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Philco 59c
#1

I’m working on the later version of the Philco 59c (code 121).  Schematic Link.    This chassis has been recapped at an earlier date as you can see in the photo (block caps have some terminals cut, ecap tacked in and the style of caps).  

[Image: https://www.dropbox.com/s/hddp83hjqln8ne....jpg?raw=1]

Question 1: does anyone have a photo of an undisturbed chassis bottom view so I can see what it looked like originally?  Question 2:  The bakelite block cap #19 (7762B) is listed in the parts list and on the schematic as a 0.015uF and 0.0001uF dual cap.  In the Philco Service Bulletin #289   for bakelite cap data it lists the 7762B as being replaced with a 7762OEU and the caps are 0.015uF and 0.001uF.  Is 0.0001 or 0.001 correct??
Thanks!
#2

On a closer look I think I can answer my own Question #2; the schematic actually indicates cap 19 as 1,000 uuF which would be 0.001uF. The parts list probably is in error. Still looking for an under chassis photo.
Thanks!
#3

Question#3: the voltage rating of Bakelite block cap 7762-OEU is 1200 volts. Do I really need 1200v caps for this or will the usual 630v jobs handle it?
Thanks!
#4

if it is #19, 630V is more than enough.
#5

Thanks morzh. That's what I was thinking when looking at where it was in the circuit but wasn't sure.
#6

Bob

Here's how.

1. The cap of 1000 uuF is a plate cap. The plate voltage is listed as 42V. While the tube warms up it can quickly go to maybe a 200V if this much. Worst possible is maybe 250V.
2. The oter cap should have exact same voltage.

So even 400V is plenty.
#7

Thanks, very helpful.
#8

Here's a summary of the rest of the restoration:

Not only were there a lot of caps tacked into the underside of the chassis,
[Image: https://www.dropbox.com/s/yxj9yxu7943nzb....jpg?raw=1]

but two of the block capactors were removed and more caps tacked in on the top of the chassis:
[Image: https://www.dropbox.com/s/o0awcoy1544kq2....jpg?raw=1]

Found some block caps from John Kendall's antique electronics site and restored the topside:
[Image: https://www.dropbox.com/s/42jokby5ran1zt....jpg?raw=1]

Stuffed the 8 & 4 uF electrolyic can, stuffed the remaining block capacitors and made some dogbone resistors to replace out of spec ones (yes, there is one last modern resistor peeking out of the oscillator transformer can yet to be replaced):
[Image: https://www.dropbox.com/s/5sp56chf0abf47....jpg?raw=1]
#9

Doing a fantastic job there Bob, that's the way I like them, as original as possible.

Gregb




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