[BC] Re: What are these?

[Mark Humphrey]

The top unit is one of the Communications Electronics, Inc. 901 Series
receivers.  CEI merged with Watkins-Johnson, hence the similarity in
appearance.

As Bob and Bruce have said, these are VHF "surveillance receivers"
which were primarily used by government agencies.  They tune the
entire 30-300 MHz range in two segments (selected by the knob in the
lower center of the panel) using Mallory "Inductuners" for improved
stability.   The two front ends and IF strip are based on Nuvistors,
with a few transistors used in the squelch and metering circuits, AGC,
etc.   Beautiful mil-spec quality that originally sold for close to
$3000 in the '60s.

I have a CEI 975, which is very similar to the 901-1, except that it
has three IF bandwidths: 60k, 300k, and 3MHz (for video) and the lower
tuner covers 30-90 MHz.  It was found in a pile of boxes at the
Gaithersburg hamfest when the seller was packing up his truck on
Sunday afternoon.  I offered $25 not knowing what shape it was in, and
it was certainly worth it.

Here's a very informative website on the 901 series and other CEI and
WJ receivers:

http://watkins-johnson.terryo.org/CEI-Receivers/901-1.htm

Mark


On 10/19/07, Bruce Doerle <bdoerle at mail.ucf.edu> wrote:
> Bob,
>
> I know you must have seen many of these converters; they were prevalent in 60s and 70s in the DC area.  They look like the same ones the FCC use to use as well as  a boat load of other Federal agencies.  I thought they were made by CEI or WJ since they have the black front; that one looks closer to later Watkins Johnson box.  They were fine boxes.
>
> Bruce
>
> >>> r j carpenter <rcarpen1 at verizon.net> 10/19/2007 2:14:57 PM >>>
> Top item is a VHF radio or converter by NEMS/CLARK or one of its many
> spinoffs in the Silver Spring / Rockville, MD, area..
>
>