[GreenKeys] AN/MRC-2 US Army's first deployable RTTY??

[Duncan M. Brown]

We were having a discussion on another list about the US Army's first
tactical/deployable radio teletype system.  I believe it was the AN/MRC-2
(a derivative of the WWII SCR-399).  I have scanned a few pages of the
manual that describes it and it can be seen at
http://www.commcenter-2.net/media/cpg/displayimage.php?album=5&pos=3
(Due to the binding and the fact that it is 350 pages, I didn't scan the
whole thing!) 

The AN/MRC-2's earliest TM 11-624 manual date is Nov 1947. The AN/MGC-2 is
basically an SCR-399 with the addition of a 2KW amplifier added on to the
BC-610, diversity radio teletype converters and Teletype Corp. model 14 and
15 teletypewriters in three shelters.  

A similar, but smaller unit is the AN/GRC-26.  It is a MRC-2 without the 2
KW amplifier and in a single shelter.  The earliest manual date I have
found for the AN/GRC-26 is Nov 1950.  However the GRC-26's manual number,
TM 11-264, precedes the MRC-2 by quite a bit, so maybe the GRC-26 had been
in the planning stages for a while.  
 
On the Ft Gordon web site, there is a page on the SCR series radios
http://www.gordon.army.mil/ocos/museum/scrcomponents/scrPart2.asp and it
states that the SCR-399 "Developed into the AN/GRC-26 & AN/MRC-2."  It also
says that there was a modification "MC-543 provides added equipment for
two-kw RITTY operation."  So perhaps the AN/MGC-2 equipment combination
existed prior to 1947 as a modified SCR-399.  
 
During WWII, the 3104th Signal Service Battalion operated radio teletype. 
They arrived in France on 22 July 1944 and initially set up RTTY circuits
using commercial equipment.  They also had SCR-399 radios and they may have
modified them later for RTTY.  (
http://www.fgrubbs.com/3104/3104grubbshistory.htm )

If you have never seen "Voice of Victory", the story of the SCR-299/399 and
the militarization of the Hallicrafters HT-4 transmitter into the BC-610
transmitter, it is available on Youtube at 
http://www.youtube.com/watch?v=Jps0_2adUvo

 
Just a little history for your enjoyment.
 
have fun,
 
Dunca