British MCR-1 (miniature communications receiver) from World War II. This modular valve based secret receiver was designed by Captain John Brown in 1943 and built by Philco. It was intended for the SOE and Special Forces and was later adopted by the Army. The receiver's internal designation was Type 36/1, but it is commonly known as the Midget Communications Receiver MCR-1. The MCR-1 consisted of a rectangular receiver with four plug-in coil packs that could be attached to one end, a separate power supply the size of the receiver, and various accessories. The units were distributed in watertight sealed steel cookie tins, which is why they were nicknamed "Biscuit Tin Receivers". Many were dropped over occupied Europe to receive the often encrypted messages, and the MCR-1 became a very popular receiver with resistance groups in various countries. The receiver was also used as part of complete radio stations such as the Type 46/1 (Jedburgh Set) and the Type 48/1 (Nicholls Set). Production of the receiver began in late 1943, and more than 30,000 were manufactured by the end of the war. After the war, the MCR-1 became a sought-after collector's item, as only a modest number survived. Some MCR-1s were shipped with a 14-page accompanying booklet that included operating instructions, antenna recommendations, examples of covert operations, and complete schematics.
MCR-1 Manual
