Re: Trouble With Alternate Audio Inputs (BITX40 Module)

Michael Davis <maddmd818@...>

Jerry, you may have seen my recent post. My Bitx40 is not transmitting. Per your write-up, I have checked all transistor voltages and they closely match Randy's listing. At a firum members suggestion, I checked voltage at the electret capsule in transmit, it's 3.99vdc. I assume this is correct. Not sure where to now go in the audio input chain. I dont have a signal gen or signal tracer. Maybe I can try a transistor radio audio output via a small capacitor into the audio chain but it sure is hard to follow, starting at Q12. Any thoughts?

On Sun, Mar 26, 2017 at 07:33 pm, Jerry Gaffke wrote:

Not sure exactly what is going wrong there, but all those large caps and coils might be causing trouble somehow.  I'd remove the 470uH coils and replace the 100uf with 1uF (no point in having a series cap that's much bigger than the existing C121), see if that works.  If it doesn't, then try getting by without the transformer.


On Sun, Mar 26, 2017 at 07:02 pm, <bruce@...> wrote:

For some reason when I key the rig there is an oscillation that puts the rig into full RF output.


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