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 Post subject: NEMS-Clarke 1037F and REU-300C
PostPosted: Feb Wed 14, 2018 6:33 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
I found these here locally today - $47 for the pair. Both are working, although the REU-300C is missing its 417A tube, so the lower range is not working.
I'm looking for a little more info on the 1037. I found the "brochure" online, which has a block diagram that is too fuzzy to read... A better block diagram, or perhaps even a schematic?
It came with a 55-260 MC tuner, and the 500KC FS discriminator. Is there a different thing that can plug into the the FSD slot?
I understand that the upper plug-in slot is for a spectrum display - will anything else plug in there?

Thanks!
Pete


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Feb Wed 14, 2018 4:02 pm 
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Joined: Jan Mon 28, 2013 9:35 pm
Posts: 1484
Location: Santa Rosa, CA
I've got a 1037 as well as some other Nems-Clarke equipment
and would also be interested in any schematics or manuals.
They made high quality equipment but its specialized
with very wide IF bandwidths for telemetry or video. Not
very useful.
Steve

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'cell phones and the internet are tools, not a lifestyle'


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Feb Wed 14, 2018 5:11 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
Fortunately for me, "practical" is not a consideration - Ha! :-)
Last night I dug up a 5842 (417A), so that part of the REU is now working also.
My interest in this stuff is the equipment I document here:
http://militaryradio.com/spyradio/
I also have a NEMS-Clarke 1400, seen here:
http://militaryradio.com/spyradio/intercept.html (I need to post a better picture...)
CIA used these radios routinely, especially in the R&D lab. Have declassified docs that mention 1302A, 1306, 2801, 1702A, and 1501.
NEMS-Clarke built some gear specifically for CIA - probably not so much complete radios, but rather certain accessories and sub-assemblies, I think.

Pete


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Feb Thu 15, 2018 10:42 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
Here are some specific questions, in case anyone knows (or can make a good guess):

- What does the "Manual Gain" knob do? It is concentric with the Video Gain knob. I can't see that it affects anything.
- What is the "TSC" connector on the back?
- What is the "Playback Input" connector for? I suppose it's a 30 MC video input, such that a recorded signal can be played back through the receiver's IF, filter, and discriminator stages? True?
- Is the upper plug-in slot only for a spectrum display, or can something else go there?
- What other types of discriminators can plug in to the spot where the FSD is?

Meanwhile, I did something foolish today: While the unit was powered up, I removed the back-panel cover over the two power transistors to see what types they were. The cover shorted to the case of one of the transistors - there was a spark and a bad smell.
Both AC fuses blew. After checking to see what I had broken, I found that one of three bridge rectifiers is the PS module was shorted (the one for the -12.5V supply). I replaced it, and checked the nearby transistors - all good. Everything's working again. The module was easy to work on - transistors are socketed, and there is just enough room to work in, and easy access to both sides of the PCB. Nice quality stuff!

Thanks,
Pete


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Feb Thu 15, 2018 11:41 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
Figured out the "Manual Gain" knob - it only works when the AGC knob is set to "MANual".
Doh.

Pete


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Feb Fri 16, 2018 12:32 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
...And I see that there are several FSD-series plug-ins with different BWs. So that answers another question.


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Apr Sun 08, 2018 6:37 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
Was trying to draw my own block diagram for the 1037F receiver, by looking at how the modules are connected.

One of the internal modules is a "TSC" - any ideas what that is?

The TSC is fairly simple: a coaxial input and output, 4 transistors, 1 diode, 2 caps, no inductors, 1 trim pot, power, ground, and one other unshielded wire. One of the coaxial connections goes to the 2nd IF (can't tell if it's input or output).

FYI, the list of main modules in the 1037F are:
Tuner (plug-in)
1st IF
2nd IF
Limiter
Discriminator (plug-in)
TSC
Video amp
Metering amp
Power supply

Thanks,
Pete


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Apr Wed 25, 2018 4:04 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
For those that might be interested:
The "TSC" module appears to be this:
The input to the TSC module comes from the 2nd IF module.
The output from the TSC module goes to a BNC connector on the back panel.
The output signal is "digital": 0 or 6.7V. The signal is High when the received signal strength is above about 50uV (as indicated on the front-panel meter).
So, perhaps it is used to control something like a tape recorder or an alarm, when a strong signal is received.
The TSC module has a trim-pot, which perhaps adjusts the threshold (I didn't try changing it).

Pete


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Apr Thu 26, 2018 10:18 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
On this page, just above the picture, I added a link to my hand-drawn block diagram, plus notes about what the rear-panel connectors do:
http://militaryradio.com/spyradio/intercept.html

Pete


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Apr Sat 28, 2018 5:28 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 3377
Location: Seattle WA US
Possibly TSC = Tape Shuttle Controller ?? Tape shuttle controllers were often used with time code readers to repetitively read a segment of tape for analysis. This TSC module might be used with a shuttle controller to link tape motion to presence of a signal.

-Chuck


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 Post subject: Re: NEMS-Clarke 1037F and REU-300C
PostPosted: Apr Mon 30, 2018 8:33 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 122
Location: Colorado Springs, CO
Sounds reasonable - thanks Chuck!

Pete


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