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).
General notes and instructions regarding the installation of radio receiving sets on chassis.
| Identifier | ExFiles\Box 63\2\ scan0092 | |
| Date | 6th August 1935 guessed | |
| GENERAL NOTES AND INSTRUCTIONS REGARDING THE INSTALLATION OF RADIO RECEIVING SETS ON ROLLS-ROYCE AND BENTLEY CHASSIS. (1) Connection of set to car electrical system. The negative supply to the set is usually earthed to the metal case so that bolting the set to the dashboard automatically earths it to our frame. The positive feed wire should be connected to the bottom terminal of one of the two accessory fuse terminals. These are clearly marked and separated by a small division from the other fuses. On some sets the makers supply a filter unit to be placed in series with the positive feed to the set and the supply terminal on the car. This is only permissible if the filter unit is bolted securely to the dashboard and has no exposed live terminals. It is preferable not to connect the feed wire to the accessory terminal to which the cigar lighters, or other heavy current accessories, are connected. This is usually the end fuse of the two. The cable used for wiring the set to this terminal should be best quality C.M.A grade flexible cable 40/36 conductor. (2) Noise suppression. Condensers are permitted to be fitted only where necessary (see sketch attached), as follows :- (a) At the positive main terminal on the dynamo, i.e. the terminal to which the black wire is attached. On no account must a condenser be fitted to the field terminal to which the black and white cable is attached. (b) At the ballast resistance terminal connecting the ballast resistance to the ignition coil. (Not the one with the conductor coming up from the chassis frame.) (c) On certain types of bodies interference may arise due to the body wiring. Where this is apparent a condenser may be fitted to the bottom terminal of No.6 fuse or the accessory fuses, as the necessity arises; always the bottom terminals of these fuses. | ||