BVWS Bulletin Volume 5, Number 4 (March 1981)
Front cover: Edison Swan 'One-Der' receiver employing an unusual double triode valve.
| Page | Title | Summary/Notes |
|---|---|---|
| 50 | The Power Valve 1920-1940 Part 1. Philip Beckley | 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'. Anthony Constable | An unusual receiver using a single ES220 double-triode valve. |
| 56 | Loudspeakers Part 5. David Read | The moving cold loudspeaker. |
| 59 | Re-Inventing The Wheel. Desmond Thackeray | 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. |