Mullard output triode valve, type D.F.A.6., B4 base, painted C89 Onyx, filament broken, glass envelope loose, (RMW/D59 - McVitie Weston number), by Mullard Limited, 1929.
Mullard output triode valve, type D.F.A.6., B4 base, painted C89 Onyx, filament broken, glass envelope loose, (RMW/D59 - McVitie Weston number), by Mullard Limited, 1929.