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 EKCO discussing the technical suitability of a Philips' Car Radio for installation.
| Identifier | ExFiles\Box 63\3\ scan0229 | |
| Date | 3rd January 1935 | |
| W. S. VERRELLS Chairman & Managing Director E.{Mr Elliott - Chief Engineer} K.{Mr Kilner} COLE Works & Technical Director E.{Mr Elliott - Chief Engineer} R.{Sir Henry Royce} PRING R.{Sir Henry Royce} E.{Mr Elliott - Chief Engineer} CORNWALL Directors EKCO ALL-ELECTRIC AND BATTERY RADIO TELEGRAMS EKCO SOUTHEND-ON-SEA TELEPHONE SOUTHEND 49491 8 Lines RIC/JP E.{Mr Elliott - Chief Engineer} K.{Mr Kilner} COLE LTD EKCO WORKS SOUTHEND-ON-SEA 3rd January 1935. Rolls Royce Ltd., DERBY. For the attention of Mr. West. Your Ref: Hs{Lord Ernest Hives - Chair}/Wst.4/MA. Dear Mr. West, Confirming my telephone conversation with you regarding your letter of the 12th ult., about Philips' Car Radio, we are grateful to you for bringing the interesting points about this equipment to our notice. We have in fact already investigated the points you mention, and our equipment includes a battery lead filter. With regard to the aerial filtering and damping arrangement used, we believe that the reduction of interference obtained by this means is to a great extent at the expense of sensitivity. We would suggest that as the ignition interference is, in any case, eliminated with comparative ease on Rolls Royce cars, a more conclusive test of the aerial filtering principle would be obtained if you try the equipment on your Triumph car. With regard to the current consumption, firstly, measurement of the current taken by the example we have examined showed that it was not 2.4 amps but 3.6 amps and the vibrator "valve" has, of course, no heater. Looking at the question of current consumption from a power output point of view we find that particularly in a heavily upholstered limousine interior, where the absorption is very high, it is necessary to have an undistorted output of 4-watts available. This means an anode dissipation of 10 to 12-watts to which must be added, say, 8-watts H.T. for all the remaining valves in the receiver, giving a total of 20-watts, which has then to be multiplied by 2 to allow for an L.T./H.T. conversion efficiency of 50%, which efficiency is rarely exceeded in practice with vibrator or rotary convertor. IMPORTANT NOTICE "LIMITED LICENCE" "Ekco products are patented and are supplied upon condition that the recipient accepts a licence under the patents and agrees to sell only at the prices fixed by the Makers. Violation of this by anyone renders him liable for damages." | ||