Board supporting two Ayrton-Mather non-induction spiral coils Board supporting two Ayrton-Mather non-induction spiral coils
A collection of four electrical valves; large from the early period (triodes, rectifiers). These are Type GAT9 (water cooled triode), CV19 (rectifier), ACT9 (rectifier), V1505 (triode). Mostly large size, one with black cooling grid on it. valve