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).
Price confirmation for a Johnson & Philips full wave converter.
| Identifier | ExFiles\Box 32\5\ Scan022 | |
| Date | 24th December 1925 | |
| X.1589. 24.12.25. Price of Johnson & Philips full wave converter = £8.10.0. nett. EFC. | ||