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).
Instructions on the procedure for changing over the Wraith Coil.
| Identifier | ExFiles\Box 109\5\ scan0017 | |
| Date | 9th March 1938 | |
| 9.3.38. re Wraith Coil. A changeover from one coil to the other is made by pulling out the high tension lead from the centre chimney of the coil and replacing in the spare coil. This lead is located by means of a spring clip on the end of the lead, and only need be pushed to the bottom of the coil top to make connection. Also change over the two primary leads making sure they are not crossed. The top of the coil is marked to show the correct connection. RM{William Robotham - Chief Engineer}/RC.{R. Childs} | ||