"ablebravo" wrote in message
ups.com...
have an 'audio filter' package that sits between the
output of 1rst
audio 6c5 and a tone control. shot; needs rebuilt. 1940
national.

am looking at mouser for suitable chokes. there are
waaaay too many
choices... vintage electronics did not have any
suitable....

what is best generic part for this application? ie i need
to narrow
down 100's they offer to what i need in some way. was
looking at
fastron epoxy mcc/n series. can't find the exact values,
either. can
get w/in 20-30 MH. how critical?

schemo gives two 'filters' (choke/inductor) valued at
175MH and
360MH. also in the package are two mica caps .006mfd and
.011mfd.

the values seem hard to find for micas -- is 'orange dip'
substitution
for this ok? i can turn up these micas up on mouser but
at $6-25 (!)
each, depending on specs.
thx much all help.
ab

Are the caps specified as mica in the parts list?
There were actually two kinds of mica caps, one was the
familiar silvered mica where the "plates" of the capacitor
are plated onto the mica dielectric and the "stacked" mica
using foil. The former are the familiar very stable type the
latter were not so stable but could be made for relatively
high voltages. I suspect these are of the latter variety and
modern metalized plastic caps are better and more reliable.
BTW, despite reputation for high reliability of
silvered mica caps the older molded body type seem to fail
at fairly high rates. I just went through restoring an
SP-600-JX 17 which was in very good condition but have had
to replace at least half a dozen or more silver mica caps
because of instability. This is not to say they were bad,
after all, they are more than fifty years old.
You may be able to salvage the inductors depending on
what has happened to them. If the leads broke of the
terminals you may be able to simply resolder them. Its
certainly worth a try.


--
---
Richard Knoppow
Los Angeles, CA, USA




--
Posted via a free Usenet account from http://www.teranews.com