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).
Comparison table of magneto tests showing volt-ampere capacity and figure of merit.
| Identifier | ExFiles\Box 4\5\ 05-page338 | |
| Date | 14th April 1928 | |
| Chassis magnetos MAGNETO TESTS - VOLT AMPERE CAPACITY AND FIGURE OF MERIT. Magneto. | Type. | No. | Volt-ampere capacity. | Figure of merit. Scintilla | GN6 | 57927 | 20.0 | 1.45 " | AM6A | 34937 | 16.15 | 1.29 R.{Sir Henry Royce} Bosch | ZFG | 2490573 | 19.8 | 1.65 B.T.H | FMG | 356071 | 38.5 | 3.32 Simms | SR6L | 127505 | 67.8 | 3.69 " | SR6L | 135985 | 61.8 | 3.90 Watford | E6 | 40886 | 28.3 | 2.42 " | E06 | 82558 | 32.9 | 2.63 14.4.28. | ||