[Hammarlund] HQ140 - really *LOW* sensitivity

[na2x at yahoo.com]

I'm working on a HQ-140X trying to get it into working order. I've spent many hours trying to figure out what's going on with it but so far, no luck.

The radio basically works, but the sensitivity is really low on it. Yes, the sensitivity control is at max. The only AM station I can pick up is our local 50KW clear channel station. It comes in about S4 on the meter. Other than being weak, it sounds OK.

Here's the puzzle. Quite by accident, I had the aluminum cover off the variable tuning capacitors on top of the chassis. I noticed when I bring my hand near the antenna trimmer cap, the sensitivity comes way up. If I touch the trimmer cap, the radio really comes alive to the point where I think it's working as it should (if it would only stay like that). The local 50KW station almost pegs the S meter.

To me it sounds like something in the antenna input circuitry but I've traced the wires to the switch and that area, checked the antenna coils for continuity, checked grounds, and haven't found anything. Should I continue looking in this area or does anyone have any other suggestions?
 
I'm just about ready to through in the towel, I've spent way too much time on it. I really don't want to give up on this receiver, it's a nice one and it's in really good shape. 

Thanks,
Bob NA2X