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Joined: Jan 2012
I'm recapping a F-1740 that was mostly unmolested except that the 3 section filter cap was missing. The schematic shows a 20mf off the 7C5 output tube, and a 15 mf on the B+ and 10mf to the speaker coil. Unfortunately, the schematic doesn't give the voltages, only the mf values. (1940). I suspect the 15 and 10 are around 350 volts, don't know about the 20 mf. Can somebody give me a hand with what voltages correspond to which mf values? The original part no is 61-0089. Thanks
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City: Moundsville
State, Province, Country: WV
Here's a post on another forum regarding the caps:
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Carl
Northern Panhandle, WV
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Excellent! old part nos come in handy, thank you
Posts: 7,213
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Joined: Dec 2009
City: Roslyn Pa
Hi and Welcome to the phourm!
You can't go wrong by putting a cap in there with a higher voltage rating. You could use 450v caps in place of the 350v jobs. The only issue may be size. You mention that there is a cap off of the 7C5. If it is connected to the cathode the voltage rating is going to be much lower as there isn't much voltage there. Something in the 35-50v range will be fine. Cathode will have about 10-15v on it.
GL
Terry
ps When you replace #76 it needs to be a high voltage job at 1.5 or 1.6KV. If it goes bad it will take the power transformer and chopper (vibrator) with it.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
