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).
Letter from E.K. Cole Ltd. regarding car radio filters and suppression equipment.
| Identifier | ExFiles\Box 63\3\ scan0339 | |
| Date | 24th April 1935 guessed | |
| - 2 - Rolls Royce Ltd., terminals of the main distributor box we normally use one of our type "D" filters, the mechanical construction of which you have already approved verbally. This filter consists of two 25mfd. condensers suitably mounted in a metal box and we consider that this is neater and safer electrically and mechanically than two separate condensers independently mounted. You already have one of these filters in the standard suppression equipment supplied with the receiver. The inductive filter type "A" which includes the fuse for the receiver, is normally wired between the body wiring distributor box on the chassis and the receiver. The inductive filters "B" and "C" are designed for the ignition coil and windscreen wiper respectively, but neither of these are normally necessary on Rolls Royce cars. We should like your approval for their use, however, in cases where bad interference is experienced. In no circumstances do we ever find it either necessary or desirable to fit condensers across the voltage control units, and should a particularly difficult or erratic unit be found on a car to be fitted with radio, we shall communicate with your Service Department, and request that this be changed in accordance with your instructions. We will communicate with you again as soon as we get the exact type of condenser which you specify. Yours faithfully, For and on behalf of E.K.Cole Ltd., Rex Cowley CAR RADIO ENGINEER. | ||