Miniature Communication Receiver (MCR) Clandestine receiver with instruction booklet, four coils and mains power supply unit (PSU), c. 1944, made by Philco, developed in 1943 by Capt. John Brown of the Special Operations Executive (SOE) and Special Forces (SF) and distributed in water-tight sealed biscuit tins. Clandestine Miniature Communication Receiver, c.1944 circa 1944