McVitie Weston valve collection, Marconi valve, type D.E.T.1
- maker:
- Marconi Company Limited
Marconi valve, type D.E.T.1, marked 683X, pinch marked 7903, filament broken, (RMW/J33 - McVitie Weston number), by Marconi Company Limited.
Marconi valve, type D.E.T.1, marked 683X, pinch marked 7903, filament broken, (RMW/J33 - McVitie Weston number), by Marconi Company Limited.