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 the use of paper insulation and no varnish for the primary winding on 40/50 Stabalite coils for Goshawk.
| Identifier | ExFiles\Box 49\5\ Scan027 | |
| Date | 21th August 1923 | |
| x4273 To Ry/Ds. from EFC. {E. Fowler Clarke - Electrical Engineer} c. Mr. Brock. EFC {E. Fowler Clarke - Electrical Engineer} 3/T21.8.23. X.4273 - 40/50 STABALITE COILS FOR GOSHAWK. This is to confirm that as arranged in conversation, in all further coils of the unlengthened 40/50 type which are going through for production, in which we are now including paper insulation between the primary layers, no varnish will be used on the primary winding. EFC. {E. Fowler Clarke - Electrical Engineer} | ||