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).
Instruction to experimentally make two 28 slot armatures for a 40/50 HP dynamo to address a noise issue.
| Identifier | ExFiles\Box 68\4\ scan0004 | |
| Date | 1st April 1927 | |
| To BY/RD. from EFC. c. BY CHARGE TO ORDER CHARGE TO EXPENSE X 8672 EFC5/T6.4.27. 28 SLOT ARMATURE FOR 40/50 HP. DYNAMO. With reference to our note EFC4/T6.4.27, will you now please instruct to have made experimentally two 28 slot 40/50 armatures with the same winding as in the case of the 20 HP. 28 slot armatures. You may remember there was some question of instructing this previously but we held it over for a time pending the results of tests on the 20 HP. 28 slot armatures. From the reports to hand it appears that these are consistently good for eliminating very nearly, but not quite, the troublesome noise. EFC. | ||