Marconni Transmitters

In the early 1950s, a prototype Marconi HS 51 transmitter was installed in the ‘A’ Building Machine Room to allow the design to be finalised before another 28 transmitters were installed in the ‘B’ Building. This Marconi HS 51 transmitter later became operational, as number A30. It had solid state EHT rectifiers installed unlike all of the, almost identical, ‘B’ Building transmitters, which used AR63 Mercury arc rectifiers.