I too had some trouble getting external VFO sigs through to the mixer.?? I suspected a bad Q9, but turned out that the transistor was good. (Check the voltages without the Raduino connected.)?? You might have to remove C91 and/or C92.?? On my 40 meter rig, with an analog VFO running at around 5 MHz, I had to remove C91 to get sufficient signal through to the mixer.? On my 60 meter BITX, with an Si5351 running at around 17 MHz, I removed BOTH C91 and C92.?? 73? Bill? N2CQR
On Tuesday, March 21, 2017 12:29 AM, Raj vu2zap <vu2zap@...> wrote:
IF Q9 is bad some RF from Raduino will get through to the next transistor
and RX will work.
I had a 1K open in the 3rd VFO stage and 3904 blown!
Finally got back to troubleshooting my BITX40 transmitter failure.
Using Randy K7AGE voltage chart, the only stage that had bad DC voltages
was Q9, with just a few milivolts on the base, emitter and collector.
What I don't understand is that Q9 is used in both transmit and receive
and yet my BITX40 receiver seems to be working.
Any thoughts, and also any suggestions on how to "test"
Q9?
