I went to bed worrying about this one. John KN6FVK had been having a lot of problems. He had repeatedly reported hearing nothing (crickets!) when he fired up the receiver. Members of the Discord group had provided a lot of coaching, but still, CRICKETS! John had a good sense of humor. When I pointed out that oscillations in the AF amp are caused by a feedback path that meets "the Barkhausen criteria" John said he went to Lowes and bought a spray can of Barkhausen-Be-Gone. It seems to have worked. Actually I think John put some additional capacitance on the DC rail of the AF amp. In any case, he was going to wait for the evening for test out the fixed receiver. The time difference with California meant that I went to bed with fingers crossed. Happily the BBG spray and (more likely) the extra capacitance worked. John sent us some really nice videos of his receiver in action. I really like the inscriptions on his pine board. This should become "a thing."
John writes:
I'm very ok now.... --- sigh / smile --- THANK YOU ALL for your help and patience. As painful as this was, it was a lot of fun and I learned a lot. After I build an actual work bench, I might try this again (looks are important). But I'm definitely going to start playing with it and learning from it. On to Mods and Upgrades! Need to learn-up on this "Barkhausen" silliness too. -73
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). I am surprised at how well my set up works. Sometimes.
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