On Wed, 7 Sep 2005 01:32:44 UTC, Chuck Harris
wrote:

kh wrote:

Speaking of Gaithersburg, if you google for "R-9xx Collins", you'll
get a page that discusses the fabled R-390A that had a factory built
LED digital display in place of the Veeder-Root mechanical counter.

About 30 years ago I saw one of these for sale at Gaithersburg. It
wasn't a homebrew job, the vendor had the manual for it, I recall
that he fanned it and showed folks the circuit diagrams. That's
diagrams, plural.

So you Collins types, a piece of trivia, the "R-9xx" is real. I was
"this close" to it. I wonder where it is today. I bet that an
R-9xx would make an SX-88 or KW-1 look cheap.

One of the ways I make a living is designing prototype equipment for
the US Army. I have in the past modified items that were in the usual
military supply stream to add features that were desired by my customer.

The unit you saw could very well be a modification that was done by some
nameless vendor, like myself. Collins, or any of the other R390 manufacturers
likely had nothing to do with it.


Yes. Or not. Who knows?

Did you check out the R-390 website? They speculate as to the
existance of the R-9xx, a fabled variant of the R-390A that came
with an LED digital readout.

I'm verifying that such a beast exists. I . saw . it.

There is an R-9xx, an R-390 variation with an LED display in place
of the Veeder-Root counter.

How did it come about? Who built it? Donno.

I can say that it did *not* look home brew, nor did it appear to be
an engineering prototype in the sense of a "proof of concept".

It had a metal bezel that was well finished and the vendor had a
thick technical manual for it. He fanned the pages and showed the
schematic diagrams.

I didn't say that Collins made it. I said that it is documented on
a site dedicated to the R-390 and you can find it by searching for
"Collins" and "R-390" or go to http://R-390A.NET

Obviously there were not hundreds of these things made. It is also
unlikely that there was only ONE, a one-off built in a lab.

I'm *guessing* that there were several, perhaps as many as a few
dozen built, probably for NSA, but that is *guessing*. If the
customer was NSA, that would explain why few have "escaped" to the
wild.

I saw it at the Gaithersburg Hamfest in the mid-1970's. I only saw
one so that is all I can testify to.

There are other legendary receivers, some may be fables such as the
Signal/One CR-1500 which was pictured in ads but has not been seen
since.

Others, such as the Central Electronics 100R receiver designed by
Joe Batchelor, exist as production prototype models. This is
documented in the ARRL book on boatanchors.

de ah6gi/4