[Alex Pogossov]

Hello,

In 1960's japanese radio manufacturers (Pioneer, Lafayette and others)
started using disc ceramic caps in their radios and tuners-amplifiers. (AM
"stereo" dual radio receiver with a stereo amp 2x6BM8 is a trypical
example). These caps were placed in abundance for decoupling in the RF
stages. I have many of such caps in my junk box.

These disc ceramic caps can be green (manufacturer TAIYO) or mustard colour
(TDK). Diameter varies from 8mm to 18...20mm depending on value and
dielectric.

For example, one of them is marked :
..01uFM
TAIYO

Another (smaller):
..01uFP
TAIYO

Another:
..01MF
M
TDKE

I think the letter after the value ("F" or "P") is tolerance. I guess M =
+/-20%, and P could be +100% / -25% or something like that, suggesting
that some are like modern X7R dielectric, others like Z5U dielectric.

But my question -- what is the vorking voltage of such caps? 250V? 500V?
Maybe the letter is not tolerance, but voltage? Can they be used for
recapping vintage radios where upon power-up when 5Y3 warms up, the B+
voltagee reaches almost 400V?

Regards,
Alex

[GRe]

"Alex Pogossov" wrote in message
...
Hello,

In 1960's japanese radio manufacturers (Pioneer, Lafayette and others)
started using disc ceramic caps in their radios and tuners-amplifiers. (AM
"stereo" dual radio receiver with a stereo amp 2x6BM8 is a trypical
example). These caps were placed in abundance for decoupling in the RF
stages. I have many of such caps in my junk box.

These disc ceramic caps can be green (manufacturer TAIYO) or mustard
colour (TDK). Diameter varies from 8mm to 18...20mm depending on value and
dielectric.

For example, one of them is marked :
.01uFM
TAIYO

Another (smaller):
.01uFP
TAIYO

Another:
.01MF
M
TDKE

I think the letter after the value ("F" or "P") is tolerance. I guess M =
+/-20%, and P could be +100% / -25% or something like that, suggesting
that some are like modern X7R dielectric, others like Z5U dielectric.

But my question -- what is the vorking voltage of such caps? 250V? 500V?
Maybe the letter is not tolerance, but voltage? Can they be used for
recapping vintage radios where upon power-up when 5Y3 warms up, the B+
voltagee reaches almost 400V?


Although I doubt you'll find the info you're looking for,
Capsite 2009 has tons of information about capacitors.
See: http://my.execpc.com/~endlr/index.html
- Chapter "Markings" and the links therein.
- Chapter "More information", links page.

Regards,
Gio



Regards,
Alex