I apologize for coming back here and begging for help with yet another thorny HT-46 problem, but I am at wits end. The VFO drift problem is solved and now I am addressing the chirpy CW note.
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I listened to the VFO with a general coverage receiver and hear little or no frequency change at key down, but I don’t know where else the chirp could be coming from. ?I’m testing on 80M so the heterodyne oscillator is out of play. I have listened to the carrier oscillator and it does not vary. Perhaps most telling is that when I transmit using the SX-146 receiver VFO in slave mode, there is no chirp.
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I thought VFO screen voltage might be the problem but I changed the OA2 with a NOS tube and that didn’t help. I even built up a solid state screen voltage regulator and installed it in place of the screen resistor. Screen voltage is now rock solid but there was little or no improvement in the chirp.
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To demonstrate the problem I attached an audio clip from a WEB SDR where I transmitted using the receiver VFO and then using the transmitter VFO. I don’t know if 开云体育 allows .wav attachments but it seemed to upload OK. Any suggestions are welcome.
