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).
Instruction sheet detailing the testing and characteristics of a Klaxon two-note horn, model S20774.
| Identifier | ExFiles\Box 59\3\ Scan092 | |
| Date | 2nd December 1930 | |
| RR. 218 (150 BKS.) (DB{Donald Bastow - Suspensions} 461-8-12-24) N P 3C6975 X6075 ROLLS-ROYCE LTD. INSTRUCTIONS. To: FFC Order No.: AD 74 Customer's No.: x/H/1/C Klaxon Two-note Horn. S20774. This horn was received under cover of Ex/Hdy{William Hardy} 1/MJV. 26.11.30. It is similar in external appearance to the two-note horn described in AD31 of 22.3.29. the resistances however are higher. Insulation OK. High Low Coil resistances 1.26 ohms 2.10 ohms Current to break contacts 3.6 amps Running current on 12V. 1.5 amp 0.8 amp Minimum working volts 6.0 9.0 Pitch (vibrations per sec) 300 290 Intensity and quality are similar to the other Klaxon samples. The low note is very little lower in pitch than the high but is considerably quieter, the period of these horns being determined mechanically rather than electrically. Signed: J.S.A. This Sheet must be filed on completion of the work. | ||