Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 48-1256 electrolytic voltages
#1

Hi,
I'm working on a Philco 48-1256 radio/phono. Years ago someone replaced all the electrolytics (which then failed) with what looks like whatever they had on hand.
I need to know the voltage specs of the 40MF (C103A) and10MF (C103B). The combined C103 is part number 30-2575-12 but Rider's doesn't give any voltage values for the capacitors in the parts list. Also if possible, the voltage specs for two 15 MF electrolytics (C101 and 102). Schematic is in Rider's 18.
What is in there now is a dual 50MF rated at 150V for C103. Two unreadable electrolytics were put in for C101 and C102. These all come off the 50X6 rectifier tube

Thanks,
Mark
#2

I'd use 250 or 400 volt caps on this one. I normally just use 400 volt ones so I don't have to keep so many different ones in my bins. You can always use a higher voltage cap; the modern ones are so small that you will not have a space issue. Also, going a little higher in value, say a 20 mf to replace a 16 mf or a 10 mf to replace 8 mf is ok too. I don't like to go under the specified value of capacitance by much, to prevent hum and/or motorboating.

Hope this is helpful.
#3

Thanks for the help.
The replacement electrolytics that were used in this set seem to be 150V (at least the ones I can read) but that seemed too low to me. I have some 150V modern electrolytics (40 and 10 MF ) but I didn't want to use them without checking on the phorum first. Sounds like I should use higher voltage caps.
Mark
#4

Would you believe the original Philco service manual for the 48-1256 does not give the working voltages for these electrolytics? Icon_confused

So...using the part numbers given and looking them up in the Philco 1950 parts catalog, here is what I found.

C101, C102: 30-2575-11 - 15 uF, 200 WVDC
C103: 30-2575-12 - 40 & 10 uF, 200 & 200 WVDC

I would use caps rated at 250 VDC. You probably won't find 15 or 40 uF; use 22 for the 15 and 47 for the 40 and you'll be OK.

--
Ron Ramirez
Ferdinand IN
#5

Thank you very much for the valuable information. I appreciate it and will do as suggested.
Regards,
Mark




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
New member
Hello jeff, Welcome aboard ! Sincerely Riochardradiorich — 06:53 PM
New member
Good picture, When was it taken? You don't look in it like a guy who has a teenage son :)morzh — 06:13 PM
New member
Love the pic! I'm southern IL, so wouldn't be much help and Bob Anderson is very good on those, but lives in Chicago are...TV MAN — 05:25 PM
Philco 40-120C Filament Wiring
:thumbup:klondike98 — 04:56 PM
Philco 40-120C Filament Wiring
With these values I think you are OK; the Cmax for this tube is 40uF. Your Vbb could rise a bit, but probably not too mu...morzh — 04:53 PM
Philco 40-120C Filament Wiring
BTW, someone had replaced the original 20uF/20uF filter cap with a 47uF/33uF cap. Do you think these values are safe on ...bluecap — 04:33 PM
Philco 40-120C Filament Wiring
You're correct. I was misinterpreting the key position. I now know where it is, and things are making sense. I appreciat...bluecap — 04:29 PM
Philco 40-120C Filament Wiring
I think Morzh has a good thought. Check the key position. The under chassis diagram in the Philco info shows an “H” for ...klondike98 — 04:25 PM
Philco 630csx power cord
Yes, the third wire goes to the stud on the side and is separate from the other two. I've usually used cloth covered ...Tynwald — 03:09 PM
New member
Have you tried Alabama Historical Radio Society? They possibly could recommend someone. I remember a name of Dee Hanes...morzh — 03:08 PM

[-]
Who's Online
There are currently no members online.

>