[Amps] Alpha 76A - 120hz hum on 160m only

[Jim Brown]

On 10/17/2013 6:22 AM, TexasRF at aol.com wrote:
> Jim, it is possible that the hum is present only in your local receiver and
>   not actually being transmitted.
>   
> As a test, you might have a local listen to the signal and give you a
> report.

That's good advice.  The RF may be getting into your RX via a Pin One 
Problem on audio or control leads. Hum is a common symptom of a gain 
stage going non-linear due to RFI.  There's a discussion of "The Pin One 
Problem" in http://k9yc.com\RFI-Ham.pdf   and in several other tutorials 
on http://k9yc.com/publish.htm  in the section on audio.

73, Jim K9YC