BVWS Bulletin Volume 5, Number 4 (March 1981)
Front cover: Edison Swan 'One-Der' receiver employing an unusual double triode valve.
|50||The Power Valve 1920-1940 Part 1.
|Early valves designed to drive loudspeakers; Mullard PA1 and PA2, Ediswan PV1 and PV2, and Marconi-Osram LS1, LS2 and LS3|
|53||The Edison Swan 'One Der'.
|An unusual receiver using a single ES220 double-triode valve.|
|56||Loudspeakers Part 5.
|The moving cold loudspeaker.|
|59||Re-Inventing The Wheel.
|Carborundum and its rectification effect / use as a detector.|
|62||The Compact Variable Disc Condenser.
Anthony Constable & Roger Snelling
|The disc condenser developed by C.S.Franklin and patented in 1907.|