From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Cross-reference note regarding a thermionic rectifying valve for H.T.
| Identifier | ExFiles\Box 41\2\ Scan088 | |
| Date | 31th December 1930 | |
| X.3646. 31.12.30. For further matter relating to Thermionic rectifying valve for H.T. see X.6094. | ||