[R-390] looking around for r390-a

[Barry Hauser]

>Barry W. wrote:

<snipped>

> And, it was the
> cleanest radio I've ever seen. Every bit of it looked like it came off of
> the line yesterday. This radio had to have been preserved somewhere. Wire
> bundles were clean and shiny. Not a speck of dust could be found anywhere.
> Also, there was not a drop of lube on any of the gears. The best I can
tell,
> this radio had the TMC mod done to it and it has the tapped holes on the
> back of the chassis for part of mod that I've seen elsewhere. It has the
TMC
> mod tag on the front panel. It came with the Utah plate with top and
bottom
> covers. It also came with the black meters. It has a 67 EAC chassis, power
> supply, and AF deck. I think the IF and RF decks are EAC too due to
> manufacturing looks and peculiarities when compared to everything else.
> Funny thing is that it had a S-W tag on the front.

I've got three like that, but they weren't clean.  Two work, one is missing
its PTO.  All have that TMC mod with the little box on the back panel with a
solid state PC board in it, extra labeling on added bnc connectors, etc.
They're somewhat mysterious.

>
> I haven't done much to the radio yet. I keep putting off the work as it
has
> major problems everywhere. Low sensitivity below 8 mHz. Calibration points
> are off just about everywhere. I tried to align it with a friend a few
years
> back and it wouldn't align past the first mixer. I forget the details at
> this moment, but I have my notes in the manual. I figure that this one
needs
> to be recapped everywhere and everything inspected closely.

This reminds me of something Dave at Fair used to tell me.  Every now and
then, he'd come across a really clean R-390A, but he couldn't get them to
work with any degree of module swapping.  I suspect the following:

1.  They failed early and got put aside, or were mothballed long enough for
lots of caps to go bad.
2.  Faulty wiring harnesses, and again, assided.
3.  "NOS/NIB" units of the fabled grail stories.  But, the realities are
that an original unused, untouched for 40 years R-390A is unlikely to work,
and worse, will do damage to itself if powered on recklessly.
4.  Unit that was on the defective pile and not yet repaired when they
started phasing out, or buried in the repair depot.  Evenutally got
surplussed out "as found".
5.  Somebody messed around with it, scrambling the works with difficult to
find wiring errors and may have even tried to align the set by "ear".
6.  Attempted removal of mod.

Well, something like those.  The two that I have like (with the mod) were
laced with puffy white corrosion here and there.  Looked bad but it cleaned
up as if it were an outside job or not really corrosion.  Both went
operational with very little work.

I've seen a number of R105A's -- the Collins aircraft/autotune receivers --
that, inside, look like they were never used, but have odd wiring
discrepancies vs. the manual and don't work.

Yup, ya' can't tell by lookin'.  And, what's odder still, is a depot dog
fugitive from St. Julien's Creek has a shot at WOA -- working on arrival.

But the real reason is probably this:  Your's is missing it's Knights of the
Templar, Guardian of the Grail dead spider.

Barry