...and, of course, don't forget the redoubtable AN/GRC-106.  All these
historically important radios are descendants of the original SC-900
family.  The SC-900 series was indeed well ahead of its time,
particularly its frequency synthesizer, and GDE got a lot of
evolutionary mileage out of that baseline design.  The GRC-106A was
still being produced at Cincinnati Electronics in the early 1980s.

The core group of engineers that founded RF Communications, Elmer
Schwittek, Bill Stolze, and Roger Bettin (plus lawyer Herb VandenBrul)
all  worked at Stromberg-Carlson/GDE.  Both companies were in Rochester,
NY.  In the ensuing years, a number of other engineers came over from
GDE to RF Communications (later acquired by Harris Corp).  The result
was that some of the same people who worked on the SC designs worked on
the design of RF Comm products such as the highly advanced RF-110 power
amp series, and the evolution is plain to see.  I worked for Harris
Corporation (in Florida) for 20 years, but worked closely with and knew
many engineers at the RF Comm division in Rochester, and spent a lot of
time up there.  There were still a few old S-C/GDE hands there and in
Florida at the time...

73,

John K9WT



On 9/26/2022 10:16 AM, W2HX wrote:
>> It would be interesting to know how the transition from the SC product line to the RT-618/R-1051/URT-23 happened.
> And don’t forget the T-827
>
> 73 Eugene W2HX
> Subscribe to my Youtube Channel: https://www.youtube.com/c/w2hx-channel/videos
>
>
>
> -----Original Message-----
> From: mrcg-bounces@mailman.qth.net <mrcg-bounces@mailman.qth.net> On Behalf Of Francesco Ledda
> Sent: Monday, September 26, 2022 10:13 AM
> To: Jim Whartenby <old_radio@aol.com>
> Cc: mrcg@mailman.qth.net; milsurplus@mailman.qth.net
> Subject: Re: [MRCG] [Milsurplus] Navy WRC-1 & URC-35 family history - Stromberg-Carlson SC-900A
>
> Jim,
>
> The SC-900 was surely ahead of its times. Potentially, it was vastly superior to the KWT-6. I am totally in the dark about the possible youth problems that the SC-900 may have suffered from.
>
> The SC-908 amp was not very successful, and its follow up (URT-23) was totally different and therefore not an evolution of the SC-908. It would be interesting to know how the transition from the SC product line to the RT-618/R-1051/URT-23 happened.
>
> Regarding the URC-32/KWT-6, as you well know, it is not auto tuned, and it is a simplified version of the ARC-58. There was another version of the URC-32 that kept the auto tuning capabilities of the ARC-58.
>
> Best, Francesco K5URG
>
> Sent from my iPad
>
>> On Sep 25, 2022, at 22:24, Jim Whartenby via Milsurplus <milsurplus@mailman.qth.net> wrote:
>> 
>> If the SC-900 development started in the Fall of 1958, that answers the question of which of the three systems came first.
>>
>> Another thing is that the SC-900 is contemporary with the KWT-6.  The original ground station developed during Birdcall used a receiver - exciter similar to the 310F-1 as shown in a photo in the Fall, 1958 Collins Signal, Volume 7 # 2.  This is essentially an ARC-58 receiver - exciter, for automatic tuning, repackaged for rack mounting with a 60 to 400 cycle motor - generator.
>>
>> Not exactly sure when the KWT-6 made it's debut but it certainly wasn't ready for Birdcall in the mid to late 1950's.
>> Regards,
>> Jim
>>
>> Logic: Method used to arrive at the wrong conclusion, with confidence.
>> Murphy
>>
>>
>> -----Original Message-----
>> From: Nick England <navy.radio@gmail.com>
>> To: Jim Whartenby <old_radio@aol.com>
>> Cc: mrcg@mailman.qth.net <mrcg@mailman.qth.net>;
>> milsurplus@mailman.qth.net <milsurplus@mailman.qth.net>
>> Sent: Sun, Sep 25, 2022 4:48 pm
>> Subject: Navy WRC-1 & URC-35 family history - Stromberg-Carlson
>> SC-900A
>>
>> OK - The internet tar-baby got me today but I believe I now have a
>> solid history - See https://www.navy-radio.com/xmtrs/sc-radio.htm
>>
>> I have added photos and references to the SC-901X transceiver, 907,
>> 908A, and 910A amplifiers, 910R receiver, 910E exciter, and 905C
>> antenna coupler. These were sold commercially (beginning in 1961 I
>> believe) and to the USAF as a result of a 1959 USN R&D Contract. The
>> Navy's R-1051, T-827, RT-618, URC-35, URT-24, and WRC-1 resulted from
>> this contract
>>
>> Aha! - I found a patent case showing that in June 1959 the Navy contracted with Stromberg-Carlson (General Dynamics) "to design and furnish experimental, mock-up, and developmental models of a single sideband radio set and a single sideband portable transceiver." (NObsr-77628, dated 16 June 1959 for AN/WRC-1 and AN/URC-35). The Navy had rights to patents developed during the contract, but General Dynamics claimed some of the inventions "were conceived and reduced to practice during plaintiff's own, independent project to develop a single sideband transceiver, called the SC900A, prior to the award of contract NObsr-77628".
>> That led me to the SC900A development background.
>> https://www.navy-radio.com/xmtrs/sc/SC900A-Board_of_Contract_Appeals_D
>> ecisions.pdf Evidently they had a working radio before the Navy
>> contract was signed.
>>
>> Trivia - the original Navy contract referred to the AN/PRC-45 portable transceiver and AN/URC-35 fixed transceiver. The names were later changed to AN/URC-35 portable transceiver and AN/WRC-1 fixed transceiver.
>> [The URC-35 was called portable - HA!]
>>
>> And finally I found this -
>> April 1959 Stromberg-Carlson Advertisement -
>> - A new approach to Single-Sideband radio by Stromberg-Carlson...... greater power output, less power input with a smaller volume.
>> - The SC-900A digit-tuned Single-Sideband transceiver marks a significant advance in the state of the art.
>> - The SC-900A is designed for both vehicular and fixed point-to-point communications adaptable to rack mounting and back-pack meets full military requirements.
>> - Provides 28,000 stabilized channels from 2 to 30 megacycles, with a transmitted peak envelope power output of 100 watts.
>> - Receive input power : 50 watts.
>> - Average transmit input power for voice: 150 watts.
>> - Available soon.
>>
>> Any additional info, photos, etc. would be greatly appreciated Nick
>> England K4NYW www.navy-radio.com
>>
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