Re: Building the 'Minimod' AM modulator-questions!
That's looking promising Mike. Did you ever swap the two coils over - o/p to VFO to test?
From what you describe it seems it was a mechanical fault, rather than the wrong type of core, although who knows, a high resistance internal soldered joint to one of the pins or some loose turns might have been the cause.
I admire your perseverance. If it had been me I may well have just chucked it on the "this design is a load of c***" pile!
I have heard of the gate diode in FET oscillators causing drift problems (and in practice they don't seem to do much anyway in a very low power oscillator), but seemingly not this time.
Anyway, let us know the final outcome.
Ian
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