Mullard thermionic valve in box

1945 in England

Mullard thermionic valve in box
Science Museum Group
© The Board of Trustees of the Science Musuem

Mullard thermionic valve rectifier in box

AZ31 from National Valve Museum:

The AZ31 directly heated full wave rectifier and is fitted with an IO base unlike the earlier AZ1 that had the continental Ct8 base. The AZ31 has identical electrical characteristics to the AZ1. It has a 4 Volt filament rated at 1.1 Amp. The maximum anode RMS voltage is 500 Volts. At this anode Voltage the DC current could be up to 60 mA. At 400 Volts on the anode the output could rise to 75 mA and with 300 Volts on the anodes the output current could be 100 mA. The maximum reservoir capacitor had to be no more than 60 µF.


Radio Communication
Object Number:
cardboard, glass, metal (unknown) and plastic (unidentified)
thermionic valve

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