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1500 volt cap in Philco 630 ??????? - Printable Version

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1500 volt cap in Philco 630 ??????? - Dan Walker - 12-21-2012

I am recapping a Pholco model 630 and I ran across this cap .1@1500.v test .. Since I am not very good with schematics I can't tell you where it is in the circuit.. I do not find any values anywhere that high on the schematics.. Am I safe with a 630 volt cap?
Thanks,,, Dan[Image: http://i318.photobucket.com/albums/mm405/danwalker45/philco1500voltcap005Medium.jpg]


[Image: http://i318.photobucket.com/albums/mm405/danwalker45/philco1500voltcap003Medium.jpg]

RE: 1500 volt cap in Philco 630 ??????? - codefox1 - 12-21-2012

Well here is the schematic I think.

http://www.nostalgiaair.org/PagesByModel/811/M0013811.pdf

Off hand can't think of why you need this part replaced, but easy enough to get them. All the other waxies and electrtolytics need to be changed out, and might as well do the carbon resistors as well while you are at it. Long term stability will result.

RE: 1500 volt cap in Philco 630 ??????? - Dan Walker - 12-21-2012

Thanks for the reply Codefox1.
. I am changing out all the caps.. This particular one was put in by someone else and I think that they only had a 1500 volt cap at .1Mf so they used it..
My question was do you think I can use a .1@630 ?
I have the schematics and there are not any caps with a voltage of 1500 in the parts list.
Dan Walker

RE: 1500 volt cap in Philco 630 ??????? - Arran - 12-21-2012

It's a capacitor on the cathode of the #78 IF amplifier tube, it's in parallel with a 400 ohm resistor, a 630 volt .1 microfarad cap will be fine there, in fact a 200 volt one will be fine there, there is no way it will ever have 1000 volts across it.
Regards
Arran

RE: 1500 volt cap in Philco 630 ??????? - morzh - 12-21-2012

Dan

What makes sense for you to do when pos1ting these kinds of things is to point where exactly in the schematic the part is. It is easier for you to trace it than it is for us.
Once you do, we will try to take the best guess as to the necessity of using this part.

I can only think of one place where a part with such voltage rating would be used, but it is not there. It is the power filter cap, and in your case they used 0.015 uF, not 0.1uF.

These caps should be Y-rated and in olden days when that was not available, the voltage as high as possible made sense, but even then they did not use the 1.5kV rating for it.

(BTW when recapping DO replace those, position 69, with true Y-rated caps, the value does not matter muich and 10nF is just fine).

RE: 1500 volt cap in Philco 630 ??????? - Dan Walker - 12-22-2012

Thanks for the information I did put a.1@630 in there and it works fine..
As far as reading schematics is concerned,it's no too bad but when i get into the chassis and start looking around it is quite confusing and especially on this radio there is not much room
. I just do the best I can
and I am gratefull for the help I get on these forums. I have learned so much but some things are over my head because I have no training and have learned all this from the forum.
Thanks again Dan