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).
Table detailing the particulars of resistances and inductances for primary and secondary Goshawk ignition coils.
| Identifier | ExFiles\Box 45\4\ Scan289 | |
| Date | 20th May 1925 guessed | |
| X4653 X918 X4079 PARTICULARS OF RESISTANCES AND INDUCTANCES OF X.4079. PRIMARY AND SECONDARIES OF GOSHAWK IGNITION COILS. Coil. | PRIMARY | SECONDARY | Remarks. | Resis. (W) | Imped. at 50~ (W) | Reac. at 50~ (W) | Induc. (hys) | Resis. (W) | Imped. at 50~ (W) | Reac. at 50~ (W) | Induc. (hys) | GP1 | 1.90 | 5.23 | 4.87 | .0153 | 5080 | 16,150 | 15340 | 48.1 | Av. inductance .015 GP.2. | 1.94 | 5.23 | 4.86 | .0153 | 5265 | 16,300 | 15425 | 48.4 | FP.{F. Potts}1 | 1.76 | 4.43 | 4.06 | .0128 | 5210 | 16,030 | 15160 | 47.6 | .0125 FP.{F. Potts}2. | 1.84 | 4.39 | 3.99 | .0125 | 5380 | 16,150 | 15227 | 47.8 | | ||