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).
Test results for a Lucas H.F. electric horn, noting its pitch and frequency compared to experimental models.
| Identifier | ExFiles\Box 59\3\ Scan185 | |
| Date | 12th July 1932 | |
| X6032 BY/RD. From Hs{Lord Ernest Hives - Chair}/Wst. c. Mx.{John H Maddocks - Chief Proving Officer} Hs{Lord Ernest Hives - Chair}/Wst.4/MA.12.7.32. LUCAS H.F. ELECTRIC HORN. We have tested the proposed standard horn submitted and find that it is half a tone lower in pitch than all our experimental horns i.e. D "natural" instead of D "sharp". The percentage drop in frequency is 5.3. As this test was taken at a nominal 12 volts and there will probably be an increase in pitch frequency of about 5% with the battery at its maximum voltage, we agree that this horn is OK. Too high a frequency makes a horn unpleasant. to the driver. Hs{Lord Ernest Hives - Chair}/Wst. | ||