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 to E.K.Cole Ltd. regarding testing a car radio set and suppressing ignition interference.
| Identifier | ExFiles\Box 63\3\ scan0217 | |
| Date | 12th December 1934 | |
| Y 6153 Hs{Lord Ernest Hives - Chair}/Wst.4/MA. 12th December, 1934. Messrs.E.K.Cole, Ltd., Ekco Works, Southend-on-sea. Dear Sirs, We have recently been testing a car radio set in which the use of suppressors on the sparking plugs is entirely eliminated. This is of particular interest to us as we experience a lot of ignition trouble directly attributable to the fitting of suppressors. The ignition interference was suppressed by the use of filters inserted in the aerial and battery feed wires designed to filter any oscillations above a certain value corresponding to a wave length of 200 metres. A further point of interest was the fact that a vibrator unit was installed operating in an inert gas to avoid contact point troubles. The performance of this receiver was remarkable in that there was no extraneous interference and the battery feed current was only 2.4 amperes, this for a six valve superhet. We suggest to you that the elimination of suppressors without the addition of electrostatic screening on the ignition system is a most desirable feature and we wonder if you have considered incorporating anything of this nature in your own car radio receivers. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||