[R-390] paper capacitors

[Roger Ruszkowski]

Hi

It’s not just the paper caps that people are replacing. “Re-capping” the radio 
seems to extend to every single cap anywhere and everywhere inside the box.

Bob

---------------------------
Bob,
 
You are right.
Other than the beauties and that acid dripping one of a kind cap in the audio deck,
or the electrolytic multi section power supply filter caps,
the rest of the caps are just fine.
 
First we scare all the new comers with the C553 1st IF stage blocking cap and the mechanical filters then:
I think folks see the mess under the electrolytic in the audio deck.
Or find a brown beauty that is cracked.
Or have the big power supply electrolytics leaking and think every thing is suspect.

And just think every thing needs rework and replacement as part of the maintenance
needed to get a neglected receiver back into good operating condition.

I hate to touch the first RF stage but it has a filter cap that should be changed
and I replace it with the same value. I am not about to try and re-engineer the stage.

So many of the silver mica caps and the trimmer caps are doing just fine as is.
There is no reason to re cap a working VFO.


I ask:
Has any one done one of these full re caps and gotten more than 30 to 1 signal to noise ratio from the IF and
audio deck with 150 micro volts in?
Has any one done one of these full re caps and gotten more than 20 to 1 signal to noise ratio from the full
receiver end to end with 4 micro volts in?

Are there benefits to be gained from the effort beyond the cosmetic looks of the under side of the deck?

Today we read that a cap only lasted 10 years. How can we claim that a full recap will give us assurance that we
will not be troubleshooting and repairing failed parts sooner than if we had not done a full recap?

Roger Ruszkowski  AI4NI