1948 Westinghouse H-1821 (H-182) Issues

[vortalexfan]

Hello everyone I had bought a little over a year ago a 1948 Westinghouse Model H-1821 AM-FM Bakelite Radio that for some reason isn't making a sound, its not picking up stations or anything and all I get out of the speaker is a quiet low pitched hum that doesn't change with the volume.

I posted about this on another antique audio forum and they seemed to think it was the output transformer was bad (which I had confirmed their suspicions when I touched a screwdriver to the volume control and I didn't get a hum out of it) so I ordered an ouput transformer and some new capacitors for the radio and they should be coming next week sometime.

Anyways, another holdup I have with this radio is that this radio had installed from the factory a 50/50 MFD @ 150 WVDC and 20 MFD @ 25 WVDC filter can cap in the radio for the filter caps and I was going to replace the old ones with a 47 MFD @ 250 WVDC caps.

Some of the people on the other antique audio forum were under the impression that the caps that were installed in the radio from the factory were too big for the radio and should of been 40 MFD rather than 50 MFD and so I'm wondering what you're guy's opinion is on this matter?

Thanks for your help.

[old_tv_nut]

The tolerance on electrolytic capacitors for TVs and radios is usually much larger than 20% on the plus side. Typical consumer parts tolerance would be -20/+80%. Usually the only concern in design was that it not vary too much on the low side, which would increase hum. So, even if the originals were oversize, I think 47 uF will be fine to replace the 50s, especially if you use tighter tolerance units, like +/- 20%.

The 20MFD@25v should be replaced with something closer to both its specified capacitance and voltage (but not lower).