[davemc]

I am restoring a Philco 118 cathedral. http://www.nostalgiaair.org/Resources/125/M0013125.htm

The question relates to restuffing capacitor 46 (2@300v, 1@350v, 1@350v, 1@450v). I am concerned that the 1 and 2mfd 630 volt caps I have in stock will be too large for restuffing this capacitor. What have other restuffers used? I am concerned about using electrolytics since RF is involved, but they are much smaller and restuffing will not be an issue. Another idea was to use and electrolytic with a 0.1mfd film capacitor in parallel. I suppose I could also shop around (Mouser etc) for film capacitors at lower voltages, or perhaps look for radial type film capacitors, which seem to be smaller than axial types. I just hate to pay shipping charges on a few capacitors when I have the correct values in stock.

Thanks in advance for your help!

[morzh]

RF is not involved here in the 46 case. And actually in the case of another Philco a triple electyrolytic was used (forgot which - maybe 18, that I restored). These are low pass filters or decoupling and electrolytics are quite good at it.

Any cap will do. Of course at these capacitances iy may be easier to find film ones, buit they are quite large and el'ectrolytics will be much smaller. I would use them.

[Arran]

Given some of the voltages involved like 300 and 350 volts you should be able to get away with using 400 volt poly film caps which may be more compact, other then the 450 volt section of course. They are bypass caps so surge voltage on power up is less of an issue.
Regards
Arran

[davemc]

When I dissected Capacitor 46 for restuffing, it looks to me like it is a four-section electrolytic. There is a thick common foil, and individual thick foils for each section. The separator between the foils is a thick moist layer that looks like cheesecloth and paper. It is MOIST, not dry. Most paper caps that I have seen use thinner foil and wax paper separators - and they are dry.

Does anyone know of any reason I cannot simply use 4.7mfd @ 450 volts for all four sections?

[marty]

Hi All;
Davemc, when I look at the schematic, none of the number 46 caps are going to the same place or line..
If you had the caps connected at four or five different places but electricially connected to the same part of the circuit, then you could add all of the caps together to make one larger cap..
But, as near as I can find only three of them and they are attached to different circuits, then "no" you cannot add all the caps together..
The ones at 300 and 350 volts, since they are by-pass caps can be replaced at a lower voltage than the one at 450 volts as Arran has already stated..
But, the 450 volt one needs to be replaced with as high of a voltage rating above 450 as you can get..
THANK YOU Marty

[davemc]

I was proposing to use FOUR SEPARATE 4.7 MFD 450 volt caps, since I have four small radials in stock and they will fit inside the can. In other words do I need to order SMALLER values or will larger values work.

[morzh]

Actually in these cases I think larger values will work just fine.