[hpsdr] Pennywhistle bias control failure

[Greg - ZL3IX]

Hi Chris,

Since you have borrowed an FT817 to monitor your own signal, have you 
tried running your Tx into a dummy load to see if you have the same 
problem?   If it goes away, then RF feedback is clearly your problem.

73, Greg, ZL3IX (G3ZZI)

On 2010-05-16 20:00, Chris Smith wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> John
>
> I'm not absolutely sure about the RF feedback but the symptoms are that on 20M and above, although I'm apparently (from reports) generating a strong signal, the audio is very distorted. I borrowed  an FT817 from G4EFO and monitored my signal and can confirm that this is the case. This only started happening after I went from an electret mic to a moving coil mic - both on booms from a headset - plus the inclusion of an extra connector at the metal plate.
>
> In the past distorted audio has usually been because of a) overdriven modulator or b) RF feedback.  The distortion seems to occur at even moderate mic gain settings so I assumed b). Remember this doesn't occur on 80M or 40M.
>
> Cheers&  73
>
> Chris G4NUX
>
>
> On 16 May 2010, at 06:39, John Petrich wrote:
>    
>

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