"ken scharf" wrote in message
. ..
Tio Pedro wrote:
"ken scharf" wrote in Well the plug
in coil stock used by W6TC are also unobtainium these days
too. It IS possible to by raw polystyrene tubing of the right size, and
glue onto bases from dead tubes, or tube base plugs (both of which are
available from time to time). The APC variable caps are getting rare
these days, but good quality ceramic trimmers would sub and these are not
TOO hard to find.


The APC caps (silver plated brass are needed for the LO coils) are
still available. I've read that over one million a month were produced
during WWII. How true that is, I don't know, but it was on a webpage
dedicated to the history of Hammarlund. You have to shop around,
but I've picked up a few dozen for around two bucks each.

The National polystrene coils were becoming scarce by the time
the last HBR ran in QST. Bill (exray) uses Garolite XXX tubing
(phenolic) for his plug in coils; a bit pricy for my tastes. Ted's
coils had Qs of around 150 or so.

I'm going to try using fiberglass tubing--fortunately I have the
poor ham's Q-meter (Heath QM-1) to verify the effectiveness of that
material. A kind soul sent me a few dozen expired tubes to salvage
the bases from. There's always plastic pill bottles, they've been
tried and pass the Q-Meter test.

I have a bunch of turret tv tuners with the removable strips and also gave
thought to building a receiver similar to the HBR's but with toroid core
coils switched in the tuner strips. I don't know if the toroid cores were
available to W6TC and if he would have used them.

W6TC went through great pains to eliminate drift in the LO coils,
I don't know if toroids are the best choice for oscillator coils.

I'm sure you're familiar with the turret tuner in the RCA
TW-2000?

I also have a dial drive from an HRO receiver if I ever get the desire to
build something even more antedeluvian!

Now you're talking!!

Pete