The Bush AC31 is a British valve radio introduced in 1952. It is a classic example of early 1950s domestic radio design, with a wooden cabinet, three wavebands and a four-valve superheterodyne circuit. The AC31 was designed when radio was still a major source of domestic entertainment in Britain, before television had become universal.
It has several appealing features:
- Three wavebands: The inclusion of short wave meant listeners could receive overseas broadcasters as well as domestic services.
- Traditional valve sound: Its EL41 output valve drives a relatively large loudspeaker, giving it the warm, rounded sound associated with vintage valve receivers.
- Good construction: Bush radios had a reputation for solid engineering. Contemporary collectors have described the AC31 as a good performer, particularly considering its straightforward four-valve design.
- Mains transformer: Unlike its related DAC31, the AC31 was designed specifically for AC mains operation, using a transformer and an EZ41 rectifier valve.
Valves
- ECH42 – frequency changer, combining mixer and local oscillator
- EBF80 – intermediate-frequency amplification, detection and automatic gain control
- EL41 – audio output amplifier driving the loudspeaker
- EZ41 – full-wave mains rectifier supplying the high-voltage circuits
The service manual for this radio is available in the Members’ Area.
