[Premium-Rx] WTB: Watkins Johnson 8940 Tempest Rx System

[W2HX]

Fascinating. I would love to see a picture of this and know its basic details like frequency range.  My other hobby is ruining some PDP--11s so i wonder if this would be a cool system to acquire to combine two interests for me

Eugene

________________________________________
From: Watkins-johnson at terryo.org <Watkins-johnson at terryo.org>
Sent: Friday, May 25, 2018 1:54 AM
To: W2HX
Cc: Jeff Kruth; ka2ivy at verizon.net; Premium-Rx at mailman.qth.net
Subject: Re: [Premium-Rx] WTB: Watkins Johnson  8940 Tempest Rx System

The 8940 is an interesting part of WJ history.  The first version was
produced under extreme duress.  Based on interviews I've done it was
pretty ineffectual, but satisfied the urgent contract under which it was
developed.

The A version, which was a major redesign, worked better.  It was designed
to work with a PDP-11 but they weren't a smooth coupling.  A test engineer
for GTE who used one extensively on crypto machines told me he had to
reboot the PDP often because they would stop working together.  I had one
of these with all the manuals and basically gave it away.  A lot of space
and too much work for too little return.

The B version worked out many of the kinks and expanded the capabilities.
It worked well and was apparently well liked.  It still leaves a lot to be
desired as a standalone receiver because it was also designed to be
computer controlled.

The TSU and some modules of the B version were redeveloped into another
receiver system as part of a larger contract with Iran but was never
delivered.  A multipoint monitoring system was also developed for Germany
that was delivered.

The 8940 was third wide spectrum analysis system that WJ developed.  The
first two systems were even more cumbersome in size and operation.

I have a lot of information on all of these systems and iterations. My
websites are way behind my research because the digging is going so well
that posting is way down the priority list.

Terry O'
http://Watkins-Johnson.terryo.org
http://BlackRadios.terryo.org


> Sounds fascinating. Where can one findany photos of such a system? Google
> didn't help.
>
> Sent from Nine<http://www.9folders.com/>
> ________________________________
> From: Jeff Kruth via Premium-Rx <premium-rx at mailman.qth.net>
> Sent: Wednesday, May 23, 2018 4:35 AM
> To: ka2ivy at verizon.net; Premium-Rx at mailman.qth.net
> Subject: Re: [Premium-Rx] WTB: Watkins Johnson 8940 Tempest Rx System
>
> Hi Bruce!
>
>
> I have two of them and would part with one.  They cost me a bit back in
> the day. Complete system, desk and all, cables etc.  I may even have some
> documents for loan to copy. We can discuss the price. Shipping would be by
> freight or you could pick it up.  These were functional units when I
> bought them, and have been in storage (in my lab) ever since. Never got
> around to using them, so they have sat in the corner. Not many were made,
> and at one point WJ had a sale for one of mine to Denmark, as WJ did not
> want to build a one-off. It was from this that I learned they were $300K.
> Did not come through. This was back just at the time the Clinton Admin
> killed the Tempest requirement.
> They are really quite the thing!
>
> 73
> Jeff Kruth
> WA3ZKR
>
> In a message dated 5/22/2018 8:29:15 PM Eastern Standard Time,
> ka2ivy at verizon.net writes:
>
>
> I happened upon a brochure for the Watkins-Johnson WJ-8940 receiver in
>
> the desk console. Has anyone seen one of these, and even more important,
> does anyone have a project one they are willing to part with? It looks
> like a neat rig, restoring one would be quite a project but that's the
> kind of puzzle and challenge I would like.
>
>  Bruce Gentry, KA2IVY
>
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