Re. post #65, I am 430 miles north of Kansasa City, MO. Dallas, TX is about 500 miles south. The Linda Hall library is too far away just to drop into.
Louis Meulstree provides brief information on the army radio serts in his book "Wireless for the Warrior, Compendium 2" (Spark to Larkspur: Special Sets, Receivers and Larkspur). These sets are described as:
R211, triple diversity SSB receiver for the army wireless chain. Also known as the CRD/150/20A with 3 CRD/150/4 receivers, and a SSB rack type SSR2.
R217, also known as Marconi HR11. Adopted by the army for use in COMCAN. Shown as doing FSK, MCW and CW only.
R230, also known as Marconi HR27. Developed as a companion to the D11 transmitter.
R234, also known as Marconi HR28. Developed as a companion to the D11 and D13 transmitters.
R235, also known as Marconi HR23. Triple diversity receiver for COMCAN
In addition, under the discussion about the Station Radio E11, also known as the ST&C DS22, the radio was originally envisaged for use with the R217 for FSK (see above) or R228 (Marconi HR13) for SSB and ISB. The book suggests that the requirement for the R228 was abandoned and existing receivers used instead.
It is very good to see the Marconi information online. Receivers are listed at:
http://marconiincommunications.pbwor...20-%20Products
One army point-to-point receiver which was not made by Marconi was the R212. This was a triple diversity receiver built by ST&C in their "International" class. It was introduced in 1948/49.
Another indication of point-to-point practice in the USA in the 1950's is given in:
H.E. Goldstine, G.R. Hanselland R.E. Shock, "SSB Receiving and Transmitting Equipment for Point-to-Point Service on HF Radio Circuits", Proc. Institute Radio Engineers, Vol. 44 No. 12, Dec 1956, pp 1789-1794. It describes the SSB-R3 receiver and the SSB-T3 transmitter. This issue of the Proc. IRE was the "Single Sideband Issue"
The bibliography on Single-Sidebands is not widely known. It is also a very rare book - I have only found listings for copies in 5 or 6 libraries in the USA and Canada. If one is interested in SSB it is invaluable. It was published in the 1956, ie too late to be referenced in any of the papers in the Proc IRE Single Sideband issue (see above). This is the first volume which covers non-classified history. The second volume covered classified information. They were prepared by Mildred Benton, who was at one time the head librarian at the US Naval Research Laboratory. As it was prepared by a US Govt. employee in the course of their duties, it is not subject to copyright in the USA. This is why the full copy is available at Google.
73 John