Radio pick-up arm, 1932 and klystron valve, 1940.
© Science Museum / Science & Society Picture Library
This gramophone pick-up arm (top) was part of an amateur wireles transmitting and receiving station built by Mr F Briggs, and exhibited as a typical radio amateur's equipment at the Radio Exhibition, London, in 1932. The valve shown is a reflex klystron oscillator valve, type CV67, of 1940. The reflex klystron was developed as a local oscillator for radio receivers operating at centimetric wavelengths. The CV67 operated with an anode potential of 2kV, giving a minimum output of 100mW at a wavelength of 9cm.