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).
Requesting the production of an experimental ignition coil with 20,000 turns instead of the standard 18,000.
| Identifier | ExFiles\Box 69\1\ scan0190 | |
| Date | 4th April 1929 | |
| X.8710 To Mr. Brock. from EFC. EFC/T4.4.29. IGNITION COIL. The 20,000 turn coil with which you provided us to our instruction EFC/T2.2.29 has also paraffin wax paper insulation which we did not require. We would like you to wind another coil for us to O/N.54733 precisely as present standard production with the one exception - that it has 20,000 turns in place of 18,000. This is a variation with which we have not experimented so far, and we are desirous of observing the effect of the additional 2000 turns on an otherwise exactly standard coarser gauge primary coil. EFC. | ||