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).
List of seven key requirements for the design and function of a car radio.
| Identifier | ExFiles\Box 168b\1\ img199 | |
| Date | 13th July 1939 guessed | |
| (4). The casing should be such as to give the maximum screening, be dust proof, but must be able to be easily mounted and dismounted for servicing. (5). Tuning, switching and volume control must be of the simplest. (6). The Radio circuit must be extremely sensitive to make up for low aerial height, but must be balanced at all times. (7). The Audio output level must be constant and up to house radio standard. The foregoing seven points pretty well cover the specialised field of the car Radio, as distinct from the common features which are a part of all modern Radio Sets, which are Super-hetrodyne, plus various refinements used today, i.e. A.V.C., remote control, etc.etc. 1. | ||