[GreenKeys] Help needed - Info on UGC-77 (28KSR TEMPEST)

[Nick England]

I am in the process of reverse engineering documentation for the AN/UGC-77
M28 compact KSR. And I need help! If you have one of these or the
associated electronics box, please help by answering some questions. If you
have documentation (see below) please help.

Don House is sending me a machine and I am determined to get it running as
intended. The ESA I got from Don appears to have been modified and will not
work as wired - it sure would be great if someone with another ESA could
answer some questions so I could get my reverse engineering done correctly.

The UGC-77 (and UGC-20B) uses photocells in the keyboard and distributor
(LLK4CRS) and sends these 250ua signals to an external ESA (Electronic
Service Assembly) for conversion to standard +/-6v Low-Level signaling. I
cannot find any documents specifically covering the ESA 323121 and 323130
LLK (Low Level Keyer) that are used in this machine. NOTE - it might be ESA
321231 or 323813 - the documents I have are not consistent.

Existing documents - I have 311B/RF Vol 3 and Vol 4. (NAVSHIPS
0967-173-7030 and 0967-173-7040). Both are Original Issue dated October 1969

Volume 3 includes a description of the operation of the photocell keyboard,
photocell distributor, and 323130 LLK card. BUT there are no parts listings
for the LLK4CRS keyboard/distributor, or the 323121 ESA, or the 323130 LLK
card. The 573-611-800TC Issue 1 parts listing says it covers the compact
keyboard, but it does not.

Likewise, 311B/RF Vol 4 wiring diagrams (573-600-401TC Issue 1) do not
include the LLK4CRS  keyboard/distributor, the 323121 ESA, or the 323130
LLK card. Wiring diagram package WDP 0123 might be the right one.

Of course I would love to find that later issues of 573-611-800TC and
573-600-401TC contain the parts and wiring diagram info that I need! Also
one reference says NAVSHIPS 0967-LP-170-4010 might be applicable.

Again NOTE that the ESA might be 323121 or 321231 or 323813 - It isn't
clear from the documents that I do have.

Thanks
Nick

Nick England K4NYW
www.navy-radio.com
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