Tells the story of how Hallicrafters developed the WWII SCR299 military shortwave radio from the pre-war HT-4 amateur ham radio transmitter.
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Tells the story of how Hallicrafters developed the WWII SCR299 military shortwave radio from the pre-war HT-4 amateur ham radio transmitter. "How radio equipment helped to win World War II."
NEW VERSION with improved video & sound: https://www.youtube.com/watch?v=dVHca7AQo_w
Reupload of a previously uploaded film, in one piece instead of multiple parts.
Public domain film from the Library of Congress Prelinger Archive, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and equalization (the resulting sound, though not perfect, is far less noisy than the original).
The SCR-299 was a U.S. Signal Corps mobile military communications unit used during World War II.
The SCR-299 replaced SCR-197 and SCR-597, and was an effort to give a long-range communication advantage to the U.S. Army and its allies. To meet these demands, a high-powered radio transmitter was required — capable of infallible voice communications over 100 miles (160 km); self-powered; sturdy enough to work in all conditions, flexible enough to cover a wide range of frequencies; and able to operate in motion or at fixed locations.
Production began in early spring 1942. Out of the various sets sent from U.S. vendors, and after considerable experimentation, Hallicrafters Standard HT-4 transmitter was chosen as the desired radio's basis. The HT-4 transmitter's new version became known as the BC-610 transmitter. The receivers finally supplied were the BC-312 and BC-342, plus the BC-614 (speech amplifier), BC-729 (tuning unit) and BC-211 (frequency meter), along with the PE-95 (power unit). All these became part of the truck-and- trailer unit called the SCR-299 — later better known as the "mobile communications unit."
SCR-299 was updated to version SCR-399, similar to the SCR-299 except it was installed in an HO-17 shelter designed to be mountable in vehicles such as 21⁄2-ton trucks and accompanied by the power unit carried in a K-52 trailer. An air transportable version, the SCR-499 was developed and became standard for the USAAF. Hallicrafters Company advertising of the period sometimes used illustrations of the shelter-mounted SCR-399 to describe the achievements of the SCR-299.
On November 8, 1942, amphibious landings of British and American forces for Operation TORCH presented the Signal Corps and the SCR-299 with its first major test of the war. Companies of the 829th Signal Service Battalion assigned to each task force attempted to set up the administrative communications net with SCR-299 truck and trailer radio sets immediately upon landing. The plan was to connect the widely separated landing areas and to communicate with Gibraltar. Unfortunately, the weighty sets had been stowed deep in the holds of the convoy ships and only one could be unloaded in time for use during the initial assault. Luckily, British communications ships filled the gap until the SCR-299's could be landed. Once onshore, the sets provided the chief means of long-distance signals until permanent Army Command and Administrative Network stations could be installed. General Dwight Eisenhower credited the SCR-299 in his successful reorganization of the American forces and final defeat of the Nazis at Kasserine Pass.
Though the original Signal Corps requirements were for communication points up to 100 miles (160 km), under favorable conditions these transmitters made and maintained contact over 2,300 miles (3,700 km) of land and sea...
The SCR-299/399 received fairly heavy use by war correspondents and members of the press corps...
The SCR-299 was a complete mobile HF station on frequencies from 2 to 8 MHz (and 1--18 MHz using conversion kits) with transmitter output of 350 watts. The entire unit came in a K-51 truck except Power Unit PE-95 which was in a K-52 trailer. Power could either be supplied by the Power Unit and a 12 volt storage battery, or 115 volt 60 cycle AC commercial power and two spare 6 volt storage batteries. The power requirement was 2000 watts, plus 1500 watts for heater and lights.
The system could be remotely controlled up to a distance of one mile (1.6 km) using two EE-8 field telephones and W-110-B Wire kit. Remote equipment was provided for remotely keying or voice modulating the transmitter, remotely listening to the receiver, and for communicating with the operator of the station.
Frequency Conversion Kit MC-503 gave coverage down to 1 MHz. Frequency Conversion Kit MC-516 gave coverage to 12 MHz and Frequency Conversion Kit MC-517 gave coverage to 18 MHz...