[Boatanchors] If it ain't broke, don't fix it!

[Dale Parfitt]

I am with Jim,
I would not touch the NPO variables or any other cap (except paper and
electrolytic) until you have an opportunity to verify operation and specs.
Dale W4OP

-----Original Message-----
From: boatanchors-bounces at mailman.qth.net
[mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of JAMES HANLON
Sent: Saturday, March 5, 2022 7:19 PM
To: boatanchors at mailman.qth.net; k4to.dave at gmail.com
Subject: [Boatanchors] If it ain't broke, don't fix it!

Dave,

Regarding your plans to replace fixed and variable capacitors in that VF-1,
I would strongly suggest that you power it up and try it out before you go
about replacing any parts.  My two VF-1s are still running happily on their
original components.

I know there are folks who routinely replace all of the resistors and
capacitors in an older transmitter or receiver before even turning anything
on.  But it has been my experience with more than 40 receiver and
transmitter restorations that blanket replacement of Rs and Cs is usually
unnecessary overkill.  I've had only four receivers where I found it
necessary to do anything but occasional part replacement.  My SP-600
Hammarlund Super Pro was originally built with those notorious "black
beauty" tubular capacitors which all failed (shorted) shortly after I
acquired it in the 70s.  My BC-348M had a batch of molded paper bypass caps
all of which failed early in life, they would swell and burst.  I have a
BC-453 Command Set receiver in which most of the canned bypass caps have
failed shorted - Western Electric must have gotten a weak batch of caps when
they built that receiver, because my Western Electric BC-454 and Colonial
Radio BC-455 from the same era are still working well
  on their original Rs and Cs.  And all of the paper bypass caps in my
Hallicrafters SX-43 reached end of life.  That receiver had considerable
interior rust, suggesting that it must have been stored in a high humidity
environment for a long while before it came to me, probably the reason for
the demise of those caps.  I have other sets that date back well into the
30s that are still running on their original set of Rs and Cs, National
SW-3, FB-7 and FBX receivers from 1933 and NTX30 and NSM modulator from 1938
for example, Hallicrafters SX-28 from 1941, RME-69 and RME-70 from 1941,
just to name a few.  My original novice receiver, and HRO-50, which has been
in the family since the summer of 1950, is still running on its original
components.

So, except for some parts which have a reputation for fairly short life like
electrolytic filter capacitors and black beauties, a good general rule is,
"If it ain't broke, don't fix it."

Jim, W8KGI
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