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

[wa5cab at cs.com]

TM 11 numbers were not in general assigned in numerical sequence.  There 
were blocks of numbers set aside for specific general functions (11-2xx and 
part of 11-6xx mostly for ground radio sets except that 11-200 was aircraft, 
11-8xx for receivers, 11-9xx for generators and power supplies, etc.).  First 
assignment date for numbers between 200 and 300 jump back and fourth from 
1940 to the late 50's.  The manual on the SCR-399/499-A is 11-281.  The 
manual on its successor, the AN/GRC-26 is TM 11-264.  Etc.  

MC-543, 2Z5725-543, is in the 12/45 SIG 5.  From the description (SIG 5 
doesn't often list components) it probably was the conversion kit to make an 
AN/MRC-1 from either SCR-299 or SCR-399 as it mentions an amplifier and 
high-speed TG (TG is Telegraph and probably meant CW instead of RATT).

In a message dated 1/14/2010 9:32:05 PM Central Standard Time, 
pulsarxp at embarqmail.com writes: 
> I used to operate an AN/GRC-26 while in the Army, Big Red One, Ft Riley, 
> Kansas.  Callsign:  FOGHORN.
> 
> Lee, w0vt
> Houston, Texas
> 
> 
> ----- Original Message ----- 
> From: "Duncan M. Brown" <duncanancy at earthlink.net>
> To: "greenkeys" <greenkeys at mailman.qth.net>
> Sent: Thursday, January 14, 2010 9:24 PM
> Subject: [GreenKeys] AN/MRC-2 US Army's first deployable RTTY??
> 
> 
> >
> >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.
> >

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