Posts: 17
Threads: 9
Joined: Aug 2006
I've recapped my 40-180 except for about four that are wedged underneath all the mechanics for the push button tuning. The guy's who been helping with the electronics said he wouldn't mess with them; all the rest are replaced. What do you all think? Should I go ahead and attempt to remove the push-button section to get at them?
Ryan
Posts: 1,703
Threads: 55
Joined: Sep 2005
City: Evanston, IL
The caps, 20, 22, 23, 24 are all mica caps and probably are ok. Although, micas have been know to go bad now and then.
If there is any problem aligning or tacking or setting pushbuttons, then they should be replace with newer silver-micas types.
Resistor 25 (33K in the pushbutton gang area) should also be checked for out of 20% tolerance and repalced if it's out of spec, just like all the other resistors in the set for proper performance and restoration longevity.
Posts: 17
Threads: 9
Joined: Aug 2006
No, these are wax (3 x .05 and 1 x .01). I can hardly squeeze my fingers down there to move them just a bit.
Ryan
Posts: 1,703
Threads: 55
Joined: Sep 2005
City: Evanston, IL
Then, unfortunately, they have to go, if I were you. You'll regret it in the long run as you run the set over time. If one of those caps is the AVC filter (#32 maybe?), it will eventually cause AVC (read RF/IF gain) problems and reception can overload due to excessive leakage to ground or open up and cause distortion due to unfiltered audio signal modulating the front-end gain at audio frequencies or motor-boating. If they are B+ or screen bypass caps, the set can start squealing.
See if the replacement caps can be shifted to the same point electrically, but in a new/better physical location.
Posts: 17
Threads: 9
Joined: Aug 2006
Okay, thanks Chuck. That was my gut feeling but I thought I'd get a second, more qualified, opinion. Should be an adventure.
Ryan