GEC BC 3235
All Electric 3
This early mains receiver is the Gecophone All Electric Compact Three, BC3235. It dates from 1931. A model was shown at the V&A 1977 "Wireless Show". It is a straight TRF circuit with a rather fine moving iron loudspeaker. Separate grid and anode tuning is employed.
The valve line-up is:
MS4 HF amplifier
MH4 Leaky grid detector (with reaction)
U10 Mains rectifier
Volume control is by aerial trimmer, and capacitative reaction is used. The HF amplifier has an RF choke in the anode circuit, and is capacity coupled to the detector. There is an intervalve transformer which couples the detector to the output pentode. This has an LF choke in the anode circuit, and is connected to the loudspeaker through a capacitor. The output valve is directly heated and has its own centre-tapped filament winding on the mains transformer. The HT is smoothed by an LF choke, and a resistor in the HT
negative return provides bias for the PT4.
The construction of the set is very solid and heavy.
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