Black Beauties,
I'd replace all of them on sight.

Kill 'em all. They are junk by now, just like earlier wax/paper caps, for
any serious application.

It takes less time to simply replace one than it does to pull it out, test
it, and either re-install it or replace it.

You won't regret it, and you have nothing to lose. Unless you're one of
those vintage electric guitar nitwits who wants to find an original
"bumblebee" cap or two to provide that tasty "period" sound (i.e.,
distortion resulting from badly leaking capacitors, which certainly wasn't
what the guitar sounded like when new).

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

I had to change 100% of the micas from a BC-669D. Also, micas in some
ART-13s have also gone bad, some near impossible to get to. I don't
think many of these components were ever even dreamed of to go this
long! On the other hand, my SX-28, apparently in use almost
continuously since is was purchased, is still humming (no pun
intended!!). Hope I can get away with not doing the RF section...?
Worst B/Bs I ever saw were in a National NC-125. They looked like they
just dropped out of a bag of spoiled mussels.

"K3HVG" wrote in message
...
I had to change 100% of the micas from a BC-669D. Also,
micas in some ART-13s have also gone bad, some near
impossible to get to. I don't think many of these
components were ever even dreamed of to go this long! On
the other hand, my SX-28, apparently in use almost
continuously since is was purchased, is still humming (no
pun intended!!). Hope I can get away with not doing the RF
section...? Worst B/Bs I ever saw were in a National
NC-125. They looked like they just dropped out of a bag of
spoiled mussels.

I suspect the environment has something to do with it.
For instance, the BB's in my SP-600 were pretty awful but I
found one in a General Radio 1001A signal generatror that
looked brand new. I replaced it on general principles but it
tested good.


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Richard Knoppow
Los Angeles, CA, USA