Radio Valves

Ediswan AR

Ediswan AR bright emitter triode

Ediswan AR
Ediswan AR 1922/3
Ediswan Price List 1924
1924 prices

This is a bright emitter tungsten filament advanced version of the 'R' valve, on a nickel plated brass base. Made between November 1922 and October 1923 by Edison-Swan, this valve has a 'pip' top where it was pumped during manufacture. The official type approval BBC stamp, showing that the valve was approved and that duty had been paid, is clearly visible. This valve was still on sale in 1924, as you can see by the price list at the left. Its price of 12/6d is the equivalent of over £100 today in earnings terms. However the dull emitter, thoriated tungsten filament, ARDE and AR06 valves, with their very much reduced current demands, were already replacing it. Accumulator life between charges was extended at least tenfold by the newer valves much lower filament power which was as low as 150 mW compared to the 4 W dissipated by the 'AR' type. They could even be operated from the more portable dry cell LeClanche batteries.

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This page last modified by AJC on Friday, 26-Mar-2010