Heathkit SB-102 Question

[Raccoon]

I posted this previously , but I believe I posted it in the wrong area ... so I'm reposting it here .

I have a Heathkit SB-102 that I run with the HP-23(B) power supply . The SB-102 has had some updating done to it on the inside ... but not everything has been updated . I've talked about this radio here on the forum before , and for the most part it's a pretty good radio , both cosmetically and performance wise . But , it does have one issue that I can't figure out . Sometimes it can go days without it acting up , and other days it will do it quite a bit . I'll be on one of the bands listening , and then all of a sudden it just cuts right out , there's no audio , and it has a quiet hum . Sometimes I can turn it off and back on , and it fixes itself .... and other times I just have to turn it off and walk away .

Does anyone have any idea what might be causing this (maybe a cold solder joint) , or a good idea as to where to start looking for the problem ?

 

[nomadradio]

Relay.

Dirty tube socket, or socket contacts that have lost their spring temper.

Funky tube. I'm accustomed to holding the tip of the small tubes stationary while "flicking" the side with a fingertip or plastic tool handle. A tube that makes noises or makes the signal rise and fall with this sort of test has internal structure faults that can cause intermittent stuff like that. Turning the radio off will cycle the temperature of the tube's components down, then up. Not so different from tapping on it. The tube sockets used with printed circuit boards will have a lot more failures than the ones found mounted to a metal chassis hole. Well, some of them do.

73

 

[Shadetree Mechanic]

My Sonar 2340 did the same thing. Found the wire was broken at the antenna socket. It was still there and looked good until I looked really close.