[GreenKeys] USN shipboard TTY switch - red and green

[Nick England]

For the archives and on the faint chance that I'm not the only one
interested in this subject -
http://www.navy-radio.com/rtty-patch.htm#sa734

On board USN ships there are SA-734/SG switches with keylocks, allowing you
to connect a TTY to an UNCLASSIFIED (black) or CLASSIFIED (red) TTY patch
panel. The UNCLASSIFIED black patch panel is connected to radio
transmitters and is for text that can be sent in the clear or has already
been encrypted. The CLASSIFIED red patch panel is for sensitive text that
must be encrypted before transmission.

The SA-734 switch is also connected to an ID-866/SG Indicator Lamp located
near the TTY machine that is connected to the switch. In an odd decision,
the Indicator Lamp shows RED for CAUTION-UNCLASSIFIED and GREEN (or CLEAR)
for CLASSIFED connections of the TTY. The thinking must be that the RED lap
will warn you that you are connected to an UNCLASSIFIED circuit and that
you had better not accidentally send any Top Secret info.

I had puzzled over whether this is really correct, and have seen switches
and indicators wired BOTH WAYS aboard museum ships. But I have recently
obtained both the official specification and the official manual and indeed
the RED LIGHT means you are connected to the BLACK SWITCHBOARD. Honest.
http://www.navy-radio.com/rtty-patch.htm#sa734

p.s. If anyone has a spare KW-26 or KW-37 system that I can add to my
basement TTY setup please let me know :-)

Nick England K4NYW
www.navy-radio.com
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