McVitie Weston valve collection, Mullard ORA valve
- Made:
- 1923
- maker:
- Mullard Limited
Mullard ORA valve, reversed spiral grid formation, filament broken, (RMW/B115A - McVitie Weston number), by Mullard Limited, 1923.
Mullard ORA valve, reversed spiral grid formation, filament broken, (RMW/B115A - McVitie Weston number), by Mullard Limited, 1923.