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).
Production test for an ignition coil amended for a new ballast resistance.
| Identifier | ExFiles\Box 69\1\ scan0188 | |
| Date | 19th February 1929 | |
| BY.{R.W. Bailey - Chief Engineer} from FFC. c. Mr. Brock. c. Mx.{John H Maddocks - Chief Proving Officer} X8710 EFC2/LG19.2.29. PRODUCTION TEST OF IGNITION COIL. X.5710 Please find attached copy of production test for the 18,000 turns coarser primary coil duly ammended to suit the new k¾ value ballast resistance. FFC. | ||