From e5af931c0af2aac53f94bbddec86ceec85cef738 Mon Sep 17 00:00:00 2001 From: Renat Nurgaliyev Date: Sat, 23 May 2026 12:13:27 +0200 Subject: [PATCH] Touch up some explanations --- explanations.json | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/explanations.json b/explanations.json index 7b1abd9..b6b8d70 100644 --- a/explanations.json +++ b/explanations.json @@ -258,8 +258,8 @@ "confidence": 8 }, "AB402": { - "revision": 2, - "explanation": "The first overtone is the second harmonic, so the third overtone is one step higher again: the fourth harmonic.", + "revision": 3, + "explanation": "Overtones count only the harmonics above the fundamental: 1st overtone = 2nd harmonic, 2nd overtone = 3rd harmonic, 3rd overtone = 4th harmonic.", "source": "https://50ohm.de/A_slide_a_sender.html", "confidence": 8 }, @@ -690,8 +690,8 @@ "confidence": 8 }, "AC524": { - "revision": 1, - "explanation": "A flyback diode is placed antiparallel across the coil, reverse-biased during normal operation and forward-biased for the coil's turn-off current.", + "revision": 2, + "explanation": "When the switch opens, the inductor tries to maintain its current and reverses the voltage across itself. The flyback diode is wired antiparallel so it forward-conducts at that moment, providing a safe current path and clamping the back-EMF that would otherwise destroy the switching transistor.", "source": "https://50ohm.de/A_transistor_2.html", "confidence": 7 }, @@ -1056,8 +1056,8 @@ "confidence": 7 }, "AD313": { - "revision": 1, - "explanation": "Regularly spaced unwanted signals around 120 kHz are typical of switch-mode supply switching frequency and its related emissions.", + "revision": 2, + "explanation": "Spurs spaced 120 kHz apart across the spectrum point to a switch-mode supply: its switching frequency and harmonics radiate at multiples of that fundamental rate.", "source": "https://50ohm.de/A_schaltnetzteil_2.html", "confidence": 8 }, @@ -3678,8 +3678,8 @@ "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.", + "revision": 3, + "explanation": "Eddy currents induced in the conductive copper or aluminium core oppose the changing RF flux, partially cancelling the field inside the core and shrinking the effective magnetic cross-section, so inductance drops. The catalog phrases this as the field 'not penetrating' the core — a simplification of what physically happens, but the wording to memorize.", "source": "https://50ohm.de/NEA_spule_1.html", "confidence": 7 }, @@ -4332,8 +4332,8 @@ "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.", + "revision": 3, + "explanation": "A silicon BJT conducts when its forward-biased base-emitter junction reaches its threshold; for silicon that is about 0.6 to 0.7 V.", "source": "https://50ohm.de/NEA_slide_nea_bauelemente.html", "confidence": 8 }, @@ -5274,8 +5274,8 @@ "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.", + "revision": 2, + "explanation": "A quarter-wave vertical against a counterpoise has a feed impedance near 35 Ohm with horizontal radials; sloping the radials downward raises it toward 50 Ohm, so the practical range is about 30 to 50 Ohm.", "source": "https://50ohm.de/E_fusspunktimpedanz_1.html", "confidence": 8 }, @@ -6018,8 +6018,8 @@ "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.", + "revision": 2, + "explanation": "An indoor antenna sits inside the noisy local RF environment and gets little wanted signal; an outdoor antenna can be placed away from the interferer and offers more gain and directivity, improving the wanted-to-interferer ratio.", "source": "https://50ohm.de/E_slide_e_sender.html?print-pdf=&showNotes=true", "confidence": 8 }, @@ -6240,8 +6240,8 @@ "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.", + "revision": 2, + "explanation": "An existing building earthing system per VDE 0855-300 may be used for antenna earthing; no separate electrode or special approval is required.", "source": "https://50ohm.de/NE_blitzerdung.html", "confidence": 8 },