Yes, replacing V4 did the trick! Now it sounds just like the lower bands !! Thanks a lot... boy this is a very nice BA.. if I could just modify it to get AVC working on SSB that would be great. Playing with the rf gain all the time gets old after a while.
Glad your HQ-160 is now working as it should.
The combination of using a product detector but not setting it up for AGC on CW/SSB was an odd design choice. The National NC-270 has the same setup and although a comparison between the two is apples and oranges I much prefer the HQ-160 over my NC-270.
The Hammarlund HC-10 SSB adapter works very well with the HQ-160 and using a HC-10 with the HQ-160 provides perhaps the most versatile setup of the HQ series. For AM you still have the broader bandwidth available when conditions are good and the HC-10 provides narrower bandwidths and selectable sideband on AM when conditions are rough. For SSB you get AGC with selectable release times. The HC-10 provides you with the equivalent of the final mixer, 60 Khz. IF, detector, and audio system of the HQ-170 and also has a slot filter and noise limiter. It is self contained except for speaker and all it needs is the 455 Khz. IF feed from the receiver to work. Mine is now set up with my HQ-160, prior to that it spent several years attached to a TMC GPR-90. My GPR-90 now has the matching TMC SSB adapter which has an extremely sharp filter in its 17 Khz. IF section but I often miss the versatility of the HC-10 now when using the GPR-90.