Transmitter unit from the SSTR-1, also known as TR-1, a modular valve-based clandestine transmitter/receiver set developed in 1942 for the US Office of Strategic Services (OSS)—the forerunner of the CIA. During World War II, the SSTR-1 spy radio set was used extensively by OSS agents operating on occupied (European) territory, by resistance organizations throughout Europe, and in the China-Burma-India theatre. The transmitter is in its original metal case, measuring 9.5″ x 4″ x 3.75″.
