7
},
"EG405": {
"revision": 1,
"explanation": "Mantle waves make the coax shield radiate or receive as part of the antenna, which can disturb other devices and worsen the station's own reception.",
"source": "https://50ohm.de/NE_mantelwellen_1.html",
"confidence": 8
},
"EG406": {
"revision": 1,
"explanation": "A balanced dipole fed directly with unbalanced coax can drive common-mode current on the shield, distorting the radiation pattern and creating mantle waves.",
"source": "https://50ohm.de/NE_mantelwellen_1.html",
"confidence": 8
},
"EG407": {
"revision": 2,
"explanation": "A balun connects a balanced antenna such as a dipole to an unbalanced feed line such as coax while suppressing common-mode current.",
"source": "https://50ohm.de/NE_mantelwellen_1.html",
"confidence": 8
},
"EG408": {
"revision": 2,
"explanation": "Coax turns on a ferrite core form a common-mode choke, increasing impedance for mantle currents and therefore damping mantle waves.",
"source": "https://50ohm.de/NE_mantelwellen_1.html",
"confidence": 7
},
"EG501": {
"revision": 2,
"explanation": "EIRP is antenna input power multiplied by antenna gain in the chosen direction, with the gain referenced to an isotropic radiator.",
"source": "https://life.itu.int/radioclub/rr/art1.pdf",
"confidence": 9
},
"EG502": {
"revision": 2,
"explanation": "First subtract losses from transmitter power to get power at the antenna, then multiply by antenna gain referenced to an isotropic radiator.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG503": {
"revision": 2,
"explanation": "26 dBi is a gain factor of about 10^2.6 = 398; 0.25 W times 398 is about 100 W EIRP.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG504": {
"revision": 2,
"explanation": "36 dBi is a gain factor of about 10^3.6 = 3981; 5 W times 3981 is about 20000 W EIRP.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG505": {
"revision": 2,
"explanation": "The net isotropic gain is 11 dBi - 1 dB = 10 dB, a factor of 10, so 100 W becomes 1000 W EIRP.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG506": {
"revision": 2,
"explanation": "A dipole has 2.15 dBi gain, factor 1.64, and the cable loss is also factor 1.64; they cancel, leaving 75 W EIRP.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG507": {
"revision": 2,
"explanation": "10 dB cable loss reduces 100 W to 10 W at the dipole; dipole gain is factor 1.64 relative to isotropic, giving 16.4 W EIRP.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG508": {
"revision": 2,
"explanation": "5 dBd equals 7.15 dBi; after 2 dB cable loss the net gain is 5.15 dB, factor about 3.28, so 5 W becomes 16.4 W EIRP.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG509": {
"revision": 2,
"explanation": "11 dBd equals 13.15 dBi; minus 1 dB cable loss gives 12.15 dB, factor about 16.4, and 0.6 W times that is about 9.8 W.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG510": {
"revision": 2,
"explanation": "0 dBd equals 2.15 dBi; after 1.5 dB cable loss the net gain is 0.65 dB, factor about 1.17, so 8.5 W becomes about 9.9 W.",
"source": "https://50ohm.de/NE_aequivalente_isotrope_strahlungsleistung_eirp_1.html",
"confidence": 8
},
"EG511": {
"revision": 1,
"explanation": "BEMFV notification starts at 10 W EIRP. A 5.15 dBi antenna has factor about 3.28, so transmitter power must be at most about 10 / 3.28 = 3 W.",
"source": "https://www.gesetze-im-internet.de/bemfv/__9.html",
"confidence": 9
},
"EH101": {
"revision": 1,
"explanation": "HF long-distance propagation uses sky waves refracted by ionized, electrically charged regions of the ionosphere.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH102": {
"revision": 1,
"explanation": "The important HF DX regions are mainly the F regions, which lie roughly from 130 km up to about 450 km altitude.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH103": {
"revision": 1,
"explanation": "The F2 region persists high in the ionosphere and is the main refracting region for long-distance HF communication.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH104": {
"revision": 1,
"explanation": "At night the D region absorption largely disappears, and 80 m DX is then mainly enabled by F2-region refraction.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH105": {
"revision": 1,
"explanation": "The D region is strongly ionized by daylight and absorbs lower HF, especially 80 m and 160 m, causing strong daytime attenuation.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH106": {
"revision": 1,
"explanation": "Sporadic-E occurs as unusually ionized patches in the E region and can support upper-HF to VHF propagation in summer.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH107": {
"revision": 1,
"explanation": "Solar activity follows the sunspot cycle, whose average period is about 11 years.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH201": {
"revision": 1,
"explanation": "The dead zone is between the end of ground-wave coverage and the first point where the sky wave returns to earth.",
"source": "https://50ohm.de/E_tote_zone_1.html",
"confidence": 8
},
"EH202": {
"revision": 1,
"explanation": "Where ground wave and sky wave overlap, phase differences can make the received field strength vary, producing fading.",
"source": "https://50ohm.de/NE_fading.html",
"confidence": 8
},
"EH203": {
"revision": 1,
"explanation": "Signal weakening from overlap and interference of ground and sky waves is called fading.",
"source": "https://50ohm.de/NE_fading.html",
"confidence": 8
},
"EH204": {
"revision": 1,
"explanation": "MUF means Maximum Usable Frequency, the highest frequency still refracted back for the wanted path.",
"source": "https://50ohm.de/NE_muf_luf_1.html",
"confidence": 8
},
"EH205": {
"revision": 1,
"explanation": "At sunspot maximum solar UV and X-ray output are high, increasing ionization especially in the F region.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH206": {
"revision": 1,
"explanation": "More free electrons in the F2 region allow higher frequencies to be refracted back, so the MUF rises.",
"source": "https://50ohm.de/NE_muf_luf_1.html",
"confidence": 8
},
"EH207": {
"revision": 1,
"explanation": "To use frequencies above the current MUF, the refracting region needs stronger ionization so it can bend those higher frequencies back.",
"source": "https://50ohm.de/NE_muf_luf_1.html",
"confidence": 8
},
"EH208": {
"revision": 1,
"explanation": "Skip distance depends strongly on takeoff angle: a flatter radiation angle produces a longer hop, while a steeper angle returns sooner.",
"source": "https://50ohm.de/E_sprungdistanz_1.html",
"confidence": 8
},
"EH209": {
"revision": 1,
"explanation": "LUF is limited mainly by absorption, and lower HF absorption is controlled by the ionization level of the D region.",
"source": "https://50ohm.de/NE_muf_luf_1.html",
"confidence": 8
},
"EH210": {
"revision": 1,
"explanation": "During the day the D region absorbs low HF strongly, so 160 m and 80 m sky-wave signals are weak for worldwide communication.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH211": {
"revision": 1,
"explanation": "On 160 m in daytime, D-region absorption prevents useful sky-wave propagation, so propagation is mainly by ground wave.",
"source": "https://50ohm.de/E_bodenwelle.html",
"confidence": 8
},
"EH212": {
"revision": 1,
"explanation": "HF ground waves follow the earth beyond the optical horizon, but their attenuation increases at higher frequencies.",
"source": "https://50ohm.de/E_bodenwelle.html",
"confidence": 8
},
"EH213": {
"revision": 1,
"explanation": "The greyline is the twilight zone near sunrise and sunset where D-region absorption is reduced while higher-layer refraction can remain useful.",
"source": "https://50ohm.de/NE_greyline.html",
"confidence": 8
},
"EH214": {
"revision": 1,
"explanation": "A solar flare can abruptly increase D-region ionization and absorb HF sky waves; this shortwave fadeout is the Moegel-Dellinger effect.",
"source": "https://50ohm.de/E_moegel_dellinger_effekt.html",
"confidence": 8
},
"EH215": {
"revision": 1,
"explanation": "The Moegel-Dellinger effect causes a temporary loss or severe impairment of HF sky-wave propagation.",
"source": "https://50ohm.de/E_moegel_dellinger_effekt.html",
"confidence": 8
},
"EH216": {
"revision": 1,
"explanation": "Long path means the signal travels in the direction opposite the shortest bearing to the other station, around the longer side of the earth.",
"source": "https://50ohm.de/EA_langer_kurzer_weg_1.html",
"confidence": 8
},
"EH217": {
"revision": 1,
"explanation": "For Germany to VK, long path points away from the direct route and reaches Australia via the opposite direction, over South America.",
"source": "https://50ohm.de/EA_langer_kurzer_weg_1.html",
"confidence": 8
},
"EH218": {
"revision": 1,
"explanation": "Short-skip paths under 1000 km on 10 m are produced by refraction in localized sporadic-E ionization patches.",
"source": "https://50ohm.de/NE_sporadic_e_2.html",
"confidence": 8
},
"EH219": {
"revision": 1,
"explanation": "At sunspot maximum the F region is strongly ionized, so the 10 m band can support worldwide daytime contacts even with low power.",
"source": "https://50ohm.de/E_ionosphaere_2.html",
"confidence": 8
},
"EH301": {
"revision": 1,
"explanation": "The troposphere is the lower atmospheric layer where weather processes occur.",
"source": "https://50ohm.de/NE_troposphaere_2.html",
"confidence": 8
},
"EH302": {
"revision": 1,
"explanation": "VHF/UHF over-horizon propagation can occur when waves are bent, reflected, or scattered by tropospheric regions with different temperature and density.",
"source": "https://50ohm.de/NE_troposphaere_2.html",
"confidence": 8
},
"EH303": {
"revision": 1,
"explanation": "VHF long-distance contacts mainly use tropospheric propagation effects rather than HF-style ionospheric sky-wave propagation.",
"source": "https://50ohm.de/NE_troposphaere_2.html",
"confidence": 8
},
"EH304": {
"revision": 1,
"explanation": "Sporadic-E is refraction by locally limited, unusually highly ionized regions inside the E layer.",
"source": "https://50ohm.de/NE_sporadic_e_2.html",
"confidence": 8
},
"EH305": {
"revision": 2,
"explanation": "Aurora makes CW tone quality rough and unstable, so the report uses R and S plus A for Aurora instead of a normal tone rating.",
"source": "https://50ohm.de/E_slide_e_wellenausbreitung.html",
"confidence": 8
},
"EI101": {
"revision": 1,
"explanation": "Voltage is measured across a component, so the meter is connected in parallel; high input resistance prevents the meter from loading the circuit.",
"source": "https://50ohm.de/E_strom_spannung_messung_2.html",
"confidence": 8
},
"EI102": {
"revision": 1,
"explanation": "To use Ohm's law for a resistor, current must be measured in series through it and voltage in parallel across it.",
"source": "https://50ohm.de/E_strom_spannung_messung_2.html",
"confidence": 7
},
"EI103": {
"revision": 1,
"explanation": "The pointer is at 29 percent of full scale; on the 10 V range that is 0.29 x 10 V = 2.9 V.",
"source": "https://50ohm.de/NEA_zeigerinstrumente_ablesen.html",
"confidence": 7
},
"EI104": {
"revision": 1,
"explanation": "On the 300 V range the same pointer position corresponds to about 29 percent of full scale, so 0.29 x 300 V is about 88 V.",
"source": "https://50ohm.de/NEA_zeigerinstrumente_ablesen.html",
"confidence": 7
},
"EI201": {
"revision": 1,
"explanation": "A VNA measures frequency-dependent impedance and reflection behavior, so it is suited to finding resonances and impedances of tuned circuits and antennas.",
"source": "https://50ohm.de/NEA_vna_1.html",
"confidence": 8
},
"EI202": {
"revision": 1,
"explanation": "Resonance can be calculated from measured L and C or found directly by sweeping the circuit with a VNA.",
"source": "https://50ohm.de/NEA_vna_1.html",
"confidence": 8
},
"EI203": {
"revision": 1,
"explanation": "A vector network analyzer directly measures complex impedance, including resistance, reactance, and reflection/SWR quantities.",
"source": "https://50ohm.de/NEA_vna_1.html",
"confidence": 8
},
"EI204": {
"revision": 1,
"explanation": "Impedance measurement is a core VNA use because it compares voltage/current or incident/reflected waves over frequency.",
"source": "https://50ohm.de/NEA_vna_1.html",
"confidence": 8
},
"EI205": {
"revision": 1,
"explanation": "A VNA must be calibrated with the measurement setup so its reference plane and systematic errors are corrected before use.",
"source": "https://50ohm.de/NEA_vna_1.html",
"confidence": 8
},
"EI206": {
"revision": 1,
"explanation": "Open and short should reflect almost all power, giving very high SWR, while a matched load should show SWR near 1.",
"source": "https://50ohm.de/NEA_vna_1.html",
"confidence": 8
},
"EI301": {
"revision": 2,
"explanation": "The displayed sine period spans 8 divisions; at 0.5 ms per division the period is 8 x 0.5 ms = 4 ms.",
"source": "https://50ohm.de/NE_oszilloskop_1.html",
"confidence": 7
},
"EI302": {
"revision": 2,
"explanation": "The period is 4 ms, so frequency is 1 / 0.004 s = 250 Hz.",
"source": "https://50ohm.de/NE_oszilloskop_1.html",
"confidence": 8
},
"EI303": {
"revision": 2,
"explanation": "Pulse duration is read from the middle of the rising edge to the middle of the falling edge; the shown interval is 200 microseconds.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 7
},
"EI304": {
"revision": 2,
"explanation": "Audio distortion changes the waveform shape, and an oscilloscope displays waveform shape directly.",
"source": "https://50ohm.de/E_slide_e_strom_spannung_widerstand_leistung_energie.html",
"confidence": 8
},
"EI401": {
"revision": 2,
"explanation": "An SWR meter measures the match between feed line and load, so in transmitter use it indicates antenna-system matching.",
"source": "https://50ohm.de/NE_slide_ne_antennen_uebertragungsleitungen.html",
"confidence": 8
},
"EI402": {
"revision": 2,
"explanation": "The instrument for showing the match between a UHF transmitter and its feed line is an SWR meter.",
"source": "https://50ohm.de/NE_slide_ne_antennen_uebertragungsleitungen.html",
"confidence": 8
},
"EI403": {
"revision": 2,
"explanation": "In transmit operation SWR is measured with an SWR bridge that compares forward and reflected power on the line.",
"source": "https://50ohm.de/NE_slide_ne_antennen_uebertragungsleitungen.html",
"confidence": 8
},
"EI404": {
"revision": 2,
"explanation": "To judge the antenna itself, the SWR meter should be as close to the antenna as possible, between antenna cable and antenna.",
"source": "https://50ohm.de/NE_slide_ne_antennen_uebertragungsleitungen.html",
"confidence": 8
},
"EI405": {
"revision": 2,
"explanation": "To check whether the whole antenna system is well matched to the transmitter, the SWR meter belongs at the transmitter output, point 1.",
"source": "https://50ohm.de/NE_slide_ne_antennen_uebertragungsleitungen.html",
"confidence": 7
},
"EI501": {
"revision": 1,
"explanation": "An unmodulated RF signal has a single stable frequency, which a frequency counter can count directly.",
"source": "https://50ohm.de/NE_frequenzmessung_1.html",
"confidence": 8
},
"EI502": {
"revision": 1,
"explanation": "The marked digit is in the 10^3 Hz position of the counter display, so its place value is one kilohertz.",
"source": "https://50ohm.de/NE_frequenzmessung_1.html",
"confidence": 7
},
"EI503": {
"revision": 1,
"explanation": "In this display the marked digit is in the 10 Hz position, so its place value is ten hertz.",
"source": "https://50ohm.de/NE_frequenzmessung_1.html",
"confidence": 7
},
"EI504": {
"revision": 1,
"explanation": "A 10:1 prescaler divides the input by 10 before counting, so the real frequency is 10 x 14.5625 MHz = 145.625 MHz.",
"source": "https://50ohm.de/NE_frequenzmessung_1.html",
"confidence": 8
},
"EJ101": {
"revision": 1,
"explanation": "Conducted RF interference enters equipment through attached leads such as mains, antenna, or speaker cables; that is Einströmung.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ102": {
"revision": 1,
"explanation": "Radiated RF entering through poor enclosure shielding is Einstrahlung, distinct from conducted entry via cables.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ103": {
"revision": 1,
"explanation": "Even a clean wanted signal can overload nearby receiver stages or otherwise influence them, so the issue is overload or disturbing influence, not spurious emission.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ104": {
"revision": 1,
"explanation": "Lower transmitter power lowers field strength and coupling risk, so use only the minimum needed for satisfactory communication.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ105": {
"revision": 1,
"explanation": "In dense residential areas during TV viewing hours, the practical interference-reduction step is to transmit with no more power than needed for reliable communication.",
"source": "https://50ohm.de/NE_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ106": {
"revision": 1,
"explanation": "A high-gain 432 MHz antenna pointed at a TV receive antenna can create a very strong local signal and overload the TV receiver input.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ107": {
"revision": 1,
"explanation": "Receiver overload drives input stages out of their normal range, reducing effective sensitivity or even blocking reception.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ108": {
"revision": 1,
"explanation": "A nearly closed metal enclosure provides RF shielding by enclosing the circuitry in a conductive shell.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ109": {
"revision": 1,
"explanation": "A parallel nearby HF antenna can inductively or capacitively couple RF current into the 230 V mains wiring.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ110": {
"revision": 1,
"explanation": "Running the 80 m wire at right angles to the row of houses avoids long parallel coupling to building wiring and neighboring installations.",
"source": "https://50ohm.de/E_standortwahl.html",
"confidence": 8
},
"EJ111": {
"revision": 1,
"explanation": "A separate RF earth for transmitting antennas helps keep RF currents out of house wiring and therefore lowers in-house interference risk.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ112": {
"revision": 1,
"explanation": "LED lamps with mains-connected electronics can be susceptible to RF influence, unlike simple thermal or motor loads in the alternatives.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ113": {
"revision": 1,
"explanation": "Strong RF can be rectified by nonlinear semiconductor junctions in an audio power stage, producing audible noise even when the stereo is nominally off.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ114": {
"revision": 1,
"explanation": "If RF is entering the audio power stage through speaker leads, shielding those leads reduces the conducted RF path.",
"source": "https://50ohm.de/E_slide_e_sender.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EJ115": {
"revision": 1,
"explanation": "A shielded intercom cable reduces RF pickup on the wiring that otherwise conducts the interfering signal into the door-phone electronics.",
"source": "https://50ohm.de/E_slide_e_sender.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EJ116": {
"revision": 1,
"explanation": "A DVB-T2 input should pass UHF TV frequencies while rejecting the much lower 28 MHz amateur signal, so a high-pass filter is appropriate.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ117": {
"revision": 1,
"explanation": "For HF interference in a TV antenna lead, use the high-pass filter: it rejects low HF while passing the higher TV bands.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 7
},
"EJ118": {
"revision": 1,
"explanation": "A mantle-wave choke raises impedance for common-mode RF on the outside of the coax shield, suppressing those RF interference currents.",
"source": "https://50ohm.de/E_slide_e_sender.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EJ119": {
"revision": 1,
"explanation": "If 144 MHz RF is induced as common-mode current on the broadcast receiver coax, a mantle-wave choke before the receiver reduces that current.",
"source": "https://50ohm.de/E_slide_e_sender.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EJ120": {
"revision": 1,
"explanation": "Intermodulation creates phantom signals from two or more strong signals; removing one participating signal removes the product.",
"source": "https://50ohm.de/E_slide_e_sender.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EJ121": {
"revision": 1,
"explanation": "Corroded metal contacts are nonlinear and can rectify or mix nearby transmitter signals, creating unwanted products that disturb TV reception.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ122": {
"revision": 1,
"explanation": "The first useful step is to check whether the disturbance actually coincides in time with your transmissions.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ123": {
"revision": 1,
"explanation": "A room antenna gives poor shielding and selectivity against strong local RF; an outdoor TV antenna improves wanted signal and allows better filtering.",
"source": "https://50ohm.de/E_slide_e_sender.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EJ124": {
"revision": 1,
"explanation": "After cooperative mitigation attempts fail, the proper next step is to ask the responsible Bundesnetzagentur field office to examine the situation.",
"source": "https://50ohm.de/E_stoerungen_elektronischer_geraete_1.html",
"confidence": 8
},
"EJ201": {
"revision": 1,
"explanation": "A pure sine wave contains only one frequency component; non-sinusoidal carriers contain harmonics that can cause interference.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ202": {
"revision": 1,
"explanation": "Harmonics are unwanted multiples of the wanted RF frequency, so an harmonic filter is used to reduce them.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ203": {
"revision": 1,
"explanation": "A low-pass filter passes the wanted fundamental output while attenuating higher-frequency harmonics.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ204": {
"revision": 1,
"explanation": "Between transmitter and antenna, a low-pass filter is best for reducing harmonic radiation above the operating frequency.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ205": {
"revision": 1,
"explanation": "A UHF transmitter's harmonics are at still higher frequencies, so a following low-pass filter attenuates them while passing the wanted UHF signal.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ206": {
"revision": 1,
"explanation": "The correct circuit is the low-pass output filter, with series inductors and shunt capacitors arranged to pass the fundamental and shunt harmonics.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 7
},
"EJ207": {
"revision": 1,
"explanation": "A harmonic-reduction filter should pass the HF operating range and roll off higher frequencies, i.e. a low-pass characteristic.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 7
},
"EJ208": {
"revision": 1,
"explanation": "For an HF multiband transmitter, the output filter should pass all HF bands while attenuating frequencies above them, so the wide low-pass curve is best.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 7
},
"EJ209": {
"revision": 1,
"explanation": "Unwanted-emission power is assessed at the transmitter output including normally used inline devices such as the SWR meter and any low-pass filter.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ210": {
"revision": 1,
"explanation": "Keeping SSB occupied bandwidth to at most about 2.7 kHz limits spillover onto adjacent frequencies.",
"source": "https://50ohm.de/E_ssb_2.html",
"confidence": 8
},
"EJ211": {
"revision": 1,
"explanation": "SSB speech audio above about 3 kHz would widen the RF sideband unnecessarily, increasing adjacent-channel interference risk.",
"source": "https://50ohm.de/E_ssb_2.html",
"confidence": 8
},
"EJ212": {
"revision": 1,
"explanation": "For FM AFSK, occupied bandwidth rises with frequency deviation, so lowering audio drive or deviation reduces the transmitted bandwidth.",
"source": "https://50ohm.de/EA_fm_2.html",
"confidence": 8
},
"EJ213": {
"revision": 1,
"explanation": "Overdriving a power amplifier makes it nonlinear, creating distortion products and a high level of unwanted emissions.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ214": {
"revision": 1,
"explanation": "An overdriven SSB linear amplifier produces intermodulation products that spread into neighboring frequencies.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ215": {
"revision": 1,
"explanation": "Too much microphone gain overdrives the SSB transmit chain and creates splatter affecting nearby stations.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ216": {
"revision": 1,
"explanation": "Poor frequency stability can make the transmitter drift, potentially moving the emission outside authorized band limits.",
"source": "https://50ohm.de/NE_unerwuenschte_aussendungen_2.html",
"confidence": 8
},
"EJ217": {
"revision": 1,
"explanation": "If ALC acts during SSB digital modes, it can distort the audio/RF envelope and create unwanted products on neighboring frequencies.",
"source": "https://50ohm.de/NEA_digimode_ssb.html",
"confidence": 8
},
"EJ218": {
"revision": 1,
"explanation": "The audio drive for FT8, JS8, PSK31, and similar modes should be low enough that ALC does not engage, avoiding distortion and splatter.",
"source": "https://50ohm.de/NEA_digimode_ssb.html",
"confidence": 8
},
"EJ219": {
"revision": 1,
"explanation": "If ALC is causing interference in SSB digital operation, reduce the audio input level so the transmitter is no longer driven into ALC action.",
"source": "https://50ohm.de/NEA_digimode_ssb.html",
"confidence": 8
},
"EK101": {
"revision": 1,
"explanation": "RF energy absorption in the human body depends on frequency, including penetration depth and resonance effects, so exposure limits are frequency-dependent.",
"source": "https://50ohm.de/E_personenschutzabstand_grenzwerte.html",
"confidence": 8
},
"EK102": {
"revision": 1,
"explanation": "The 26th BImSchV uses different time references: Annex 1b values are RMS-averaged over 6 minutes, Annex 1a values are short-term RMS values, and Annex 3 uses instantaneous peak limits for pulsed fields.",
"source": "https://www.gesetze-im-internet.de/bimschv_26/BJNR196600996.html",
"confidence": 9
},
"EK103": {
"revision": 1,
"explanation": "For active body aids, the relevant protection criterion is the maximum instantaneous field value, not a 3- or 6-minute average.",
"source": "https://50ohm.de/E_personenschutzabstand_grenzwerte.html",
"confidence": 8
},
"EK104": {
"revision": 1,
"explanation": "13 dBd is 15.15 dBi, a factor about 32.7; 6 W therefore gives about 196 W EIRP, well above the 10 W EIRP amateur-station threshold requiring proof/notification duties.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 9
},
"EK105": {
"revision": 1,
"explanation": "At 80 m the 3.65 m result lies in the reactive near field, where the far-field approximation is invalid, so measurement, simulation, or near-field calculation is needed.",
"source": "https://50ohm.de/E_naeherungsformel_1.html",
"confidence": 8
},
"EK106": {
"revision": 1,
"explanation": "The far-field approximation is invalid below roughly lambda/(2*pi); for 160 m this is about 25.5 m and for 80 m about 12.7 m.",
"source": "https://50ohm.de/E_naeherungsformel_1.html",
"confidence": 8
},
"EK107": {
"revision": 2,
"explanation": "When the safety distance is calculated from the antenna field, the distance must be maintained from every radiating point of the antenna, not only the feed point.",
"source": "https://50ohm.de/NEA_slide_nea_personenschutzabstand.html",
"confidence": 8
},
"EK108": {
"revision": 1,
"explanation": "Convert 7.5 dBd to 9.65 dBi, subtract 1.5 dB cable loss for 8.15 dB net gain, then use d = sqrt(30 x EIRP) / 28 V/m; the result is about 5.0 m.",
"source": "https://50ohm.de/E_naeherungsformel_1.html",
"confidence": 8
},
"EK201": {
"revision": 1,
"explanation": "Microwave antennas can concentrate high fields in a narrow beam, so people should not stay in the direct beam path of transmitting antennas.",
"source": "https://50ohm.de/NE_strahlengang_aufenthalt.html",
"confidence": 8
},
"EK202": {
"revision": 1,
"explanation": "Transmitting antennas can have high RF voltages on their conductors; touching them can cause burns and other RF voltage injuries.",
"source": "https://50ohm.de/E_slide_e_sicherheit.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EK203": {
"revision": 1,
"explanation": "Power-supply capacitors can remain charged after the mains plug is removed, so opening disconnected equipment can still expose you to electric shock.",
"source": "https://50ohm.de/NEA_slide_nea_sicherheit.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EK204": {
"revision": 1,
"explanation": "A fuse is a safety component matched to current and trip speed; after repair it must be replaced with the same current rating and same fast characteristic.",
"source": "https://50ohm.de/E_sicherungen.html",
"confidence": 8
},
"EK205": {
"revision": 1,
"explanation": "For a 3-core mains cable the standard colors are PE green-yellow, live conductor brown, and neutral blue.",
"source": "https://50ohm.de/E_spannungsquelle.html",
"confidence": 8
},
"EK206": {
"revision": 1,
"explanation": "Ungrounded wire antennas can accumulate static charge from weather such as rain or hail, creating a safety hazard.",
"source": "https://50ohm.de/E_slide_e_sicherheit.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EK207": {
"revision": 1,
"explanation": "High-value bleed resistors drain static charge to the station earth while their high resistance avoids significantly affecting RF operation.",
"source": "https://50ohm.de/NE_slide_ne_sicherheit.html?print-pdf=&showNotes=true",
"confidence": 8
},
"EK208": {
"revision": 1,
"explanation": "Bonding all antenna coax shields together and to the main earthing bar prevents dangerous potential differences between coax systems.",
"source": "https://50ohm.de/NE_slide_ne_sicherheit.html",
"confidence": 8
},
"EK209": {
"revision": 1,
"explanation": "The current Class E material states that an existing building earthing system may be used for antenna earthing, so no separate electrode or BNetzA approval is required for this answer.",
"source": "https://50ohm.de/NE_blitzerdung.html",
"confidence": 8
},
"EK210": {
"revision": 1,
"explanation": "VDE 0855-300 requires a solid earthing conductor, with example minimum cross sections of 16 mm2 copper, 25 mm2 aluminium, or 50 mm2 steel.",
"source": "https://50ohm.de/NE_blitzerdung.html",
"confidence": 8
},
"EK211": {
"revision": 1,
"explanation": "Connecting an antenna mast to an existing lightning protection system changes that system and must be included in the lightning protection concept by a qualified specialist.",
"source": "https://50ohm.de/NE_blitzerdung.html",
"confidence": 8
},
"NA101": {
"revision": 2,
"explanation": "Cutting at $2/3$ of 20 m gives a $13.33$ m piece; the remaining $1/3$ is $6.67$ m.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA102": {
"revision": 1,
"explanation": "The maximum count is the whole-number quotient: $250/18.5 = 13.5$, so only 13 complete antennas fit before the remaining wire is too short.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA103": {
"revision": 1,
"explanation": "Mass scales linearly with length for the same wire: $55/210$ of 100 m is about 26.2 m.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA201": {
"revision": 1,
"explanation": "Electric potential difference is measured in volts; amperes measure current, ohms resistance, and ampere-hours charge capacity.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA202": {
"revision": 1,
"explanation": "Electric current is the rate of flow of charge, and the SI unit for current is the ampere.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA203": {
"revision": 1,
"explanation": "Electrical resistance is measured in ohms, the unit that relates voltage and current through Ohm's law.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA204": {
"revision": 1,
"explanation": "Electrical power is measured in watts; joule is energy, kilowatt-hour is energy, and ampere-hour is charge capacity.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA205": {
"revision": 1,
"explanation": "Wavelength is a length, so it is normally expressed in metres rather than hertz or seconds.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA206": {
"revision": 1,
"explanation": "Frequency is cycles per second, and the named SI unit for that is hertz.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA207": {
"revision": 1,
"explanation": "One hertz means one cycle per second, so dimensionally $Hz = 1/s$.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA208": {
"revision": 1,
"explanation": "Milli means $10^{-3}$, so one volt is 1000 millivolts and 4.2 V is 4200 mV.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA209": {
"revision": 1,
"explanation": "Milli means $10^{-3}$; therefore 42 mA is $42/1000$ A, or 0.042 A.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA210": {
"revision": 1,
"explanation": "Milli means one thousandth, so one watt contains 1000 milliwatts.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA211": {
"revision": 2,
"explanation": "$0.010\\,\\mathrm{W} \\cdot 1000\\,\\mathrm{mW/W} = 10\\,\\mathrm{mW}$.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA212": {
"revision": 1,
"explanation": "Mega means $10^6$; $144000000$ Hz divided by $10^6$ is 144 MHz.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NA213": {
"revision": 1,
"explanation": "145000000 periods per second is 145000000 Hz, which is 145 MHz after dividing by $10^6$.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NB101": {
"revision": 2,
"explanation": "Among the listed metals, copper has the lowest resistivity at room temperature, so it has the highest conductivity in that group.",
"source": "https://50ohm.de/N_leiter_nichtleiter.html",
"confidence": 7
},
"NB102": {
"revision": 2,
"explanation": "Silver has even lower resistivity than copper, gold or tin at room temperature, so it is the best conductor in this list.",
"source": "https://50ohm.de/N_leiter_nichtleiter.html",
"confidence": 7
},
"NB103": {
"revision": 2,
"explanation": "Tin has higher resistivity than copper, gold and aluminium, so it is the poorest conductor among the listed metals.",
"source": "https://50ohm.de/N_leiter_nichtleiter.html",
"confidence": 7
},
"NB104": {
"revision": 2,
"explanation": "Porcelain and the plastics PE and PS are insulating materials; the other options include metals such as tungsten, brass or bronze.",
"source": "https://50ohm.de/N_leiter_nichtleiter.html",
"confidence": 7
},
"NB201": {
"revision": 1,
"explanation": "The alternating long and short parallel plates are the conventional schematic symbol for a battery or cell stack.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NB202": {
"revision": 1,
"explanation": "The shown reference symbol marks circuit ground or chassis reference, not an active source or switch.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NB203": {
"revision": 1,
"explanation": "In a battery symbol the longer plate denotes the positive terminal and the shorter plate denotes the negative terminal.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NB204": {
"revision": 2,
"explanation": "Series-connected cells add their voltages; six 1.5 V cells give $6 \\cdot 1.5 V = 9 V$.",
"source": "https://50ohm.de/N_batterien_und_akkus.html",
"confidence": 8
},
"NB205": {
"revision": 2,
"explanation": "The voltmeter is connected across two 1.5 V cells in series, so it reads their sum: 3 V.",
"source": "https://50ohm.de/N_spannungsmessung.html",
"confidence": 7
},
"NB206": {
"revision": 2,
"explanation": "Both meter leads are on points with the same potential in the shown circuit, so the potential difference is 0 V.",
"source": "https://50ohm.de/N_spannungsmessung.html",
"confidence": 7
},
"NB207": {
"revision": 2,
"explanation": "Current needs a complete closed loop through a source and load; the shown connection alone does not close a usable circuit.",
"source": "https://50ohm.de/N_slide_n_bauteile_und_schaltkreise.html",
"confidence": 7
},
"NB301": {
"revision": 1,
"explanation": "Electromagnetic waves in free space travel at the speed of light, about $3 \\cdot 10^8$ m/s or 300000 km/s.",
"source": "https://www.bipm.org/en/publications/si-brochure",
"confidence": 8
},
"NB302": {
"revision": 2,
"explanation": "Use $f = c/\\lambda$: $300000000 / 2.08$ is about 144 MHz.",
"source": "https://50ohm.de/N_wellenlaenge.html",
"confidence": 8
},
"NB303": {
"revision": 2,
"explanation": "Use $\\lambda = c/f$: $300000000 / 433500000$ is about 0.69 m.",
"source": "https://50ohm.de/N_wellenlaenge.html",
"confidence": 8
},
"NB304": {
"revision": 2,
"explanation": "Radio waves are transverse, so the receiving antenna should match the electric-field orientation; mismatched polarisation causes avoidable loss.",
"source": "https://50ohm.de/NEA_polarisation.html",
"confidence": 7
},
"NB401": {
"revision": 2,
"explanation": "A sinusoidal AC waveform is the smooth periodic curve with equal positive and negative half cycles shown in the correct figure.",
"source": "https://50ohm.de/N_sinusschwingung.html",
"confidence": 7
},
"NB402": {
"revision": 2,
"explanation": "Amplitude is the maximum displacement from the centre line; marker 1 points to that vertical height.",
"source": "https://50ohm.de/N_wellenlaenge.html",
"confidence": 7
},
"NB403": {
"revision": 2,
"explanation": "Wavelength is the spatial distance for one complete cycle, which is what marker 2 spans in the wave snapshot.",
"source": "https://50ohm.de/N_wellenlaenge.html",
"confidence": 7
},
"NB404": {
"revision": 2,
"explanation": "On an oscilloscope trace, amplitude is the vertical distance from the reference level to a peak; marker 1 indicates that height.",
"source": "https://50ohm.de/N_sinusschwingung.html",
"confidence": 7
},
"NB405": {
"revision": 2,
"explanation": "Period is the time for one complete cycle, so the horizontal interval marked 2 is one period.",
"source": "https://50ohm.de/N_sinusschwingung.html",
"confidence": 7
},
"NB501": {
"revision": 1,
"explanation": "Ohm's law relates voltage, current and resistance as $U = R \\cdot I$.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB502": {
"revision": 1,
"explanation": "Rearranging Ohm's law gives current as voltage divided by resistance: $I = U/R$.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB503": {
"revision": 1,
"explanation": "Rearranging $U = R \\cdot I$ for resistance gives $R = U/I$.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB504": {
"revision": 1,
"explanation": "Using Ohm's law with the shown resistance, $U = R \\cdot I$ gives 9.000 V for 90 mA.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB505": {
"revision": 1,
"explanation": "Resistance is found from $R = U/I$; applying the voltage and current shown in the figure gives 40 ohm.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 7
},
"NB601": {
"revision": 1,
"explanation": "DC input power is $P = U \\cdot I$, so $13.8 V \\cdot 1.5 A = 20.7 W$.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB602": {
"revision": 1,
"explanation": "Power converted to heat is $P = U \\cdot I$; 50 V times 0.050 A gives 2.5 W.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB603": {
"revision": 1,
"explanation": "20 mA is 0.020 A, and $3.2 V \\cdot 0.020 A = 0.064 W = 64.0 mW$.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB604": {
"revision": 1,
"explanation": "From $P = U \\cdot I$, current is $I = P/U = 100 W / 12 V = 8.33 A$.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB605": {
"revision": 1,
"explanation": "A 3 W load at 12 V draws $I = P/U = 3/12 = 0.25 A$, which is 250 mA.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB606": {
"revision": 1,
"explanation": "A 48 W load at 12 V draws $I = P/U = 48/12 = 4 A$.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 8
},
"NB701": {
"revision": 1,
"explanation": "The open contact in the shown schematic is the conventional symbol for a switch.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NB702": {
"revision": 1,
"explanation": "Technical current direction is defined from the positive terminal through the external circuit toward the negative terminal.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 7
},
"NB703": {
"revision": 2,
"explanation": "An LED lights only when the circuit is closed and the diode is forward-biased with current flowing through it.",
"source": "https://50ohm.de/N_slide_n_bauteile_und_schaltkreise.html",
"confidence": 7
},
"NC101": {
"revision": 1,
"explanation": "The zig-zag or rectangular two-terminal schematic element is the conventional resistor symbol.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NC102": {
"revision": 1,
"explanation": "In the resistor colour code, green as the multiplier band means $10^5$, or 100000.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC103": {
"revision": 1,
"explanation": "For 1.2 kOhm, the first two digits are 1 and 2, brown and red, and the multiplier is $10^2$, red.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC104": {
"revision": 1,
"explanation": "Red and violet give the digits 2 and 7; a red multiplier is $10^2$, so the value is $27 \\cdot 100 = 2700$ ohm, or 2.7 kOhm.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC105": {
"revision": 1,
"explanation": "Yellow and violet give 4 and 7; a red multiplier is $10^2$, so the value is 4700 ohm or 4.7 kOhm.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC106": {
"revision": 1,
"explanation": "Red and violet give 27; an orange multiplier is $10^3$, so the value is 27000 ohm or 27 kOhm.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC107": {
"revision": 1,
"explanation": "Yellow and violet give 47; an orange multiplier is $10^3$, so the value is 47000 ohm or 47 kOhm.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC108": {
"revision": 1,
"explanation": "In the resistor tolerance colour code, silver denotes a tolerance of plus or minus 10 percent.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC109": {
"revision": 1,
"explanation": "In the resistor tolerance colour code, gold denotes a tolerance of plus or minus 5 percent.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC110": {
"revision": 1,
"explanation": "In the resistor tolerance colour code, brown denotes a tolerance of plus or minus 1 percent.",
"source": "IEC 60062 marking codes for resistors and capacitors",
"confidence": 8
},
"NC201": {
"revision": 1,
"explanation": "Two separated plates in the schematic symbol represent a capacitor, because a capacitor stores charge between two conductors.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NC301": {
"revision": 1,
"explanation": "The looped or coiled schematic element is the conventional symbol for an inductor or coil.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NC401": {
"revision": 1,
"explanation": "A diode symbol shows a one-way junction; current flows conventionally from anode toward cathode when forward-biased.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NC402": {
"revision": 1,
"explanation": "A light-emitting diode is drawn as a diode with arrows showing emitted light.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NC403": {
"revision": 1,
"explanation": "The diode terminal at the triangle side is the anode, and the terminal at the bar side is the cathode.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NC404": {
"revision": 2,
"explanation": "Current flows through a diode circuit only when the diode is forward-biased and the loop is closed.",
"source": "https://50ohm.de/N_slide_n_bauteile_und_schaltkreise.html",
"confidence": 7
},
"NC501": {
"revision": 1,
"explanation": "A transistor symbol has three terminals for controlling current through the device, unlike two-terminal passive components.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"ND101": {
"revision": 2,
"explanation": "A mains power supply converts 230 V AC from the wall outlet into the DC voltage a mobile transceiver needs.",
"source": "https://50ohm.de/N_netzgeraet_1.html",
"confidence": 7
},
"ND102": {
"revision": 3,
"explanation": "Mobile amateur transceivers are normally designed for vehicle electrical systems, so an external supply is usually around 13.8 V DC.",
"source": "https://50ohm.de/N_netzgeraet_1.html",
"confidence": 7
},
"ND103": {
"revision": 2,
"explanation": "A complete DC circuit needs an outgoing and a return conductor, so current leaves through one lead and returns through the other.",
"source": "https://50ohm.de/N_netzgeraet_1.html",
"confidence": 7
},
"ND104": {
"revision": 2,
"explanation": "The two conductors complete the current path through the transceiver; without the return lead the circuit is open.",
"source": "https://50ohm.de/N_netzgeraet_1.html",
"confidence": 7
},
"ND105": {
"revision": 3,
"explanation": "DC equipment conventionally marks the positive lead red and the negative lead black to reduce polarity mistakes.",
"source": "https://50ohm.de/N_netzgeraet_1.html",
"confidence": 7
},
"ND106": {
"revision": 3,
"explanation": "Transceivers are polarity-sensitive DC loads, so reversing plus and minus can put voltage on the wrong internal circuitry.",
"source": "https://50ohm.de/N_netzgeraet_1.html",
"confidence": 7
},
"ND107": {
"revision": 3,
"explanation": "Reverse polarity can drive current through protection parts or semiconductor junctions in the wrong direction and damage the radio.",
"source": "https://50ohm.de/N_netzgeraet_1.html",
"confidence": 7
},
"ND108": {
"revision": 3,
"explanation": "Current limiting protects against short circuits, and thermal shutdown protects the supply when internal heating becomes excessive.",
"source": "https://50ohm.de/N_netzgeraet_1.html",
"confidence": 7
},
"ND109": {
"revision": 2,
"explanation": "The protective contact connects exposed conductive parts to the protective-earth conductor so fault current can be carried safely away.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 8
},
"ND110": {
"revision": 2,
"explanation": "A short circuit can make batteries or accumulators deliver very high current, causing heat, fire risk or cell damage.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 7
},
"ND201": {
"revision": 1,
"explanation": "An oscillator is a circuit that generates a periodic electrical signal without needing an external signal of that frequency.",
"source": "IEC 60050 International Electrotechnical Vocabulary",
"confidence": 7
},
"NE101": {
"revision": 2,
"explanation": "Modulation varies a carrier in a controlled way so information can be transported by the radio-frequency signal.",
"source": "https://50ohm.de/N_rauch_und_morsezeichen.html",
"confidence": 7
},
"NE102": {
"revision": 2,
"explanation": "SSB, FM and AM are all modulation methods; the distractors mix in bands, equipment names or operating procedures.",
"source": "https://50ohm.de/NE_trxmodulation.html",
"confidence": 7
},
"NE201": {
"revision": 2,
"explanation": "CW conveys information by keying a continuous RF carrier on and off, which forms the Morse elements.",
"source": "https://50ohm.de/N_rauch_und_morsezeichen.html",
"confidence": 7
},
"NE202": {
"revision": 2,
"explanation": "In amplitude modulation, the carrier amplitude follows the information signal while the carrier frequency ideally stays fixed.",
"source": "https://50ohm.de/NE_am.html",
"confidence": 7
},
"NE203": {
"revision": 2,
"explanation": "Ordinary AM transmits a carrier plus both sidebands; SSB suppresses the carrier and one sideband to save bandwidth and power.",
"source": "https://50ohm.de/NE_ssb.html",
"confidence": 7
},
"NE204": {
"revision": 2,
"explanation": "LSB and USB are the lower and upper sideband versions of SSB; both suppress the carrier but keep opposite sides of the spectrum.",
"source": "https://50ohm.de/NE_ssb.html",
"confidence": 7
},
"NE205": {
"revision": 2,
"explanation": "In an AM spectrum, the lower sideband lies below the carrier and the upper sideband lies above it.",
"source": "https://50ohm.de/NE_ssb.html",
"confidence": 7
},
"NE206": {
"revision": 2,
"explanation": "AM produces two mirror sidebands around the carrier, so the correct spectrum contains both LSB and USB for the audio content.",
"source": "https://50ohm.de/NE_am.html",
"confidence": 7
},
"NE207": {
"revision": 2,
"explanation": "USB keeps the sideband above the carrier, with audio-frequency components translated upward in frequency.",
"source": "https://50ohm.de/NE_ssb.html",
"confidence": 7
},
"NE208": {
"revision": 2,
"explanation": "LSB keeps the sideband below the carrier, so the audio spectrum appears on the lower-frequency side.",
"source": "https://50ohm.de/NE_ssb.html",
"confidence": 7
},
"NE209": {
"revision": 2,
"explanation": "USB is the upper-sideband mode of SSB, meaning the receiver demodulates only the sideband above the suppressed carrier frequency.",
"source": "https://50ohm.de/NE_trxmodulation.html",
"confidence": 7
},
"NE210": {
"revision": 2,
"explanation": "The 2 m amateur SSB convention uses upper sideband, so the transceiver mode must be USB.",
"source": "https://50ohm.de/NE_trxmodulation.html",
"confidence": 7
},
"NE211": {
"revision": 2,
"explanation": "On 80 m, amateur SSB voice conventionally uses lower sideband, so the receiver mode is LSB.",
"source": "https://50ohm.de/NE_trxmodulation.html",
"confidence": 7
},
"NE212": {
"revision": 2,
"explanation": "SSB speech depends on the correct sideband and precise tuning; checking sideband mode and tuning the VFO addresses both causes.",
"source": "https://50ohm.de/NE_trxmodulation.html",
"confidence": 7
},
"NE301": {
"revision": 2,
"explanation": "In frequency modulation, the information signal varies the carrier frequency while the carrier amplitude ideally remains constant.",
"source": "https://50ohm.de/NEA_fm.html",
"confidence": 7
},
"NE302": {
"revision": 2,
"explanation": "FM is defined by varying a carrier's frequency according to the signal being transmitted.",
"source": "https://50ohm.de/NEA_fm.html",
"confidence": 7
},
"NE303": {
"revision": 2,
"explanation": "FM information is carried by frequency deviation, so the RF amplitude is ideally unaffected by microphone audio.",
"source": "https://50ohm.de/NEA_fm.html",
"confidence": 7
},
"NE304": {
"revision": 2,
"explanation": "In ideal FM the transmitter output power is essentially constant; speaking louder changes deviation, not the set RF power.",
"source": "https://50ohm.de/NEA_fm.html",
"confidence": 7
},
"NE305": {
"revision": 2,
"explanation": "A 15 kHz-wide emission extends about half its bandwidth on each side of the centre frequency, so it needs at least 7.5 kHz clearance.",
"source": "https://50ohm.de/NE_bandbreite.html",
"confidence": 7
},
"NE306": {
"revision": 2,
"explanation": "Too much FM deviation usually comes from excessive audio level, so speaking more quietly reduces the modulation hub.",
"source": "https://50ohm.de/NEA_fm.html",
"confidence": 7
},
"NE307": {
"revision": 2,
"explanation": "Handheld VHF/UHF amateur radios commonly support analogue FM and digital voice systems such as DMR and D-STAR.",
"source": "https://50ohm.de/N_digital_voice.html",
"confidence": 7
},
"NE308": {
"revision": 2,
"explanation": "Voice repeaters on VHF/UHF commonly carry analogue FM and digital voice modes such as DMR and D-STAR.",
"source": "https://50ohm.de/N_relaisfunkstellen.html",
"confidence": 7
},
"NE309": {
"revision": 2,
"explanation": "Analogue amateur voice repeaters on VHF/UHF conventionally use FM because it is robust for local line-of-sight voice links.",
"source": "https://50ohm.de/N_relaisfunkstellen.html",
"confidence": 7
},
"NE310": {
"revision": 2,
"explanation": "An FM receiver cannot cleanly demodulate two equal-strength co-channel signals at once, so simultaneous relay input signals interfere badly.",
"source": "https://50ohm.de/N_relaisfunkstellen.html",
"confidence": 7
},
"NE401": {
"revision": 2,
"explanation": "Digital text modes only interoperate when both stations use the same waveform and parameters such as speed, tone spacing or protocol settings.",
"source": "https://50ohm.de/N_funkfernschreiben.html",
"confidence": 7
},
"NE402": {
"revision": 2,
"explanation": "Digital voice repeater networks need more than frequency and mode; routing parameters such as reflector, time slot or colour code select the intended network path.",
"source": "https://50ohm.de/N_digital_voice.html",
"confidence": 7
},
"NE403": {
"revision": 2,
"explanation": "Time-division systems carry separate conversations in alternating time slots, allowing more than one channel on the same RF frequency.",
"source": "https://50ohm.de/N_digital_voice.html",
"confidence": 7
},
"NE404": {
"revision": 2,
"explanation": "DMR, D-STAR, C4FM, M17 and FreeDV are amateur digital voice systems, unlike analogue-only or non-voice modes.",
"source": "https://50ohm.de/N_digital_voice.html",
"confidence": 7
},
"NE405": {
"revision": 2,
"explanation": "Link paths are fixed radio links used as infrastructure, for example to connect repeaters with each other or to HAMNET nodes.",
"source": "https://50ohm.de/N_slide_n_amateurfunkstationen.html",
"confidence": 7
},
"NF101": {
"revision": 2,
"explanation": "SWR indication reports the antenna matching condition during transmit, so display item 1 is the SWR meter.",
"source": "https://50ohm.de/N_swr.html",
"confidence": 7
},
"NF102": {
"revision": 2,
"explanation": "In transmit mode, a power meter display shows the RF output power being delivered by the transceiver.",
"source": "https://50ohm.de/N_ausgangsleistung.html",
"confidence": 7
},
"NF103": {
"revision": 2,
"explanation": "An S-meter indicates received signal strength, so it is the relevant receive-level display.",
"source": "https://50ohm.de/N_slide_n_erste_schritte.html",
"confidence": 7
},
"NF104": {
"revision": 2,
"explanation": "An amplitude spectrum shows signal strength versus frequency, which matches display item 3.",
"source": "https://50ohm.de/N_wasserfall.html",
"confidence": 7
},
"NF105": {
"revision": 2,
"explanation": "A waterfall diagram adds time to the spectrum display, with newer signal traces appearing as coloured or bright lines.",
"source": "https://50ohm.de/N_wasserfall.html",
"confidence": 7
},
"NF106": {
"revision": 2,
"explanation": "A waterfall plot uses one axis for frequency, one for time, and colour or brightness for received signal strength.",
"source": "https://50ohm.de/N_wasserfall.html",
"confidence": 7
},
"NF107": {
"revision": 2,
"explanation": "A mismatched or missing load reflects RF power back toward the transmitter, which can overheat or damage the final amplifier.",
"source": "https://50ohm.de/N_dummy_load_1.html",
"confidence": 7
},
"NF108": {
"revision": 2,
"explanation": "PTT means push-to-talk: pressing the microphone switch keys the transmitter.",
"source": "https://50ohm.de/N_erste_schritte.html",
"confidence": 7
},
"NF109": {
"revision": 2,
"explanation": "VOX is voice-operated transmit control, where microphone audio automatically keys the transmitter.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF110": {
"revision": 2,
"explanation": "If VOX is enabled, room noise or microphone audio can key the transmitter without pressing PTT.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF111": {
"revision": 2,
"explanation": "RIT changes only the receive frequency, letting you clarify the other station without moving your transmit frequency.",
"source": "https://50ohm.de/NE_rit.html",
"confidence": 7
},
"NF112": {
"revision": 2,
"explanation": "With RIT active, receive and transmit can be offset; the operator may tune reception while transmitting on a slightly different frequency.",
"source": "https://50ohm.de/NE_rit.html",
"confidence": 7
},
"NF113": {
"revision": 2,
"explanation": "Using different uplink and downlink bands makes filtering easier because the satellite can separate its receiver and transmitter signals more effectively.",
"source": "https://50ohm.de/N_slide_n_amateurfunkstationen.html",
"confidence": 7
},
"NF114": {
"revision": 2,
"explanation": "Digital modes need baseband audio or data between computer and radio, either by an audio/USB interface or by a modem that performs that conversion.",
"source": "https://50ohm.de/NE_computersteuerung.html",
"confidence": 7
},
"NF115": {
"revision": 2,
"explanation": "A data connector bypasses audio shaping intended for speech, giving digital signals a cleaner path into or out of the FM transceiver.",
"source": "https://50ohm.de/NE_computersteuerung.html",
"confidence": 7
},
"NF116": {
"revision": 2,
"explanation": "CAT control is a serial command interface used to read and set radio functions such as frequency, power and PTT from a computer.",
"source": "https://50ohm.de/NE_computersteuerung.html",
"confidence": 7
},
"NF117": {
"revision": 2,
"explanation": "Computer control can assert PTT or change settings unexpectedly, so it can create unintended transmissions or safety hazards if not supervised.",
"source": "https://50ohm.de/NE_computersteuerung.html",
"confidence": 7
},
"NF118": {
"revision": 2,
"explanation": "A digipeater is a digital relay: it receives packet data and retransmits it, possibly after updating fields such as routing information.",
"source": "https://50ohm.de/N_slide_n_amateurfunkstationen.html",
"confidence": 7
},
"NF201": {
"revision": 2,
"explanation": "The block diagram is a receiver because the signal path runs from antenna input through receiving stages toward audio or data output.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF301": {
"revision": 2,
"explanation": "The S-meter gives the operator a relative indication of received signal level.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF302": {
"revision": 2,
"explanation": "Squelch mutes the receiver audio until a signal exceeds the set threshold, hiding FM noise when no useful signal is present.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF303": {
"revision": 2,
"explanation": "Receiver sensitivity describes how weak a signal the receiver can still detect or demodulate usefully.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF401": {
"revision": 2,
"explanation": "The block diagram is a transmitter because the signal path builds an RF signal and delivers it toward the antenna output.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF402": {
"revision": 2,
"explanation": "A simple transmitter generates RF, combines it with modulation, filters unwanted products, and amplifies the wanted signal.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF403": {
"revision": 2,
"explanation": "The stages follow the usual transmitter chain: audio amplification, mixing with an RF oscillator, filtering, RF amplification, and final filtering.",
"source": "https://50ohm.de/N_slide_n_transceiver.html",
"confidence": 7
},
"NF404": {
"revision": 2,
"explanation": "A transmitter output filter should pass the wanted VHF band while attenuating unwanted frequencies outside it.",
"source": "https://50ohm.de/NE_slide_ne_sender.html",
"confidence": 7
},
"NG101": {
"revision": 1,
"explanation": "The shown schematic symbol represents an antenna connection, the point where RF energy is radiated or received.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NG102": {
"revision": 1,
"explanation": "The ground symbol marks an earth connection or earth reference in the antenna diagram.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NG103": {
"revision": 2,
"explanation": "A dipole has two arms fed near the centre, which is the configuration shown.",
"source": "https://50ohm.de/N_dipol.html",
"confidence": 7
},
"NG104": {
"revision": 2,
"explanation": "A Marconi antenna is a quarter-wave vertical worked against earth or a counterpoise, so it is a $\\lambda/4$ vertical antenna.",
"source": "https://50ohm.de/N_rundstrahler.html",
"confidence": 7
},
"NG105": {
"revision": 2,
"explanation": "A ground-plane antenna is a vertical radiator with radial conductors forming the counterpoise, matching the shown structure.",
"source": "https://50ohm.de/N_rundstrahler.html",
"confidence": 7
},
"NG106": {
"revision": 2,
"explanation": "The conductors that provide the counterpoise for a ground-plane antenna are called radials.",
"source": "https://50ohm.de/N_rundstrahler.html",
"confidence": 7
},
"NG107": {
"revision": 2,
"explanation": "An end-fed antenna is fed at one end rather than at the centre, which matches the depicted arrangement.",
"source": "https://50ohm.de/N_endgespeiste_antennen.html",
"confidence": 7
},
"NG108": {
"revision": 2,
"explanation": "A Yagi-Uda antenna uses a driven element with parasitic reflector and director elements on a boom, matching the shown directional antenna.",
"source": "https://50ohm.de/N_yagi_uda_1.html",
"confidence": 7
},
"NG109": {
"revision": 2,
"explanation": "Long-wire antennas are practical mainly on HF; at VHF/UHF their physical size and radiation behaviour make other antenna types usual.",
"source": "https://50ohm.de/N_endgespeiste_antennen.html",
"confidence": 7
},
"NG110": {
"revision": 2,
"explanation": "For a local round with stations in several directions, an omnidirectional antenna avoids aiming a directional beam at each station.",
"source": "https://50ohm.de/N_rundstrahler.html",
"confidence": 7
},
"NG111": {
"revision": 2,
"explanation": "Repeaters around the station may lie in many directions, so a roof-mounted omnidirectional antenna gives broad azimuth coverage and height.",
"source": "https://50ohm.de/N_rundstrahler.html",
"confidence": 7
},
"NG201": {
"revision": 2,
"explanation": "Common coaxial cable impedances include 50 ohm for transmitting systems and 75 ohm for receiving or video systems; 60 ohm also exists historically.",
"source": "https://50ohm.de/N_uebertragungsleitungen.html",
"confidence": 7
},
"NG202": {
"revision": 2,
"explanation": "The connector shown has the form used by the PL or UHF connector family.",
"source": "IEC 61169 radio-frequency connector series",
"confidence": 6
},
"NG203": {
"revision": 2,
"explanation": "The bayonet-lock form shown is characteristic of a BNC connector.",
"source": "IEC 61169 radio-frequency connector series",
"confidence": 6
},
"NG204": {
"revision": 2,
"explanation": "The threaded RF connector shown is the N connector, widely used at VHF/UHF for lower loss and better impedance control.",
"source": "IEC 61169 radio-frequency connector series",
"confidence": 6
},
"NG205": {
"revision": 2,
"explanation": "The small threaded connector shown is SMA, a compact RF connector commonly used on handhelds and microwave gear.",
"source": "IEC 61169 radio-frequency connector series",
"confidence": 6
},
"NG206": {
"revision": 2,
"explanation": "N and SMA connectors maintain better RF performance above 300 MHz than older connector systems such as PL.",
"source": "IEC 61169 radio-frequency connector series",
"confidence": 7
},
"NG207": {
"revision": 2,
"explanation": "Coaxial-line attenuation accumulates with length and generally rises with frequency, so both matter when choosing VHF/UHF feed line.",
"source": "https://50ohm.de/N_uebertragungsleitungen.html",
"confidence": 7
},
"NG208": {
"revision": 2,
"explanation": "Extra coax adds loss in both forward and reflected waves, so the meter can show a lower SWR even though efficiency has worsened.",
"source": "https://50ohm.de/N_swr.html",
"confidence": 7
},
"NG301": {
"revision": 2,
"explanation": "An SWR of 1:1 means no reflected power from mismatch, which is the best possible match.",
"source": "https://50ohm.de/N_swr.html",
"confidence": 8
},
"NG302": {
"revision": 2,
"explanation": "A high SWR-meter indication means significant reflected power, which points to poor antenna or feed-line matching.",
"source": "https://50ohm.de/N_swr.html",
"confidence": 7
},
"NG303": {
"revision": 2,
"explanation": "Mismatch or damage changes the line impedance seen by the transmitter, causing RF reflections and therefore a higher SWR.",
"source": "https://50ohm.de/N_swr.html",
"confidence": 7
},
"NG304": {
"revision": 2,
"explanation": "A dipole that resonates too low is electrically too long; shortening both arms raises its resonant frequency.",
"source": "https://50ohm.de/N_slide_n_antennen_und_leitungen.html",
"confidence": 8
},
"NG305": {
"revision": 2,
"explanation": "A dipole that resonates too high is electrically too short; lengthening both arms lowers its resonant frequency.",
"source": "https://50ohm.de/N_slide_n_antennen_und_leitungen.html",
"confidence": 8
},
"NG401": {
"revision": 2,
"explanation": "ERP is radiated power referenced to a half-wave dipole, not to an isotropic radiator.",
"source": "https://life.itu.int/radioclub/rr/art1.pdf",
"confidence": 8
},
"NG402": {
"revision": 2,
"explanation": "EIRP is radiated power referenced to an ideal isotropic radiator.",
"source": "https://life.itu.int/radioclub/rr/art1.pdf",
"confidence": 8
},
"NH101": {
"revision": 2,
"explanation": "The ionosphere is the ionised upper-atmosphere region that can refract HF radio waves back toward Earth.",
"source": "https://50ohm.de/NEA_ionosphaere.html",
"confidence": 7
},
"NH102": {
"revision": 2,
"explanation": "Free electrons and ions in the ionosphere change the refractive index for radio waves, allowing HF waves to bend rather than travel straight into space.",
"source": "https://50ohm.de/NEA_ionosphaere.html",
"confidence": 7
},
"NH201": {
"revision": 2,
"explanation": "Solar activity controls ionisation density in the ionosphere, and the roughly eleven-year solar cycle therefore strongly affects HF propagation.",
"source": "https://50ohm.de/NEA_ionosphaere.html",
"confidence": 7
},
"NH301": {
"revision": 2,
"explanation": "Standard atmospheric refraction bends VHF paths slightly toward Earth, making the radio horizon about 15 percent beyond the geometric horizon.",
"source": "https://50ohm.de/N_funkhorizont.html",
"confidence": 7
},
"NH302": {
"revision": 2,
"explanation": "VHF coverage is largely line-of-sight; raising the antenna increases the visible radio path over terrain and curvature.",
"source": "https://50ohm.de/N_funkhorizont.html",
"confidence": 7
},
"NH303": {
"revision": 2,
"explanation": "The best VHF path is the station with the clearest quasi-optical path in the terrain profile; in the shown figure that is $\\text{E}_3$.",
"source": "https://50ohm.de/N_funkhorizont.html",
"confidence": 7
},
"NH304": {
"revision": 2,
"explanation": "Tropospheric inversions can form ducts or enhanced refractive layers, allowing VHF signals to travel hundreds of kilometres beyond normal range.",
"source": "https://50ohm.de/N_troposphaere.html",
"confidence": 7
},
"NH305": {
"revision": 2,
"explanation": "Sporadic-E uses dense temporary ionisation patches in the E region, typically around 100 to 110 km altitude.",
"source": "https://50ohm.de/NEA_sporadic_e_1.html",
"confidence": 7
},
"NH306": {
"revision": 2,
"explanation": "On 2 m, Sporadic-E means unusually long VHF paths via refraction in sporadic E-region ionisation, often around 1000 to 2000 km.",
"source": "https://50ohm.de/NEA_sporadic_e_1.html",
"confidence": 7
},
"NI101": {
"revision": 1,
"explanation": "The voltmeter symbol identifies a voltage-measuring instrument, which is connected across the points whose potential difference is measured.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NI102": {
"revision": 1,
"explanation": "The ammeter symbol identifies a current-measuring instrument, which is inserted in series with the current path.",
"source": "IEC 60617 graphical symbols for diagrams",
"confidence": 7
},
"NI103": {
"revision": 2,
"explanation": "Voltage is measured in parallel with the battery, so the meter must be connected across the battery while the circuit remains operating.",
"source": "https://50ohm.de/N_spannungsmessung.html",
"confidence": 7
},
"NI104": {
"revision": 2,
"explanation": "Current through a component is measured in series, so the meter must be inserted into the path through the resistor and LED.",
"source": "https://50ohm.de/N_spannungsmessung.html",
"confidence": 7
},
"NI201": {
"revision": 2,
"explanation": "A standing-wave meter compares forward and reflected RF power, which is how antenna matching is inferred.",
"source": "https://50ohm.de/N_swr.html",
"confidence": 7
},
"NI202": {
"revision": 2,
"explanation": "To measure reflections in the antenna system, the SWR meter is inserted between the transceiver and antenna, with the transmitter on the other port.",
"source": "https://50ohm.de/N_swr.html",
"confidence": 7
},
"NI203": {
"revision": 2,
"explanation": "An ideal match has no reflected wave, so the SWR meter should read 1:1.",
"source": "https://50ohm.de/N_swr.html",
"confidence": 8
},
"NI301": {
"revision": 2,
"explanation": "A frequency counter measures the frequency of an electrical signal directly, so it is the appropriate instrument for transmitter frequency.",
"source": "https://50ohm.de/N_frequenz.html",
"confidence": 7
},
"NI401": {
"revision": 2,
"explanation": "An oscillogram is time-domain display; an amplitude spectrum is frequency-domain display showing the signal components by frequency.",
"source": "https://50ohm.de/N_wasserfall.html",
"confidence": 8
},
"NJ101": {
"revision": 2,
"explanation": "Shielding confines RF currents and fields, reducing unwanted coupling into nearby equipment or wiring.",
"source": "https://50ohm.de/NE_elektromagnetische_vertraeglichkeit.html",
"confidence": 7
},
"NJ102": {
"revision": 2,
"explanation": "Interference complaints should be handled cooperatively; arranging checks can identify whether the cause is the amateur station, the affected device or the installation.",
"source": "https://50ohm.de/NE_elektromagnetische_vertraeglichkeit.html",
"confidence": 7
},
"NJ201": {
"revision": 2,
"explanation": "Unwanted emissions waste spectrum and may interfere with other services, so a transmitter must be adjusted and filtered to avoid them.",
"source": "https://50ohm.de/NE_slide_ne_sender.html",
"confidence": 7
},
"NJ202": {
"revision": 3,
"explanation": "A dummy load provides a non-radiating matched load, letting you align the transmitter without putting test signals on the air.",
"source": "https://50ohm.de/N_dummy_load_1.html",
"confidence": 7
},
"NK101": {
"revision": 2,
"explanation": "Shielding HF stages reduces radiation and susceptibility by keeping RF energy inside the intended circuit region.",
"source": "https://50ohm.de/NE_elektromagnetische_vertraeglichkeit.html",
"confidence": 7
},
"NK102": {
"revision": 2,
"explanation": "A good RF earth gives unwanted RF currents a controlled return path and reduces coupling into equipment, cables and surroundings.",
"source": "https://50ohm.de/NE_elektromagnetische_vertraeglichkeit.html",
"confidence": 7
},
"NK201": {
"revision": 2,
"explanation": "Near antennas, electromagnetic fields can exceed exposure limits; operators need enough knowledge to keep people outside unsafe field strengths.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 7
},
"NK301": {
"revision": 2,
"explanation": "Common electrical-safety practice treats contact above 50 V AC or 120 V DC as hazardous under normal dry conditions.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 8
},
"NK302": {
"revision": 2,
"explanation": "The main electrical hazards are current through the body, arc faults, and secondary accidents such as falls caused by shock or startle.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 8
},
"NK303": {
"revision": 2,
"explanation": "Body current can heat tissue, force muscles to contract, and disturb the heart rhythm, including dangerous fibrillation.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 8
},
"NK304": {
"revision": 2,
"explanation": "Heart rhythm disturbances can be delayed after an electric shock, so medical assessment is required even when the person initially feels well.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 8
},
"NK305": {
"revision": 2,
"explanation": "A fuse protects only as designed when its current rating and time-current characteristic match the original device.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 8
},
"NK306": {
"revision": 2,
"explanation": "Rechargeable batteries can deliver high energy and contain reactive chemicals, so misuse can cause burns, chemical injury or toxic exposure.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 7
},
"NK307": {
"revision": 2,
"explanation": "A vehicle battery can supply very high short-circuit current; wrong connection can create arcs and ignite wiring or surrounding material.",
"source": "https://50ohm.de/NEA_einbau_kfz.html",
"confidence": 7
},
"NK308": {
"revision": 2,
"explanation": "Vehicle electronics and approval conditions depend on manufacturer installation limits, so those instructions govern radio installation.",
"source": "https://50ohm.de/NEA_einbau_kfz.html",
"confidence": 7
},
"NK309": {
"revision": 2,
"explanation": "Keeping coax away from vehicle wiring reduces RF coupling into control electronics and avoids parallel runs acting as coupled lines.",
"source": "https://50ohm.de/NEA_einbau_kfz.html",
"confidence": 7
},
"NK310": {
"revision": 2,
"explanation": "The centre of a metal roof gives a VHF mobile antenna a good ground plane and a more even radiation pattern around the car.",
"source": "https://50ohm.de/NEA_einbau_kfz.html",
"confidence": 7
},
"NK311": {
"revision": 2,
"explanation": "Antenna parts must be arranged so that failure cannot bring conductive parts into contact with power lines, where lethal voltages may be present.",
"source": "https://publikationen.dguv.de/regelwerk/dguv-informationen/284/sicherheit-bei-arbeiten-an-elektrischen-anlagen",
"confidence": 8
},
"VA101": {
"revision": 1,
"explanation": "The international definition is in the ITU Radio Regulations, which define radio services globally before national rules implement them.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA102": {
"revision": 1,
"explanation": "RR Article 1 defines the amateur service as self-training, intercommunication and technical investigation by authorised amateurs.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA103": {
"revision": 1,
"explanation": "The amateur-satellite service is the same amateur service carried through space stations, so its purposes stay the same.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA104": {
"revision": 1,
"explanation": "The RR definition limits amateur operators to duly authorised persons interested in radio technique solely with a personal aim and without pecuniary interest.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA201": {
"revision": 1,
"explanation": "In the RR, a station is the transmitters, receivers and accessories needed at one place to carry out a radiocommunication service.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA202": {
"revision": 1,
"explanation": "An amateur station is simply a station in the amateur service, so the service definition determines the station type.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA301": {
"revision": 1,
"explanation": "The Radio Regulations' general rules apply to all radiocommunication services unless a special rule says otherwise, so amateur radio is included.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA302": {
"revision": 1,
"explanation": "RR Article 25 restricts international amateur traffic to amateur-service purposes and personal remarks, excluding third-party business traffic.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA303": {
"revision": 1,
"explanation": "RR Article 25 forbids secrecy in amateur traffic but permits encrypted control signals for amateur-satellite control links.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA304": {
"revision": 1,
"explanation": "RR Article 25 leaves Morse-code requirements to each national administration, so Germany can decide its own examination rules.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA401": {
"revision": 1,
"explanation": "The RR divides the world into regions because frequency allocations differ by region.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA402": {
"revision": 1,
"explanation": "The RR allocation table is organised into three ITU regions.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA403": {
"revision": 1,
"explanation": "Germany is in ITU Region 1, the region covering Europe, Africa and parts of western Asia.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA404": {
"revision": 1,
"explanation": "Canada is in ITU Region 2, the region covering the Americas.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA405": {
"revision": 1,
"explanation": "Australia is in ITU Region 3, the region covering Asia-Pacific outside the Region 1/2 areas.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 9
},
"VA406": {
"revision": 1,
"explanation": "International call-sign prefixes are allocated in the Radio Regulations call-sign series table.",
"source": "https://www.itu.int/gladapp/Allocation/CallSigns",
"confidence": 9
},
"VA407": {
"revision": 1,
"explanation": "The Q code meanings are an ITU operating-code item, so the RR is the authoritative international reference.",
"source": "https://www.itu.int/pub/R-REG-RR",
"confidence": 8
},
"VB101": {
"revision": 1,
"explanation": "The CEPT Novice certificate documents a recognised novice-level exam and can simplify getting an equivalent novice individual licence abroad.",
"source": "https://docdb.cept.org/download/2768",
"confidence": 9
},
"VB102": {
"revision": 1,
"explanation": "HAREC is the harmonised CEPT examination certificate under T/R 61-02; German class A matches that level.",
"source": "https://docdb.cept.org/download/2565",
"confidence": 9
},
"VB103": {
"revision": 1,
"explanation": "A HAREC certifies a passed class-A-level exam and is used by participating administrations when issuing a local amateur licence.",
"source": "https://docdb.cept.org/download/2565",
"confidence": 9
},
"VB104": {
"revision": 1,
"explanation": "T/R 61-01 covers temporary guest operation, T/R 61-02 and ERC Report 32 harmonise exam evidence, and ECC (05)06 covers novice operation.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 8
},
"VB105": {
"revision": 1,
"explanation": "Class N is a German national class and is not covered by the CEPT visitor recommendations, so it gives no CEPT operating privilege abroad.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"VB106": {
"revision": 1,
"explanation": "CEPT Novice operation only works in countries that have implemented ECC Recommendation (05)06 and only for temporary stays without residence there.",
"source": "https://docdb.cept.org/download/2768",
"confidence": 9
},
"VB107": {
"revision": 1,
"explanation": "Class A relies on T/R 61-01; the right exists only in countries that implement that recommendation and for temporary non-resident operation.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 9
},
"VB108": {
"revision": 1,
"explanation": "Some non-CEPT countries also accept T/R 61-01 or ECC (05)06, so German A/E operators may operate there when that country has implemented the relevant recommendation.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 8
},
"VB109": {
"revision": 1,
"explanation": "CEPT guest operation is temporary; T/R 61-01 uses a stay of up to three months as the normal limit.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 9
},
"VB110": {
"revision": 1,
"explanation": "Germany's CEPT visitor prefixes are class-dependent: full CEPT visitors use DL/ and novice visitors use DO/ before the home call sign.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 9
},
"VB111": {
"revision": 1,
"explanation": "CEPT operation does not export German privileges; the visitor must follow the CEPT recommendation plus the host country's power, band and operating limits.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 9
},
"VB112": {
"revision": 1,
"explanation": "A German licence does not automatically authorise 6 m abroad; the host country's CEPT implementation and national band limits control.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 9
},
"VB113": {
"revision": 1,
"explanation": "Without CEPT implementation there is no automatic visitor privilege, so the operator needs a guest authorisation from the visited country.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 9
},
"VB114": {
"revision": 1,
"explanation": "T/R 61-01 is for individual visitor operation, not moving a German club station abroad; a club station needs a separate guest authorisation.",
"source": "https://docdb.cept.org/download/3321",
"confidence": 8
},
"VC101": {
"revision": 2,
"explanation": "The AFuG is the German statutory basis for who may participate in the amateur service and under what conditions.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__1.html",
"confidence": 10
},
"VC102": {
"revision": 1,
"explanation": "AFuG §2 defines amateur radio as amateur-to-amateur communication plus experimentation, self-training, international understanding and support of relief actions.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__2.html",
"confidence": 10
},
"VC103": {
"revision": 1,
"explanation": "AFuG §2 defines an amateur station by its transmitters, receivers, antennas and required accessories, capable of operating on amateur frequencies.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__2.html",
"confidence": 10
},
"VC104": {
"revision": 2,
"explanation": "AFuG assigns the law's administrative tasks to the Bundesnetzagentur.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__10.html",
"confidence": 9
},
"VC105": {
"revision": 1,
"explanation": "AFuG §2 defines a radio amateur as the holder of an amateur certificate or harmonised examination certificate.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__2.html",
"confidence": 10
},
"VC106": {
"revision": 1,
"explanation": "Passing the exam is not enough for transmitting; AFuG §3 requires admission to participate and a person-bound call sign.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__3.html",
"confidence": 10
},
"VC107": {
"revision": 1,
"explanation": "The admission is person-bound under AFuG §3, so it cannot be lent or transferred to another person.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__3.html",
"confidence": 10
},
"VC108": {
"revision": 1,
"explanation": "AFuG §3 sets the exam/admission requirement but no minimum age requirement.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__3.html",
"confidence": 9
},
"VC109": {
"revision": 2,
"explanation": "AFuG permits amateurs with assigned call signs to operate commercial, home-built or modified transmitters on amateur frequencies.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__5.html",
"confidence": 9
},
"VC110": {
"revision": 1,
"explanation": "AFuG rights attach to frequencies designated for the amateur service; transmitting outside those allocations is not covered.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__3.html",
"confidence": 9
},
"VC111": {
"revision": 1,
"explanation": "AFuG limits amateur traffic to communication with other amateur stations, apart from emergency exceptions.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__5.html",
"confidence": 9
},
"VC112": {
"revision": 1,
"explanation": "Third-party message relay is normally outside amateur radio, but AFuG allows support in emergency and disaster cases.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__5.html",
"confidence": 9
},
"VC113": {
"revision": 1,
"explanation": "AFuG §2 excludes commercial-economic motivation from the definition of a radio amateur.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__2.html",
"confidence": 10
},
"VC114": {
"revision": 1,
"explanation": "AFuG keeps amateur radio non-commercial, so an amateur station may not be operated for commercial-economic purposes.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__5.html",
"confidence": 9
},
"VC115": {
"revision": 1,
"explanation": "Business provision of telecommunications services is outside the amateur service and is expressly not an amateur-station purpose.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__5.html",
"confidence": 9
},
"VC116": {
"revision": 1,
"explanation": "A person-bound amateur call sign is assigned by BNetzA; using another person-bound call sign would defeat that identification rule.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__3.html",
"confidence": 9
},
"VC117": {
"revision": 1,
"explanation": "AFuG allows call signs to be changed for important reasons, especially when international requirements change.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__3.html",
"confidence": 9
},
"VC118": {
"revision": 2,
"explanation": "AFuG requires amateur stations to meet EMC protection requirements so their operation remains compatible with other equipment.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__7.html",
"confidence": 9
},
"VC119": {
"revision": 2,
"explanation": "AFuG lets amateurs deviate from EMVG immunity requirements for their own station, meaning they choose their own station's immunity level.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__7.html",
"confidence": 9
},
"VC120": {
"revision": 2,
"explanation": "For self-built amateur equipment, AFuG allows the amateur to determine the station's immunity level instead of meeting ordinary EMVG immunity requirements.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__7.html",
"confidence": 9
},
"VC121": {
"revision": 2,
"explanation": "AFuG provides that BNetzA issues a site certificate on request; this is separate from the amateur-station display procedure.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__7.html",
"confidence": 9
},
"VC122": {
"revision": 2,
"explanation": "AFuG and AFuV enforcement powers allow BNetzA to restrict operation or order an amateur station taken out of service after violations.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__11.html",
"confidence": 9
},
"VC123": {
"revision": 1,
"explanation": "Persistent violations can lead to revocation because the admission and call-sign assignment are administrative permissions tied to lawful operation.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__3.html",
"confidence": 9
},
"VC124": {
"revision": 2,
"explanation": "AFuG treats operating without admission/call sign, commercial telecom service, and unauthorised third-party message relay as fineable offences.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__9.html",
"confidence": 9
},
"VC125": {
"revision": 2,
"explanation": "An unlawful station operation can be pursued by BNetzA as an administrative offence with a monetary fine.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__9.html",
"confidence": 9
},
"VD101": {
"revision": 1,
"explanation": "AFuV §1 points to Anlage 1 for the usable frequency ranges and technical operating conditions by class.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__1.html",
"confidence": 10
},
"VD102": {
"revision": 1,
"explanation": "AFuV says receiving amateur transmissions does not require admission to the amateur service; the admission requirement is for participation by transmitting.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD103": {
"revision": 1,
"explanation": "AFuV requires open language; encryption that hides the content is not open language and is therefore prohibited.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD104": {
"revision": 1,
"explanation": "AFuV permits encryption only for control signals of satellites, remote, automatically working or otherwise remotely controlled stations.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD105": {
"revision": 1,
"explanation": "AFuV expressly forbids using international maritime and aeronautical distress, urgency and safety signals in amateur traffic.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD106": {
"revision": 1,
"explanation": "AFuV requires amateur stations to be installed and maintained according to generally recognised technical rules.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD107": {
"revision": 1,
"explanation": "AFuV lets BNetzA demand technical documents and an antenna layout sketch for a transmitting station.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD108": {
"revision": 1,
"explanation": "AFuV §17 lets BNetzA require records to investigate interference causes or clarify frequency-technical questions.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__17.html",
"confidence": 10
},
"VD109": {
"revision": 1,
"explanation": "Log-like written operating records are mandatory only when BNetzA requires them under AFuV §17.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__17.html",
"confidence": 10
},
"VD110": {
"revision": 1,
"explanation": "AFuV requires unwanted emissions to be reduced to the lowest practicable level.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD111": {
"revision": 1,
"explanation": "During adjustment and measurement, AFuV requires effective measures to prevent free radiation of test signals.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD112": {
"revision": 1,
"explanation": "A carrier is normally not a valid transmission by itself, but a short unmodulated carrier can be necessary for tuning.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 9
},
"VD113": {
"revision": 1,
"explanation": "AFuV requires name or address changes to be reported to BNetzA without undue delay.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__9.html",
"confidence": 10
},
"VD114": {
"revision": 1,
"explanation": "AFuV §15 defines the call-sign list content: name, call sign and address unless publication of the address is opposed.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__15.html",
"confidence": 10
},
"VD115": {
"revision": 1,
"explanation": "No BNetzA special permission is needed merely because the amateur station is operated in a watercraft or aircraft; other operator/vehicle permissions still matter.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"VD116": {
"revision": 1,
"explanation": "AFuV §16 allows BNetzA to grant temporary exceptions for special experimental and technical-scientific studies.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__16.html",
"confidence": 10
},
"VD117": {
"revision": 1,
"explanation": "AFuV §2 defines a club station as a station used by at least three members of a group under a jointly used call sign.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__2.html",
"confidence": 10
},
"VD118": {
"revision": 1,
"explanation": "AFuV §2 defines a repeater as a remote or automatic amateur station that re-transmits or forwards received or stored content.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__2.html",
"confidence": 10
},
"VD119": {
"revision": 1,
"explanation": "AFuV §2 defines a beacon as an automatic amateur transmitting station that repeatedly emits signals for field-strength observations or reception tests.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__2.html",
"confidence": 10
},
"VD201": {
"revision": 1,
"explanation": "AFuV §10 requires BNetzA to publish a German amateur call-sign plan that defines the call-sign formation rules.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 10
},
"VD202": {
"revision": 1,
"explanation": "AFuV §10 lists person-bound call signs and further call signs for training, remote/automatic stations and club stations.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 10
},
"VD203": {
"revision": 1,
"explanation": "The German call-sign plan uses a two-letter German prefix, one digit and usually a two- or three-letter suffix for person-bound call signs.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 9
},
"VD204": {
"revision": 1,
"explanation": "The call-sign plan permits special-event suffixes up to seven characters, including digits, provided the suffix ends with a letter.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"VD205": {
"revision": 1,
"explanation": "AFuV §11 requires the call sign at the beginning and end of each contact and at least every ten minutes during traffic.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 10
},
"VD206": {
"revision": 1,
"explanation": "BNetzA's call-sign-use rule points to the international spelling alphabet in RR Appendix 14 for identifying call signs.",
"source": "BNetzA Verfügung 13/2005; ITU RR Appendix 14",
"confidence": 8
},
"VD207": {
"revision": 1,
"explanation": "The amateur call sign is the on-air identifier; it tells listeners which amateur station is transmitting.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__11.html",
"confidence": 10
},
"VD208": {
"revision": 1,
"explanation": "AFuV §10 says there is no entitlement to a specific call sign.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__10.html",
"confidence": 10
},
"VD301": {
"revision": 1,
"explanation": "AFuV §12 defines training operation as practical preparation for the amateur-radio exam.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__12.html",
"confidence": 10
},
"VD302": {
"revision": 1,
"explanation": "AFuV §12 permits training operation only for admitted class A or E amateurs.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__12.html",
"confidence": 10
},
"VD303": {
"revision": 1,
"explanation": "AFuV §12 allows non-licensed trainees to participate only under direct instruction and supervision by an authorised class A or E amateur.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__12.html",
"confidence": 10
},
"VD304": {
"revision": 1,
"explanation": "AFuV §12 limits training operation to the operating privileges of the instructor.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__12.html",
"confidence": 10
},
"VD305": {
"revision": 1,
"explanation": "AFuV §12 requires the instructor to provide BNetzA information about the type and extent of training operation on request.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__12.html",
"confidence": 10
},
"VD306": {
"revision": 1,
"explanation": "AFuV §12 and §11 put the training suffix on the trainee's use of the instructor or club call sign.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__12.html",
"confidence": 10
},
"VD401": {
"revision": 1,
"explanation": "AFuV §14 requires the group's leader to name the responsible radio amateur for a club-station call-sign assignment.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__14.html",
"confidence": 10
},
"VD402": {
"revision": 1,
"explanation": "AFuV §14 allows a club-station call sign only to a radio amateur already admitted to participate in the amateur service.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__14.html",
"confidence": 10
},
"VD403": {
"revision": 1,
"explanation": "AFuG §3 allows further call signs, including club-station call signs, only after the amateur has an admission and the additional assignment.",
"source": "https://www.gesetze-im-internet.de/afug_1997/__3.html",
"confidence": 10
},
"VD404": {
"revision": 1,
"explanation": "Only admitted radio amateurs may transmit using a club-station call sign; the club call does not authorise unlicensed operation.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__14.html",
"confidence": 10
},
"VD405": {
"revision": 1,
"explanation": "AFuV permits admitted radio amateurs to operate at a club station even if they are not members of the group.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__14.html",
"confidence": 10
},
"VD406": {
"revision": 1,
"explanation": "When operator class and club-station class differ, the lower privilege set controls frequency and power limits.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__14.html",
"confidence": 10
},
"VD407": {
"revision": 2,
"explanation": "AFuV Anlage 1 lists 7.000-7.200 MHz only in the class A column. A class A club-station call sign does not expand the operator's own licence privileges, so only class A operators may use 40 m there.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD408": {
"revision": 1,
"explanation": "AFuV does not require reporting short-term location changes of a club station, unlike permanent relevant assignment data changes.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__14.html",
"confidence": 9
},
"VD501": {
"revision": 1,
"explanation": "AFuV §13 requires a separate call-sign assignment for remote-controlled or automatically working stations such as repeaters and beacons.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13.html",
"confidence": 10
},
"VD502": {
"revision": 1,
"explanation": "A repeater may be operated only under its own assigned call sign and the site and operating conditions stated in that assignment.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13.html",
"confidence": 10
},
"VD503": {
"revision": 1,
"explanation": "AFuV Anlage 1 limits repeater stations above 30 MHz to 50 W ERP.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD504": {
"revision": 1,
"explanation": "The responsible operator may exclude a user when that is necessary to keep the repeater operating without interference.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13.html",
"confidence": 9
},
"VD601": {
"revision": 1,
"explanation": "AFuV §2 defines remote operation as unoccupied, remotely controlled operation of a fixed amateur station under continuous indirect control.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__2.html",
"confidence": 10
},
"VD602": {
"revision": 1,
"explanation": "AFuV §13a links remote operation to a BNetzA notification by the remote-station operator.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13a.html",
"confidence": 10
},
"VD603": {
"revision": 1,
"explanation": "AFuV §13a restricts remote operation to holders of class A privileges.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13a.html",
"confidence": 10
},
"VD604": {
"revision": 1,
"explanation": "AFuV §13a allows class A club stations to be used for remote operation.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13a.html",
"confidence": 10
},
"VD605": {
"revision": 1,
"explanation": "Remote operation must remain under the operator's continuous indirect control, so the operator must be able to maintain operational safety.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__2.html",
"confidence": 10
},
"VD606": {
"revision": 1,
"explanation": "The remote-station operator must prevent unauthorised or abusive access, so only specifically authorised amateurs may use it.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13a.html",
"confidence": 10
},
"VD607": {
"revision": 1,
"explanation": "AFuV §13a permits transmission through a remote station only by authorised amateurs with class A admission.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13a.html",
"confidence": 10
},
"VD608": {
"revision": 1,
"explanation": "BNetzA needs the operator's contact details so it can reach the responsible person quickly in case of radio interference.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13a.html",
"confidence": 10
},
"VD609": {
"revision": 1,
"explanation": "For a remotely operated club station, AFuV §13a limits access to members of the operating group.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/__13a.html",
"confidence": 10
},
"VD701": {
"revision": 1,
"explanation": "International RR allocations are not self-executing in Germany; AFuV Anlage 1 and BNetzA notices implement the usable national amateur ranges.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD702": {
"revision": 1,
"explanation": "AFuV Anlage 1 is the national table for German amateur frequency ranges and detailed usage conditions.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD703": {
"revision": 1,
"explanation": "CB radio is outside the amateur frequency allocations, so an amateur station is not authorised to transmit there.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD704": {
"revision": 1,
"explanation": "A primary service can claim protection from secondary services, so secondary stations must not interfere with it.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD705": {
"revision": 1,
"explanation": "A secondary service may neither cause harmful interference to primary services nor claim protection from them.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD706": {
"revision": 1,
"explanation": "AFuV Anlage 1 lists 7000-7200 kHz with primary status for the amateur service.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD707": {
"revision": 1,
"explanation": "A coastal station on its fixed assigned frequency cannot simply move; even in a shared primary band the amateur station must stop using that frequency unless a real emergency exists.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 9
},
"VD708": {
"revision": 1,
"explanation": "The 433.05-434.79 MHz ISM designation means non-communication industrial, scientific, medical, domestic or similar applications also use that range.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD709": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 1810 to 2000 kHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD710": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 3.5 to 3.8 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD711": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 7 to 7.2 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD712": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 10.1 to 10.15 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD713": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 14 to 14.35 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD714": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 18.068 to 18.168 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD715": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 21 to 21.45 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD716": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 24.89 to 24.99 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD717": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 28 to 29.7 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD718": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 50.0 to 52.0 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD719": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 144 to 146 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD720": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 430 to 440 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD721": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 1240 to 1300 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD722": {
"revision": 1,
"explanation": "This is a direct AFuV Anlage 1 table value: the German amateur allocation is 2320 to 2450 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD723": {
"revision": 1,
"explanation": "AFuV Anlage 1 gives class N only the 10 m, 2 m and 70 cm ranges: 28-29.7 MHz, 144-146 MHz and 430-440 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD724": {
"revision": 1,
"explanation": "For class N on 2 m and 70 cm, AFuV Anlage 1 uses an EIRP cap of 10 W rather than a transmitter-output cap.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD725": {
"revision": 1,
"explanation": "EIRP is transmitter power times antenna gain relative to isotropic: $5 W \\cdot 2.5 = 12.5 W$, which exceeds the 10 W class N limit.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD726": {
"revision": 1,
"explanation": "EIRP is transmitter power times antenna gain relative to isotropic: $5 W \\cdot 1.8 = 9 W$, which stays below the 10 W class N limit.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD727": {
"revision": 1,
"explanation": "AFuV Anlage 1 permits class E operation from 1810 to 1850 kHz with a maximum of 100 W PEP.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD728": {
"revision": 1,
"explanation": "AFuV Anlage 1 lists 750 W PEP for class A in the 3.5-3.8 MHz band.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD729": {
"revision": 1,
"explanation": "AFuV Anlage 1 gives 3.5-3.8 MHz limits of 750 W PEP for class A and 100 W PEP for class E.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD730": {
"revision": 1,
"explanation": "AFuV Anlage 1 limits class A in 10.1-10.15 MHz to 150 W PEP.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD731": {
"revision": 1,
"explanation": "AFuV Anlage 1 lists 750 W PEP for class A on both 14.000-14.350 MHz and 18.068-18.168 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD732": {
"revision": 1,
"explanation": "AFuV Anlage 1 lists 750 W PEP for class A on both 21.000-21.450 MHz and 24.890-24.990 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD733": {
"revision": 1,
"explanation": "AFuV Anlage 1 gives 21 MHz and 28 MHz limits of 750 W PEP for class A and 100 W PEP for class E.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD734": {
"revision": 1,
"explanation": "AFuV Anlage 1 gives 144-146 MHz and 430-440 MHz limits of 750 W PEP for class A and 75 W PEP for class E.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD735": {
"revision": 1,
"explanation": "AFuV Anlage 1 allows class A up to 750 W PEP at 1240-1300 MHz but adds a special 5 W EIRP cap in 1247-1263 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD736": {
"revision": 1,
"explanation": "For class A between 1300 MHz and 250 GHz, AFuV Anlage 1 lists a maximum transmitter output of 75 W PEP.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD737": {
"revision": 1,
"explanation": "For class E between 1300 MHz and 250 GHz, AFuV Anlage 1 lists a maximum transmitter output of 5 W PEP.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD738": {
"revision": 1,
"explanation": "AFuV Anlage 1 sets the narrow 800 Hz occupied-bandwidth limit for 135.7-137.8 kHz, 472-479 kHz and 10.100-10.150 MHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD739": {
"revision": 1,
"explanation": "AFuV Anlage 1 gives 3.5-3.8 MHz a maximum occupied bandwidth of 2.7 kHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD740": {
"revision": 1,
"explanation": "AFuV Anlage 1 gives 28.000-29.000 MHz a maximum occupied bandwidth of 7 kHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD741": {
"revision": 1,
"explanation": "AFuV Anlage 1 gives 144-146 MHz a maximum occupied bandwidth of 40 kHz.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD742": {
"revision": 1,
"explanation": "AFuV Anlage 1 gives 430-440 MHz a 2 MHz occupied-bandwidth limit, with 7 MHz allowed for AM television transmissions.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VD743": {
"revision": 1,
"explanation": "AFuV Anlage 1 caps class N in the 10 m band at 10 W ERP.",
"source": "https://www.gesetze-im-internet.de/afuv_2005/anlage_1.html",
"confidence": 10
},
"VE101": {
"revision": 1,
"explanation": "The TKG is a general telecommunications law; amateur radio has its own law, but frequency-use and enforcement rules from the TKG can still apply.",
"source": "https://www.gesetze-im-internet.de/tkg_2021/BJNR185810021.html",
"confidence": 9
},
"VE102": {
"revision": 1,
"explanation": "TKG §91 states the general rule that every frequency use needs a prior frequency assignment unless the law provides otherwise.",
"source": "https://www.gesetze-im-internet.de/tkg_2021/BJNR185810021.html",
"confidence": 10
},
"VE103": {
"revision": 1,
"explanation": "Using frequencies without the required frequency assignment is a TKG administrative offence.",
"source": "https://www.gesetze-im-internet.de/tkg_2021/BJNR185810021.html",
"confidence": 10
},
"VE201": {
"revision": 1,
"explanation": "Unauthorised listening to the non-publicly spoken word is a criminal offence under StGB §201, independent of holding an amateur licence.",
"source": "https://www.gesetze-im-internet.de/stgb/__201.html",
"confidence": 10
},
"VE202": {
"revision": 1,
"explanation": "TDDDG protects communications not intended for the recipient; receiving, using or passing on such messages violates that confidentiality duty.",
"source": "https://www.gesetze-im-internet.de/ttdsg/__5.html",
"confidence": 10
},
"VE203": {
"revision": 1,
"explanation": "TDDDG §5 bars disclosing both the content and the fact of receiving non-public/non-general messages, except where emergency and disaster rules justify it.",
"source": "https://www.gesetze-im-internet.de/ttdsg/__5.html",
"confidence": 10
},
"VE204": {
"revision": 1,
"explanation": "TDDDG prohibits disguised transmitting devices suited to unnoticed eavesdropping on non-public speech, including possession and manufacture.",
"source": "https://www.gesetze-im-internet.de/ttdsg/__5.html",
"confidence": 10
},
"VE301": {
"revision": 1,
"explanation": "Before escalating an EMC dispute, reducing power is a practical interim measure that may remove the interference and preserve neighbourly peace.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 8
},
"VE302": {
"revision": 1,
"explanation": "If local remedies fail, BNetzA is the competent authority to investigate radio-interference causes.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 9
},
"VE303": {
"revision": 1,
"explanation": "When both installations are compliant but incompatibility remains, EMVG gives BNetzA authority to arrange remedial measures with the parties.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 9
},
"VE304": {
"revision": 1,
"explanation": "EMVG lets BNetzA arrange remedial measures in cooperation with affected parties when compliant equipment still causes a local EMC problem.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 9
},
"VE305": {
"revision": 1,
"explanation": "If the amateur field strength at the affected receiver is below the relevant immunity reference level, the amateur station is not the non-compliant part and may continue operation.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 8
},
"VE306": {
"revision": 1,
"explanation": "If the field strength at the cable system stays below the recommended immunity level, the amateur transmission is within the assumed compatibility boundary.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 8
},
"VE307": {
"revision": 1,
"explanation": "If all bands are disturbed, the likely source is local household electronics, so checking local supplies, lamps, computers and displays is the fastest first isolation step.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 7
},
"VE308": {
"revision": 1,
"explanation": "A receiver has no general right to be free of all interference; compliant devices under EMVG or FuAG may still produce disturbance the amateur must tolerate.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 9
},
"VE309": {
"revision": 1,
"explanation": "A time/type log and suspected source give BNetzA evidence for pattern matching and field investigation of recurring interference.",
"source": "https://www.gesetze-im-internet.de/emvg_2016/BJNR287910016.html",
"confidence": 8
},
"VE401": {
"revision": 1,
"explanation": "The FuAG implements the market rules for radio equipment, including making radio equipment available, free movement and putting it into service.",
"source": "https://www.gesetze-im-internet.de/fuag/FuAG.pdf",
"confidence": 10
},
"VE402": {
"revision": 1,
"explanation": "Radio equipment made available on the market, including amateur equipment sold commercially, falls under the FuAG.",
"source": "https://www.gesetze-im-internet.de/fuag/FuAG.pdf",
"confidence": 10
},
"VE403": {
"revision": 1,
"explanation": "Serially manufactured amateur radio equipment is market equipment, so it must meet FuAG essential requirements and carry CE marking.",
"source": "https://www.gesetze-im-internet.de/fuag/FuAG.pdf",
"confidence": 10
},
"VE404": {
"revision": 1,
"explanation": "Commercial receivers capable of receiving amateur frequencies are market radio equipment, so FuAG requirements apply.",
"source": "https://www.gesetze-im-internet.de/fuag/FuAG.pdf",
"confidence": 10
},
"VE405": {
"revision": 1,
"explanation": "FuAG excludes amateur radio equipment assembled by radio amateurs for experimental and scientific purposes, so those home-built stations do not need FuAG conformity proof.",
"source": "https://www.gesetze-im-internet.de/fuag/FuAG.pdf",
"confidence": 10
},
"VE501": {
"revision": 1,
"explanation": "EMVU is the environmental side of electromagnetic compatibility: protecting people and the environment from electromagnetic fields.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 9
},
"VE502": {
"revision": 1,
"explanation": "The fixed amateur-station operator is responsible for demonstrating and maintaining electromagnetic environmental compatibility at the site.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE503": {
"revision": 1,
"explanation": "The BEMFV is the regulation that sets the proof procedure for limiting electromagnetic fields from fixed amateur stations.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE504": {
"revision": 1,
"explanation": "The BEMFV amateur display procedure lets the amateur independently calculate, document and declare that person-safety limits are met.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE505": {
"revision": 1,
"explanation": "Person-protection field limits come from the 26th BImSchV and are applied through the BEMFV proof procedure.",
"source": "https://www.gesetze-im-internet.de/bimschv_26/BJNR196600996.html",
"confidence": 10
},
"VE506": {
"revision": 1,
"explanation": "For fixed amateur stations at 10 W EIRP or more, BEMFV requires the safety distance to be determined by calculation or measurement and documented.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE507": {
"revision": 1,
"explanation": "The BEMFV documentation threshold for fixed amateur stations is 10 W EIRP.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE508": {
"revision": 1,
"explanation": "Every operator of a fixed amateur station at or above 10 W EIRP must use the BEMFV notification procedure.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE509": {
"revision": 1,
"explanation": "The BEMFV notification must be submitted to the responsible BNetzA field office before starting operation.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE510": {
"revision": 1,
"explanation": "If the actual station no longer matches the existing notification, the BEMFV procedure must be repeated.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE511": {
"revision": 1,
"explanation": "The notification is the amateur's binding declaration that the statutory person-protection limits are met under their own responsibility.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE512": {
"revision": 1,
"explanation": "BEMFV requires a clear drawing of the site-related safety distance and the area controlled by the operator with the notification.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE513": {
"revision": 1,
"explanation": "From commissioning onward, the operator must keep the supporting compliance documentation ready for BNetzA, including antenna data and site drawings as needed.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE514": {
"revision": 1,
"explanation": "After notification, the operator must keep the documentation current and re-notify after material changes that invalidate the original assumptions.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE515": {
"revision": 1,
"explanation": "BNetzA accepts several proof methods for amateur stations, including WattWächter, simplified assessment, measurements, and near- or far-field calculations.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"VE516": {
"revision": 1,
"explanation": "The safety distance must cover all emissions the operator intends to make simultaneously, because simultaneous fields add at the exposure location.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE517": {
"revision": 1,
"explanation": "Overlapping safety distances require joint assessment when the antennas can transmit at the same time, because exposure is combined.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE518": {
"revision": 1,
"explanation": "If other certificate-requiring fixed radio systems are already at the site and total site EIRP reaches 10 W, BEMFV requires a site certificate.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE519": {
"revision": 1,
"explanation": "For a fixed amateur station, BEMFV requires a site certificate only when the intended site already has fixed radio systems subject to the site-certificate procedure.",
"source": "https://www.gesetze-im-internet.de/bemfv/__8.html",
"confidence": 10
},
"VE601": {
"revision": 1,
"explanation": "Electrical safety for home-built equipment follows generally recognised engineering practice, which is why VDE rules are the relevant benchmark.",
"source": "VDE 0855-300 and DIN EN 62305/VDE 0185-305",
"confidence": 7
},
"VE602": {
"revision": 1,
"explanation": "Outdoor antenna structures are building works, so the applicable construction law is the law of the German federal state where they are erected.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"VE603": {
"revision": 1,
"explanation": "Recognised lightning-protection rules for antenna installations are published as VDE standards.",
"source": "VDE 0855-300 and DIN EN 62305/VDE 0185-305",
"confidence": 7
},
"VE604": {
"revision": 1,
"explanation": "VDE 0855-300 applies to equipotential bonding and earthing of amateur transmitting installations; the VDE 0185-305 lightning-protection series applies when the building has a lightning-protection system.",
"source": "VDE 0855-300 and DIN EN 62305/VDE 0185-305",
"confidence": 7
},
"VE701": {
"revision": 1,
"explanation": "Licensed amateurs owe annual frequency-protection contributions under TKG and EMVG cost-recovery rules.",
"source": "Frequenzschutzbeitragsverordnung (FSBeitrV)",
"confidence": 8
},
"VE702": {
"revision": 1,
"explanation": "The annual frequency-protection contribution is tied to having an amateur admission, regardless of how much the station is used.",
"source": "Frequenzschutzbeitragsverordnung (FSBeitrV)",
"confidence": 8
},
"VE703": {
"revision": 1,
"explanation": "The BNetzA fee regulation charges for individually attributable acts such as admission to the amateur service and assignment of a person-bound call sign.",
"source": "Besondere Gebührenverordnung BNetzA (BNetzABGebV)",
"confidence": 8
},
"VE704": {
"revision": 1,
"explanation": "Unpaid public fees and contributions can be enforced administratively under the Verwaltungs-Vollstreckungsgesetz.",
"source": "Verwaltungs-Vollstreckungsgesetz (VwVG)",
"confidence": 8
},
"VE705": {
"revision": 1,
"explanation": "Aircraft operation requires the consent of the pilot in command because that person is responsible for the aircraft and onboard radio use.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"VE706": {
"revision": 1,
"explanation": "On a ship in international waters, amateur operation is possible only with the master's consent because the master controls shipboard operations.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
},
"VE707": {
"revision": 1,
"explanation": "Damage caused by an antenna installation is a civil-liability issue for the owner or operator who controls that installation.",
"source": "https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/Amateurfunk/Fragenkatalog/BetriebVorschriftFragKlAuEId7830pdf.pdf?__blob=publicationFile",
"confidence": 8
}
}
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