R-350M transceiver

This is a shortwave transceiver used for intelligence communications by special forces, GRU reconnaissance groups, and MGB airborne mobile reconnaissance units.
Development began in 1950 at the KGB research center in Kuchino, near Moscow. The first model was the R-350, codenamed "Orel," which entered into production in 1955, this was upgraded to the R-350M version in 1957. The device was manufactured with both Russian or English markings for Warsaw Pact countries.
The R-350 was the first true Soviet mass-produced spy radio.

To minimize the risk of detection and interception, short-pulse transmitters (high-speed transmitters or high speed keyers) were frequently used to keep transmissions as brief as possible. Shortening transmissions in this manner made it difficult to locate the transmitter or intercept the transmissions.
The message to be sent was first encoded into numbers and recorded onto standard 35mm photographic film - chosen because it was readily available- using a high-speed (burst) encoder; this encoded sequence was then transmitted as a standard Morse code signals using a high-speed Morse key. In this specific radio, the key was operated manually, though later versions utilized a motorized drive.
To facilitate communication, a so-called radio node system was established. These systems enabled the automatic switching of transmitters and receivers between ten preset radio frequencies, significantly reducing the duration of communication links and accelerating information transfer. Information was transmitted at a speed of 150 groups per minute.
Since the message transmitted in this way was extremely brief, it first had to be recorded in order to be processed, and then played back at a slower speed so that it could be analyzed. The information received at the radio node was captured using an R-355 unit and recorded on an R-181 magnetic disk recorder, and later on an R-180M tape recorder.