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).
Use of ballast resistance with coarser primary winding ignition coils.
| Identifier | ExFiles\Box 69\1\ scan0083 | |
| Date | 16th May 1928 | |
| X8710 To EY/RD. from EFC. EFC3/T16.5.28. IGNITION COILS. Answering your EY/RD1/ML16.5.28, we are not in a position to recommend the use of the double value ballast resistance with the coarser primary winding coil at the moment, but have been and are still are making some tests and shall have the arrangement running on a 10,000 mile test. Therefore we will do as you suggest, viz. use the old ballast resistance with this coarser primary coil. EFC. | ||