[Eric]

Some of the paper caps are rated 800 DCWV all I have are rated 630v am I safe in using them?
http://www.nostalgiaair.org/PagesByModel...014995.pdf

Eric

[Radioroslyn]

The copy is pretty awful but I think you'll be OK. The only two I can think of that may require a high voltage rating would be at the plate of the output tube and maybe the plate of the rectifier. Generally 630v should be fine and have used them many times there with out an issue.
GL
Terry
ps on the output tube if the cap goes from the plate to ground you can rewire the ground side to connect to the screen grid. This will drop the volt across that cap. You also can play with the value to increase amount of highs you hear from the speaker. The smaller the cap the more high it will pass. Start with a .002 and go up from there.
Enjoy

[Eric]

Terry
The plate on the 35L6 is 96v there doesn't seem to be anything over 120dc there are 4 caps with the 800v rating they are C1,3,4,10 and yes the print is bad go figure I'm missing four volumes of riders 3,15,18,19 so I had to go to Nostalgia. They had a 50L6 for the output but I had a 35L6 so I swapped it. Going to the Lexington KY show this weekend maybe I can score another volume or two.
Eric

[exray]

Often times a high voltage cap was specced because it had lower leakage than a low voltage capacitor. This would be the case with C4, C3, C10. Not an issue with modern caps.

I'm not seeing C1 but C11 indeed needs to be 630 or greater. Radioroslyn's recommendation often helps but this cap is already tied to the screen. A 630 volt isn't going to just blow up - in fact it may last forever since modern caps are so much better than their predecessors.

[Eric]

C1 is off the Loop antenna, I always use the 630v caps to replace the paper caps. Your explanation makes sense to me. Thanks
Eric

[exray]

Aha, yes I now see C1. Another case of being specced for leakage rather than voltage. RCA was GOOD (bad) for that!
630vdc cap will be fine. 50v disc would be fine for that matter

The only critical one here voltage-wise is C11. As I said, 630 may go forever but to explain the "correct" thing you may want to consider going higher. There can be some very high audio AC spikes during thundercrashes, etc. In the old days that meant a shorted paper cap which in turn could take out the audio transformer. Modern caps are much more resilient. If a strong spike were to 'punch thru' a layer of dielectric they will self-heal and clear any short. I (and others) have played with these caps and they really do what they say. I once drilled multiple holes in one in this location and couldn't make it short out!

If you want to be 100% safe you could use two .047/630v in series. That would give you .023 @ 1260 volts and you'd never have to give it a second thought! Or, .02@1000 vdc isn't hard to find in a ceramic disc capacitor if you're shopping anyway.

[Arran]

I think C1 is maybe 600 volts, I can't see why an 800 volt cap would be needed there at all. On occasion they will use a high voltage cap across the primary of the output transformer but I've only seen this in an AC set with much higher plate voltages then the usual 90-110 you see in an AC/DC set. I noticed they used a 700 volt job on the coupling cap for the volume control, C7, that was for leakage, the plate voltage on the 12SQ7 is maybe 60 volts tops, no where near 700 volts.
Regards
arran

[Eric]

All very good info I will probably leave as is but I do have to restock .01@630 caps and some other things so I may order some 1KV caps just to have around.

[Paul Philco322]

Although a Broadcast Band only set it is a nice one, sorta Western looking numerals on the dial glass and a tone control. A fine player, I have DX'ed with mine with pretty good results. I had to do the cabinet over on mine and of course the cat had to slip off the top of it and scratch the daylights out of it, gouges actually. Oh well, still have the radio and the cat.

Good luck with yours.

Paul