"Michael A. Terrell" wrote in message
...

I am restoring a TS-382 Audio signal generator that is built with
all
bathtub cabs, and every one of them is bad. They were made with the
same
high acid paper that wax and molded capacitors were made with, they
are
just sealed in transformer oil. I am in the process of unsoldering the
cans and replacing the caps inside with metal film capacitors I have
to
use a torch to heat the case and cover. There is a small vent hole
that
is soldered shut. You have to find it and remove the solder first, or
it
may blow hot solder on you when remove solder melts around the edge of
the cover. Then I use a curved dental pick to lift the cover off while
carefully heating the cover with a torch. I use a small drill press
vice
with smooth jaws to hold the can, and set it on a sheet of steel. (An
old desktop PC case is good, because it has an open airspace under
it.)

Steel bath tub caps have been pretty reliable for me. Certainly more
reliable than paper or electolytic caps. I've got the chassis out of my
S-36, and I'll check those steel caps carefully.


When I started this I dug through my collection of NOS bathtubs,
and
most of them have high leakage as well. I did find one company who
still makes new bathtub, and other oil filled caps, but I couldn't
spend
several hundred dollars for new caps for one project.
--
21 days!


Michael A. Terrell
Central Florida

I only have a few NOS steel caps in my collection. I checked them a
couple of years ago, and they were good.

Anyway, oil filled steel caps were more reliable than paper caps and
electrolytics in the mid 50s and were the usual choice with cost is no
object equipment.

Frank Dresser