CR-88/AR-88 Piston Capacitors
 

In a recent restoration project I noted that some of these in the RF
section, mainly on the three highest bands are intermittent. i.e. I tap on
one a few times and a previously dead band comes alive. It seems to last but
I'd sure like to clean these up. Can someone describe the construction? They
appear to be a slug (Made of a dielectric?) inside a ceramic tube with metal
end caps. Should I use deoxit around the screw and twist a bit? I'll
probably clean these in conjunction with an rf alignment.

Nice receiver BTW stable with great audio.


TIA Tony WA6LZH

Its been over 40 years since I played with one but I don't recall the
pistons being a problem back then but 40 years can do a lot, self evident.
Have you made sure it's not something else. Try freeze spray and putting a
hot soldering iron tip near the piston caps to confirm that they're the
problem.
73
Hank WD5JFR
"Tony Angerame" wrote in message
...
In a recent restoration project I noted that some of these in the RF
section, mainly on the three highest bands are intermittent. i.e. I tap on
one a few times and a previously dead band comes alive. It seems to last
but
I'd sure like to clean these up. Can someone describe the construction?
They
appear to be a slug (Made of a dielectric?) inside a ceramic tube with
metal
end caps. Should I use deoxit around the screw and twist a bit? I'll
probably clean these in conjunction with an rf alignment.

Nice receiver BTW stable with great audio.


TIA Tony WA6LZH

Thanks for the reply Henry. Good tips. What I found was that after
taking the
locking nuts off I could see what appeared to be lubriplate on the
shafts and rods. I cleaned them up with contact cleaner followed by
deoxit. Now they slide and work well. It's kind of spooky to realize
that some tech way back maybe as far as WWII applied that grease. Like
a voice from the past. Are you familiar with the AR-88/CR-88? That
wasn't you with the Lubriplate was it? Just kidding.
I fashioned a tool out of some brass rod stock I had on hand (fell
behind the work bench from a previous project but that's another
story.) This radio lines up pretty quick once you figure out where all
the L's and C' are.


Thanks,


Tony WA6LZH






"Henry Kolesnik" wrote in message m...
Its been over 40 years since I played with one but I don't recall the
pistons being a problem back then but 40 years can do a lot, self evident.
Have you made sure it's not something else. Try freeze spray and putting a
hot soldering iron tip near the piston caps to confirm that they're the
problem.
73
Hank WD5JFR
"Tony Angerame" wrote in message
...
In a recent restoration project I noted that some of these in the RF
section, mainly on the three highest bands are intermittent. i.e. I tap on
one a few times and a previously dead band comes alive. It seems to last
but
I'd sure like to clean these up. Can someone describe the construction?
They
appear to be a slug (Made of a dielectric?) inside a ceramic tube with
metal
end caps. Should I use deoxit around the screw and twist a bit? I'll
probably clean these in conjunction with an rf alignment.

Nice receiver BTW stable with great audio.


TIA Tony WA6LZH

Good tips. Thanks Henry. I think I figured it out. Looks like someone
put grease i.e Lubriplate on some of the pistons. Cleaned it up and
deoxed it works fine slides nice. Have you dealt with the AR-88/CR-88
much? That wasn't you with the Lubriplate was it? Just kidding! Kind
of eery to think of someone doing that 50 years ago or more and I just
ran into it. Thanks for you r reply.

Tony WA6LZH


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