General Dynamics bought Stromberg-Carlson in 1955 so S-C was a subsidiary of GD when the SC-900 series was developed, if I understand the history correctly.

Here is an email I saved years ago:

[R-1051] SC-901

Geoff Fors geoff at wb6nvh.com 
Mon Feb 1 19:51:58 EST 2010
SC-901 and the 900 series as a whole were the prototypes designed around1961 by Stromberg Carlson.  
They were typically installed in ICBM silos and you will see them in some of the photo collections on the web.  
For example, that silo south of Tucson, Arizona, now a museum, still has them in place. 
Presumably SC- means Stromberg Carlson.
Geoff


Not to be a troublemaker, but going back up a ways on the previous page, Collins was not involved in the R-1051. It was a Stromberg Carlson design made initially for ICBM missile silos and carried SC-900 and SC-901 designations. Later, General Dynamics took over and the R-1051's are theirs, built usually by Bendix as a contractor. There are some NATO ones built by Elmer in Italy. 

The 1051 was not made to replace the R-390A, which was still in production almost 20 years after the 1051 was introduced, although the Navy stuck them in a bunch of positions at Skaggs Island where 390A's had been. The decade frequency dial-up system sure isn't a band cruiser but it's a great SSB receiver for fixed channel point-to-point use. Which is what the military used it for. They are fixed mainly by module swapping on board ship, but at the depot level, repairs to modules are somewhat of a nightmare. And they weigh almost 100 pounds.
WB6NVH 

Jim

Logic: Method used to arrive at the wrong conclusion, with confidence.  Murphy


-----Original Message-----
From: Francesco Ledda <frledda@att.net>
To: MMRCG@groups.io
Cc: mrcg@mailman.qth.net; milsurplus@mailman.qth.net
Sent: Sun, Sep 25, 2022 8:44 am
Subject: Re: [Milsurplus] [MMRCG] AN/URT-23D The 10 milliwatt monster transmitter?

Fair radio does have a couple of SC-901s. The last time I was there (last may), they appeared clean, but without their 8295s.

How did the SC-501 become the R-1051?

Best, Francesco K5URG

Sent from my iPad

On Sep 25, 2022, at 08:07, Nick K4NYW <navy.radio@gmail.com> wrote:


Correct - the AN/URT-23 series was US Navy equipment.
Ed is confusing it with the USAF's General Dynamics (Stromberg-Carlson) SC-908 amp that went with his SC-901 receiver-exciter. These SC units were evidently predecessors to the R-1051, T-827, RT-618, URT-23, family

I have just begun a page on the SC-series at

Nick England K4NYW
www.navy-radio.com


On Sun, Sep 25, 2022 at 8:50 AM Francesco Ledda <frledda@att.net> wrote:
The silo south of Tucson does not and did not have an URT-23. 


On Sep 24, 2022, at 21:40, ED SHARPE via Milsurplus <milsurplus@mailman.qth.net> wrote:

I think we have RX/exciter Nick.... a rig was used in Titan silos for hf
.have RX/exciter would love to have rest for or display at SMECC MUSEUM PROJECT in AZ...
THERE IS A WHOLE USAF USED VERSION OF THIS TYPE OF GEAR IG I AM NOT MISTAKEN IN TNE TITAN SILO SOUTH OF TUCSON AZ
HELP....
ANY IDEAS
NICK???? ( and others with ideas chip in too! Please!)

Ed#           SMECC MUSEUM 


On Sat, Sep 24, 2022 at 2:45 PM, Nick England
Look at the ability of the URT-23D and later models to transmit at only 0,01 watt up to 1KW.

I presume this is for "Limited Range Intercept (LRI)" but I don't know how this works in operation? Manually or Automagically?
===========
Link-11 - HF is used to establish a net when the range between units in the net is from 25 to 300 nm. For ranges of less than 25 nm, HF Limited Range Intercept (LRI) can be used
===========
Nick England K4NYW
www.navy-radio.com