04-20-2020, 07:12 PM
Lots more head scratching, not much more progress.
One thing I notice, looking at the design of the coil. As wired, The primary for broadcast is 34 ohms, the primary for Band B (up to 5 MHz) 0.5 ohms and the primary for Band C (up to 18 MHz) is 2 ohms. Measuring their inductances, band B has less inductance than band C. This looks the wrong way around for the two SW coils. More-over, the higher frequency coil is close wound from fine wire, where typically it should be spaced a little, and larger gauge wire for the higher frequency.
I am wondering if the antenna coils for SW are mis wired? It seems possible to change the wiring over and retest - nothing permanent need be done.
One thing I notice, looking at the design of the coil. As wired, The primary for broadcast is 34 ohms, the primary for Band B (up to 5 MHz) 0.5 ohms and the primary for Band C (up to 18 MHz) is 2 ohms. Measuring their inductances, band B has less inductance than band C. This looks the wrong way around for the two SW coils. More-over, the higher frequency coil is close wound from fine wire, where typically it should be spaced a little, and larger gauge wire for the higher frequency.
I am wondering if the antenna coils for SW are mis wired? It seems possible to change the wiring over and retest - nothing permanent need be done.
I don't hold with furniture that talks.
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