Mufax chart recorder type D-665-C (top), and Mufax picture receiver D-611-Uf, complete with supply unit no 442574 (bottom), manufactured by Muirhead and Co Ltd. The Mufax chart recorder is used on ships for receiving meterological maps and wire photos by radio. In this machine, audio signals are converted to current pulses which pas through a helix, acros the paper to the writing edge. Each time a current is applied to the helix the paper is marked, so that when when scanning is complete, a clear image is produced.
© Science Museum / Science & Society Picture Library