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).
Production inspection and test log for a Watford Type EW6 Magneto.
| Identifier | ExFiles\Box 65\3\ scan0185 | |
| Date | 3rd February 1928 | |
| H.E.W. X7791 X. 9781m. WATFORD TYPE EW6 MAGNETO. X. 7791. PRODUCTION INSPECTION AND TEST. Date. (1) Magneto No. Remarks. (2) Range (degrees) (>58°) (3) Remarks. (4) Tangl. force. 1 to 2 lbs. (5) Remarks. (6) Remarks. (7) Min. sparking speeds (a) (b) (c) <120 <160 <190 10-12-28 | 114790 | OK | — | OK | — | OK | OK | 75 | 135 | 205 12-12-28 | 114789 | OK | 60° | OK | 1/2 lb. | OK | OK | 60 | 110 | 180 12-12-28 | 115305 | OK | — | OK | 1 1/2 lbs. | OK. | OK | 70 | 120 | 175 12-12-28 | 114787 | OK | 60° | OK | 3/4 lb. | OK | OK | 65 | 105 | 170 12-12-28 | 115304 | OK | — | OK | — | OK | OK | 60 | 105 | 165 17-12-28 | 106012 | OK | -60° | OK | — | OK | OK | 70 | 105 | 170 16-4-29 | 117445 | OK | 60° | OK | — | OK | OK | 65 | 110 | 170 16-4-29 | 117446 | OK | — | OK | — | OK | OK | 75 | 120 | 180 3.2.28. | ||