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).
Confirming a change in the manufacturing process for the ballast resistance from brazing to soldering.
| Identifier | ExFiles\Box 168a\5\ img051 | |
| Date | 5th February 1931 | |
| X7720. Ev.{Ivan Evernden - coachwork} from EFC. c. Sft{Mr Swift}/Mr.Brock. EFC3/AD5.2.31. X.7720. BALLAST RESISTANCE. We agree from tests we have made that the ballast resistance can be made with the wire ends soldered to the terminal tags instead of brazed as hitherto. The solder does not attain sufficiently high temperature to melt in normal operation and a test of a ballast resistance so made up for a considerable time on a car has been quite satisfactory. EFC. | ||