Summary

Expanse B. Triode for detecting radio signals.

Made by the Amalgamated Wireless (Australasia) Ltd, Sydney and including an innovation patented by David Wyles, wireless engineer, Sydney (Australian patent 17569 - 219, 1920) and an Amalgamated Wireless assigneee.

The patent covered the extension of the connecting wires through the glass tube in such a manner that they would not be broken so readily, and if broken, be more readily repaired.

The ebonite caps at the ends of the valve are an improvement on the first model (ST 021713), actually only called EXPANSE. Otherwise same as the De Forest "Audion" (ST 15477). Same as ST 018562 and ST 018563.

Physical Description

One end of the tube is broken off; the ebonite cap is missing.

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