Bendix Radio enjoyed a very close association with the Navy as early as the mid-1930s. Some of their equipment, like the DU series loop preselector for the RU receiver and their MT-11 telegraph key, was even redesignated with Navy numbers and used throughout the war. By the time the war came, the light gray wrinkle finished commercial aircraft gear was being specified as standard equipment for several Navy aircraft, without the usual re-nomenclaturing ceremony. The Signal Corps eventually adopted the MN-26 DF receiver for many of the USAAF aircraft as well, and of course the SCR-269 and its antecedents, and the AN/ARN-7 culmination of that line were also Bendix products.

The example above is the TA-12B model, which differs from the more common -C model only by the frequency range. It was primarily used for shorter range HF comms in light aircraft. It is shown with its MT-51 control box, MT-31 tuning meter, MS-14 junction box, and MT-66 dummy load (partially seen at top right. (The radio compass is just perched there for scale.) Unseen behind the transmitter is its dynamotor/modulator, the MP-28.

The mating receiver for this transmitter is normally a Bendix RA-10, but that is detailed over on the Navigation page, as it was also used as a DF receiver.

Probably because of commercial aircraft lineage, a late 1930s Bendix transmitter was used in some Navy transport aircraft as another high power alternative to the Navy GO series, (see Navy Day) despite the continued production of the Westinghouse GO (-9 by then). The TA-2J above was a significant improvement over the GO-* series in that it was capable of eight remotely selected crystal controlled channels and was significantly smaller and lighter, despite using the same 803 PA. Channel selection was accomplished with a large motor driven rotating drum, containing all the tuning elements except the crystals. No tank capacitor was used, the designers having proceeded to the logical conclusion that aircraft antennas provide enough capacitance to serve that function except for low frequency work. The schematic is shown at TA-2J Schematic.

As you can see, there is really no capability for local control of the set. An emergency crank handle for changing frequencies is to the right of the doghouse "autotune" motor box, but it isn't what you would call user friendly - what seems like a thousand turns gets you to the next channel. Unlike the GO series, which was CW only, this transmitter had a built-in modulator. The antenna output terminal is installed in a phenolic plate in the hole at upper left. Below are some additional views of the set interior.

The receiver listed as the mate to the TA-2J in the Navy aircraft compliment tables was the RA-1B above. Possibly the only continuous general coverage receiver Bendix made until well after the war, it was compact and very popular with commercial airlines. (Their other wartime receivers all had spotty band coverage for specific purposes.) I noticed one at the Dayton hamfest a few years ago with a United Airlines tag on it. This particular unit shows the matching dynamotor to its right. Like a number of the local control Bendix sets designed in the 1930's (the original manual is dated 1938), a toggle switch in the "down" position was considered "on". This rather interesting convention reflected the British human factors influence on the design concept. The strange structure to the right of the tuning dial is a dial light. The schematic and other information is shown at RA-1B Manual Excerpts