Philco 38-7 Electrolytics replacement - Printable Version
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Philco 38-7 Electrolytics replacement - LarryD - 06-13-2026
Just wanting to know if it's okay to replace the 8uf/4uf can capacitor with a 10uf & 5uf 500V caps.
Also needing to know what the value of the other can cap is. The printing on the can is covered in tar and the schematic does not specify what it is.
Thank you!
RE: Philco 38-7 Electrolytics replacement - morzh - 06-13-2026
Can you give the link to teh sch? The one I am looking at has the rectifier caps as 25uF and 8uF; then #11 is 4uF.
if these are the ones, the 11A and 11, yes it is OK.
RE: Philco 38-7 Electrolytics replacement - LarryD - 06-13-2026
Here's a schematic: https://philcoradio.com/library/download/service%20info/wiring%20diagrams/vol2/split/Part37-Philco%20Wiring%20Diagrams%20Vol.%202.pdf
RE: Philco 38-7 Electrolytics replacement - morzh - 06-13-2026
Yes the same.
So, what I said before.
RE: Philco 38-7 Electrolytics replacement - LarryD - 06-13-2026
I guess I should also replace the .015/.015/25uf ceramic bodied multi capacitor as well. What voltages should the replacements be?
RE: Philco 38-7 Electrolytics replacement - morzh - 06-13-2026
Can I suggest, when you refer to a part, please give the reference designator?
RE: Philco 38-7 Electrolytics replacement - LarryD - 06-13-2026
I'm referring to schem.# 47 or part# 3793DG.
RE: Philco 38-7 Electrolytics replacement - glyphmon - 06-13-2026
For all the paper capacitors, including the two inside that C47 bakelite block you asked about, 630V is what I've gone with as a safe, standard, commonly available voltage, though it's not electrically necessary to be that high.
Guide (by Morzh) about restuffing those bakelite blocks in case you want to go that route: https://philcoradio.com/library/index.php/shop-talk/techniques/bakelite-capacitor-rebuild-without-desoldering/
I believe Morzh has recommended to me in the past that the first electrolytic being 500V with everything else being 450V. I'm new to this so which one is first vs not first is not a detail I'm yet able to tease out, so I should think 500V for any electrolytic should be safe.
Best wishes,
Roy
RE: Philco 38-7 Electrolytics replacement - morzh - 06-13-2026
Roy
450V is allowed there; that does not mean you have to. You could use 500V and, this said, you could benefit from buying in bulk.
Larry
You are referring to the input filter; first of usually the backelite block does not contain any electrolytic caps. THis one shows 0.015uF x2 and 25uF. I do not see any third #47 which is 25uF in the sch.
Also they are not ceramic. Were they ceramic, they potentially could've been left there (though they were not Y-rated).
So, it is likely just two 0.015uF and could be replaced by 0.01uF Y1-Y2 rated caps (I gave someone link here 2 dys ago to Mouser's search result).
RE: Philco 38-7 Electrolytics replacement - LarryD - 06-14-2026
Yes, it is not ceramic, but bakelite. That's what happens when you stay up too late and don't have the chassis in front of you when you ask a question, my bad....
I do have some .01uf 600V caps I can put in place of the original .015uf caps. So far, it looks like I have all the caps I need to re-cap this radio. Now I just have to get a free evening to get to doing it. Thanks for all your help so far.
Larry
RE: Philco 38-7 Electrolytics replacement - RodB - 06-14-2026
Larry,
Cautionary note. If they are not Y1 or Y2 rated Safety Caps they may short if they fail. This results in unpleasant odors emanating and unwanted fireworks. Safety caps are called this because they fail open.
RE: Philco 38-7 Electrolytics replacement - morzh - 06-14-2026
In some cases there is no odor, but then you touch the chassis while standing on wet concrete...
RE: Philco 38-7 Electrolytics replacement - LarryD - 06-14-2026
I have a 24.6uf 450V cap I'm planning to put in place of the single can cap. I will get the safety caps for the bakelite block instead of using what's on hand.
Yeah, the part list that listed 3 parts in the bakelite block threw me off. I was wondering how they stuffed any size 25uf cap in that little block.
I have a bunch of other radios that I haven't fixed up yet, so I'm looking forward to getting many of them going this year.
BTW, what's a good voltage rating for the safety caps?
RE: Philco 38-7 Electrolytics replacement - morzh - 06-14-2026
A 24.6uF? Is this what is written on it?
RE: Philco 38-7 Electrolytics replacement - RodB - 06-14-2026
Safety caps are rated Y1 and Y2 for transformer primaries and X1 or X2 for across the line AA5 type radios. Some are combinations. I buy the X1-Y2 then I'm covered. Just two voltages to worry about, 120 and 220, it's built in to the designation. Since you live in the US, either one is good.
Yeah Mike, I just put in an order to Mouser and it has ten 24.6 mfd caps.