kh wrote:

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.

Yes, I checked out the site. They said that there were rumours that
a R9xxx, with a LED display existed. No pictures, though. Not real
satisfying.

I know that I've seen one too. I seem to recall an EAA tag on 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".

Everything I mod looks a professional as the original manufacturer.
That is part of the job. It is surprisingly easy to do. I now have
a full machine shop at my disposal, but in the past, I have done
professional looking instruments using hand tools. I have engraved
panels, and other foolish things, to make a good looking product.


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.

That's easy stuff too. If it was a modification of an existing unit,
most of the original manual would apply. Pen a few words about the
modification, and make some schematics using Orcad, and you have a
professional looking manual. Even the etched aluminum ID tags
are easily made.


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.

On this I disagree. I think the one I saw was likely one of maybe
10 units. It was very much like jobs I have done in the past.


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.

Surplus is surplus. Most everything the government buys ends up there
sooner or later in some form. NSA surplusses lots of stuff. Even
interesting things. Usually their gear has had the name plates and
serial numbers removed. (causes interesting problems here in the
peoples republic of MD where it is illegal to possess anything that
has had its serial number altered, or removed.)


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

As I have said, I have seen it too. Probably at the same G'burg fest
as you saw it in... I am a MD boy. I know I could do one just as well
as they did... if someone were willing to pay my freight.

-Chuck