[Elecraft] K3 AGC Mush

[Wayne Burdick]

David Gilbert wrote:

> Here's a point that I think a lot of people are missing, though ...  
> the
> signals need to be pretty weak.  As someone else recently mentioned,  
> the
> problem doesn't occur on strong signals.  If you have a high ambient
> noise level you may never even have the opportunity to notice the  
> problem.

In some cases, I understand, turning AGC off helps with this "small- 
signal" phenomenon. When Lyle gets back from vacation, we could  
experimentally increase the range of threshold and slope settings with  
AGC on to see if that helps, too. Another thing we might want to try  
is a variation on RF GAIN that controls only the DSP gain--not the  
hardware gain. This may have less effect on the noise floor than the  
current RF gain implementation.

Also see my earlier email regarding the possibility that stronger out- 
of-DSP-passband signals could be causing problems for weak signals due  
to phantom hardware AGC modulation.

Wayne
N6KR