This is a type 417A klystron with a 'WL' prefix. The 'WL' prefix indicates the manufacturer. Small klystrons of this class usually generated around 300 mW of microwave output and were widely used as local oscillators in radar receivers.

They were normally tunable over a modest range and were adjusted to be exactly in tune with the (much more powerful) pulse transmitting valve (usually a cavity magnetron). The magnetron generated an RF output only briefly, when pulsed, but the klystron provided a continuous low-level RF signal which could be used to 'beat' (mix) with the faint echo signals in order to reveal small frequency differences of Doppler shifted echoes from moving aircraft.

The type 417A was fairly early WW2 but this specimen looks to have been made post-war.

This klystron has an International Octal base and co-axial take off ports. The three screws and pair of sprung flanges suggest a means of tuning.

This device was used in type SCR287 track and follow radar. Its function was a local oscillator within the receiver.

The wide metal tube envelope is 35 mm in diameter and, excluding the IO base pins, is 110 mm tall.

This exhibit was last updated on 07 August 2006