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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.

73 – Jerry – W0PWE

Well, it doesn't sound bad Jerry, but I do hear the pull of the CW note.

I presume you've tried different a oscillator tube?

Have you looked at the output at the vfo on a scope?

GL es 73 Steve w8tow?

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Hi Steve. It is good to hear from you. It has been a while since we last talked on the DX60 Net.?

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I have cycled several 6BA6 tubes through the oscillator and tonight I repeated that exercise. I have one that sounds just a little better than the others so maybe a new tube would be worth a try. I thought one of the ones I had was NOS but it is pretty hard to tell.?

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The 5MHz VFO signal looks good on the scope. It is a decent sine wave and looks the same with key down as it does with key up. At the key down transition I'm seeing some high frequency distortion but it only lasts for about two cycles of the 5MHz signal. It could easily be my scope picking up transients at that point.?

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I now have solid state regulators on the VFO screen and plate. Hopefully some day I can take those out. This thing has been driving me nuts. It almost sounds OK but I'm just not quite satisfied with it.?

Thanks for your help. 73. Jerry - W0PWE