Summary

This valve contains almost all of the circuit of a 3 valve radio. There are three triodes, 4 resistors and two capacitors. The circuit is a biased detector followed by two audio stages. It is considered to be the world's first integrated circuit.
They only required the addition of a tuned circuit, batteries and headphones or loudspeaker to produce a complete radio for local station reception.
Placing all of the valves in one bulb minimised the tax payable on the radio because in Germany at that time radios were taxed at a rate based on the number of valves used.
Used in the Loewe OE333 Ortsempfänger. (Ortsempfänger means local receiver)
4 V directly heated cathodes.
Manufacturer: Loewe Radio, Berlin, Germany.

Physical Description

Cylindrical bulb on an unique base, mounted on wooden display block.

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