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).
Upcoming legislation on the suppression of radio interference from motor cars.
| Identifier | ExFiles\Box 168b\1\ img153 | |
| Date | 20th January 1939 | |
| CHILDS 6153 To EY. Da.{Bernard Day - Chassis Design} Rm.{William Robotham - Chief Engineer} Please arrange Pm BY/RD.1/B. 20.1.39. LEGISLATION ON SUPPRESSION OF RADIO INTERFERENCE. The specification on suppression is now going forward, and it is likely that the Motor Car Manufacturers will be required to produce cars which do not radiate any interference. As far as our information goes at present, it would appear that a level of interference of 50 microvolts/meter at the television frequency measured 10 yards from the vehicle will be required. This will most likely mean that we shall be required to fit a suppressor in the high tension lead between the ignition coil and distributor and maintain the coil as close to the ignition distributor as possible. We suggest that this arrangement should be rigged up on as many experimental cars as possible in order that any disadvantages may show up. In assessing the benefits coming from the general agreement to a limit of 50 microvolts/meter, roughly it would increase the range of the Alexandra Park transmitter and other transmitters proposed, about twice, and would also be of material assistance to the Air Ministry, Post Office and War Department. BY/RD | ||