JA Boatanchors? Wow...

[Steve Harrison]

I asked Jeff, KH2PZ, about the "vintage solid-state" list:

>On Mon, 22 Jun 1998, Steve Harrison wrote:
>
>> At 05:40 PM 06/22/98 -1000, you wrote:
>> >That gear is classified as "vintage solid state," not BA.
>> >It has its own e-list.
>>
>> Jeff, where is that list and how to subscribe? TNX, Steve Ko0U/1

But:

>Hi Steve,
>It's called VSS and I just can't recall what site it resides on.
>You'd better ask the BA list about that!
>73,
>Jeff

So: anyone know about the VSS list? No, I'm not abandoning real BA's; it's
just that I grew up during the age when the first solid-state radios were
finally beginning to yield some decent performance, and so have some fond
memories of various attempts by a few of those early radios to replace REAL
radios. Wouldn't mind peeking in on that list to read what's said about
them today!

BTW, I spent most of the weekend on what, initially, appeared as a lost
cause: my newly-acquired, 1945-vintage KE-23A receiver developed horrendous
scratching and intermittent noise on Band C. Eventually, I decided it had
to be in the plate coil of the RF amp or the grid coil of the mixer. Sure
enough, as I removed the old shielded coil from the chassis, it became
apparent that this problem had been worked on by somebody else before. It
eventually turned out that the RF amp's (6SK7) plate coil was open. For
Band C (5.0 to 16 MHz), this coil is what seems to be around 40 or 50 turns
of probably #34 AWG magnet wire wound in a pi form about 1/8" wide with the
wire stacked up a little higher than that. It didn't appear too formidable
to rewind the coil; but it sure didn't look like any fun, either! I had
serious doubts that after rewinding the coil, I would ever get Band C to
track on the dial again.

After unwinding the outer 33 turns (and the bakelite form was beginning to
appear under the coil, meaning there were only another dozen or less turns
left), the broken wire ends finally appeared. They had been lying against
the bakelite coil form where I could now see that there was a little spot
of green cupric corrosion on the form. Apparently, something had gotten in
there and eaten the wire (my guess is soldering paste, which I found on
quite a few original solder joints in the whole receiver), eventually
breaking the wire but leaving the two ends to make erratic contact. I found
some rubbing alcohol and with a Q-tip, carefully tried to wipe away any
remaining corrosive paste (or whatever it had been).

To repair the damage, I simply tinned the ends of the wires about 1/8",
soldered them together, drove out to buy some polystyrene model cement,
then carefully began rewinding the coil, locating the soldered joint just
outside the coil itself so the joint would not abrade the wire insulation
inside the coil as temperature caused expansion and contraction. About
every 1/2 turn, I stopped and applied a very small dab of cement to hold
the wire in place. After awhile, there was enough wire and cement in place
that it was only necessary to place dabs maybe every turn or two. The idea
here was to use only enough cement to hold the wire in the handwound pi
coil form so that if needed later, it could still be unwound by breaking
the very small dab or layer of cement. I found it impossible to keep track
of the number of turns as I rewound, but decided not to worry about it as I
couldn't do any better. It was also impossible to exactly duplicate the
original machine-wound symmetry of the back-and-forth wire within the coil;
but I did the best I could.

Finally, the coil rewound, I reassembled the whole transformer, reinstalled
the stuff removed to get it out, fired up the radio, corrected a couple of
rewiring errors (for example: I initially connected the B+ to the grid of
the mixer and the mixer's grid leak resistor to the RF amp plate! Somehow,
I drew the wrong connections in my notebook as I disassembled the
transformer; that poor 6K8, I wonder how much current it drew?), and
finally Band C came back to life with none of the scratching, hissing and
popping. What's more, the sensitivity appears to be fairly even across the
band, indicating that the coil is, indeed, still tracking fairly closely!
Gave me a good feeling of satisfaction, it did.

But I'm sure glad it wasn't one of the 455 kHz IF transformers or BFO coil
that went...

TNX, Steve Ko0U/1

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