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Yesterday I recapped the underside of the HV and HOT area and the
vertical convergence amp.
The latter was a disaster zone.
All resistors were way off value except a 270K in the first stage plate.
And that one appears to be the wrong value, despite being listed as 270K
on the RCA schematics! The tube has 9.3 volts listed on the cathode
with a 2.7K cathode resistor. That's 930 volts across 270K ... not right.
Sam's has 27K there. It looks like I need to change it to 27K.
And the cathode resistor in the second stage was 47 ohms ... both RCA and Sam's
have 4.7K with 20V and a 100 uF cap across it ... very reasonable.
Thus, this set much have been seriously worked on in the past. I'm going to
have to check each part value with both RCA and Sam's, a nightmare. There
are resistors and caps everywhere that have been replaced with 1950's parts
by cutting leads and twisting the new leads around them.
Oh did I mention that one lead of a cap in the vertical convergence amp
area was already broken, and when I touched the cap, the lug on the tube socket
attached to it fell off? I was able to kludge that by soldering a #32 wire
to the remaining tube pin part since it is a 7 min miniature socket.
But the bottom does LOOK perfectly neat. The previous owner (who was
a TV person and probably did it himself) did a good looking job.
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