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

[Jim Brown]

On 10/17/2013 7:43 PM, Jim Barber wrote:
> 160M AM, (100W carrier, 400W PEP) into two different antennas and all 
> said the hum was very loud. Move to 75M or higher and it 

Are you running AM on the other bands too? If it's not there (or not 
strong) on SSB, I'd suspect filter cap(s) in the HV string.  I don't 
work AM, but on CW, I've had exactly that symptom, with exactly that cause.

73, Jim K9YC