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 The Telegraph Condenser Company discussing the suitability of different condensers for car radio noise suppression.
| Identifier | ExFiles\Box 63\3\ scan0333 | |
| Date | 16th April 1935 | |
| The Telegraph Condenser Company, Limited. PHONE: ACORN 0061 (6 LINES) GRAMS: 'TELEFARAD, PHONE, LONDON' CODE: BENTLEY'S DIRECTORS: LORD EBBISHAM, G.B.E. E.{Mr Elliott - Chief Engineer} H.{Arthur M. Hanbury - Head Complaints} F.{Mr Friese} REEVES. S. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} BROWN, F.R.S. MRS A.{Mr Adams} S. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} BROWN. W. J.{Mr Johnson W.M.} COLE, (MANAGING) Handwritten top: 26153. Wales Farm Road, North Acton, London, W.3. YOUR REF Hs{Lord Ernest Hives - Chair}/Wst.5/MA. OUR REF CDG/SK. 16th April 1935. Messrs. Rolls-Royce Ltd., DERBY. Handwritten center: WST Handwritten left margin: OK for dynamos. wipers. Petrol pump Dear Sirs, Car Radio In reply to your enquiry of 11th April we have an electrolytic condenser 1 mfd capacity suitable for working up to 450 volt peak which is contained in a paxolin tube 2" long by 11/16" diameter. If this is required in a metal container then a slight increase in size is necessary. We believe however, that for noise suppression, impregnated paper dielectric condensers are more suitable particularly for radio frequency duty and we are therefore supplying particulars of various capacities and voltages in order that you may compare these with one another and with the electrolytic condenser. We would point out that with electrolytic condensers the usual margin of safety is not allowed; breakdown occurs at a voltage only about 25% in excess of the rated working voltage whereas with paper dielectric condensers the ratio of breakdown to working is of the order of 10 to 1. We look forward to your remarks when you have had an opportunity of considering these particulars. Yours faithfully, THE TELEGRAPH CONDENSER CO. LTD. [Signature] ENC. ALL COMMUNICATIONS TO BE ADDRESSED TO THE COMPANY. | ||