[Collins] 75A3 Problem

[Ben Wallace]

I have a very nice 75A3 that slightly distorts on SSB.  Here are the 
details -- I hope someone has seen this before to help shorten my 
troubleshooting time.

Symptoms:

a)  Distorts in SSB mode -- both 6 khz and 3.1 khz filter positions.  It 
has a slight choppy sound to it -- though you can still understand with 
very little trouble

b)  Turning down the RF gain completely eliminates the distortion -- 
BTW....the receiver has the product detector mod (it is a Howard Mills 
receiver -- 2nd owner since redone)

c)  Turning up the audio gain to position 7 and beyond causing the receiver 
to break into oscillation (motorboat sound -- very low pitch).  This occurs 
when using the speaker and headphones (speaker muted).

Anyone seen this before?  Before I fire up the test equipment bench, sure 
would like some comments.

73 -- Ben
WB8HUR San Diego