Richard Knoppow wrote:
"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
I had a SP-600-JX-14 several years ago that came from a Western
Electric monitoring station on the east coast. It came with a SPC-10
and a speaker panel. I had been on continuously for 24/7 for many, many
years other than for retubing and check-ups. It had "ALL" the original
black tubulars. None were split nor leaky. I used it for a couple more
years then sold it. I have had twenty SP-600's pass through my hands
over the years, most of those black tubulars or gray ones were leaky
and/or split open. The enviroment in which it was in and either in use
or sitting turned off would also make a difference.
In recent years the silver micas are now showing up bad, probably due
to silver migration. The avc chain on the SP-600's at this point in
time should be looked at closely. Many of them are bad.
YMMV