19-04-2020, 05:03 PM
Someone here with TV experience may have good guidance. As noted it is a Harley oscillator with tuning to give variation in tone. At a push the tone could also be varied, if a fixed tapped coil is used, by a variation in the capacitance across the tuned circuit but you would need to juggle a few figures to get an idea of range. Varying the capacitance with those values would probably have to be switched rather than variable. Personally I have tended to use Colpitts oscillators at such low frequencies as they don't require a tapped coil but obviously it would mean a different circuit. Another thought I have is whether two 50mH coils would work Ok as the tuned circuit is still effectively 100mH (two 50mH in series) and the tap can be taken between the two. My theory gets a bit iffy as regards Q and suchlike at this point though. All in all a nice original design would maybe look best (thinking aloud here so worry not about the rambling and ignore if a distraction).
I will re-iterate though that there are a few people here who will have ideas on the coil.
Tracy
I will re-iterate though that there are a few people here who will have ideas on the coil.
Tracy
