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).
Comparison of a new magneto's performance and screening method against existing B.T.H. types.
| Identifier | ExFiles\Box 43\4\ Scan143 | |
| Date | 15th October 1928 guessed | |
| -2- Contd. testing of the electrical performance, the magneto (No.98033) with a larger make-ratio and timed earlier giving a better lowe speed performance whilst not losing much at high speeds, i.e. the high speed performance still being good. The weight of these magnetos complete with screen is approx. the same as the latest lightened type B.T.H. magnetos. We consider the scheme adopted by Messrs. North for screening the magneto to be better than the B.T.H. from the engine assembler's point of view, as the wiring up does not necessitate the removal of the distributor block. Also the screening is more complete as the metal screen, which is an aluminium alloy casting, fits tightly into the main body of the magneto, and the cable thimbles or sleeves are gripped more securely without any bulging occurring which would allow leakage of oscillatory currents detrimental to the airplane wireless receiving apparatus. There are also no screws inside the distributor block as on B.T.H., the starting magneto cable being located on the outside. We shall be interested to see how these magnetos fare on an engine, as compared with the B.T.H., particularly at low speeds. EFC. | ||