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I'm sorry Thomas, In my New Years festive mood I misread your first post and thought you were talking about an earlier design- not the new Bitx40 smd version. Farhan is, of course, the expert and he knows the ins and out completely. Heat seems to be the usual suspect and perhaps NPO caps might be some benefit but ultimately a digital VFO may be the answer you're looking for. Unless! you want to take a detour and take a huff and puff circuit for a spin. :) John KC9OJV From: "Thomas Noel tnoel@... [BITX20]" To: BITX20@... Sent: Saturday, December 31, 2016 10:14 PM Subject: Re: [BITX20] Sad reality of stock vfo
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John, As I said - I knew from others¡¯ experience that the stock design has some significant limitations. I just had no previous personal experience with such builds. I have read of quite a few design mods that offer improvement. The design is simple and easy to mod as Farhan intended. I built the stock design as a starting place for learning.? I was surprised to see the drift so severe that it is hard to hold frequency during an ¡°over¡±. I have made more than a dozen QSOs in less than two hours of operation. The operator on the other end even commented that I was drifting off frequency. I would like to continue to experiment with the all-analog radio before moving to the DDS VFO. Where exactly would you start? Replace the resistors as suggested by Farhan? They were included with my purchase. Which capacitors would you replace to stabilize the VFO, and change just the type, or change any of the values? My tuning range is just where I would want it now. If anyone can give me a step-by-step attack plan in order of best anticipated return on effort, I would appreciate it a lot. Thomas W Noel KF7RSF
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