Wax caps with black circle at one end.

1/5/2013 1:47:58 PMJ-F

It's been a while since I have not restored a radio, I'm a little lost for now.

I have 2 types of wax caps in my radio:

One type look to be polarized, for example:
.005MFD 600WVDC with a black circle and "negative" on one end.

Next type look to be not polarized, for example:
.005 125ACWV with a black circle and "outside foil" on one end.

What means W in WVDC and ACWV? Outside foil?
Can I replaced all these with 630V metalized poly film capacitors?

Thanks a lot!

1/5/2013 2:26:42 PMWALTER FROEHLICH

W IS FOR WORKING VOLTS DC.THE AC CAP IS USED FROM THE AC POER LINE TO CHASSIS.YES YOU CAN USE THOSE CAPS.I HAVE NEVER ENCOUNTERED ANY PROBLEMS DOINGSO.

WALTER-W2WIQ

:It's been a while since I have not restored a radio, I'm a little lost for now.
:
:I have 2 types of wax caps in my radio:
:
:One type look to be polarized, for example:
:.005MFD 600WVDC with a black circle and "negative" on one end.
:
:Next type look to be not polarized, for example:
:.005 125ACWV with a black circle and "outside foil" on one end.
:
:What means W in WVDC and ACWV? Outside foil?
:Can I replaced all these with 630V metalized poly film capacitors?
:
:Thanks a lot!
:
:

1/5/2013 3:38:40 PMDoug Criner

It was once thought that the outside foil of film caps should be connected to the higher or lower voltage, I never remember which. But the idea is obsolete, and modern caps are not so marked.

If you encounter a cap with the black ring, it is old - best to test it before using it.

1/5/2013 5:15:42 PMLewis

:It was once thought that the outside foil of film caps should be connected to the higher or lower voltage, I never remember which. But the idea is obsolete, and modern caps are not so marked.
:
:If you encounter a cap with the black ring, it is old - best to test it before using it.

The ring meant "outside foil", if the cap were to be used as a bypass of some sort, connecting the ring to ground would provide more shielding from hum. The concept didn't last.

Sort of the same thing with "Working Volts DC", the cap would test ok at a higher Voltage, but was designed to work at the rated value. Just a passing fad for a while.
Lewis
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