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).
The performance, functionality, and pricing of the 'Radamax' plug tester.
| Identifier | ExFiles\Box 50\2\ Scan015 | |
| Date | 7th January 1921 | |
| Contd. -3- EFC {E. Fowler Clarke - Electrical Engineer} 1/T7.1.21. for 900 R.P.M. 3.8 mm. With a small gap of .003" sparking ceases at the sight-hole at all the above speeds. The spark at the main gap is always louder and more intense with the tester in position than normally. This is due to the effect of the capacity placed (through the sight-hole gap) in parallel with the main gap. The above observations were taken using a single gap without distributor. It will thus be seen that the "Radamax" takes some small portion of energy to operate it and therefore has less subtractive effect on a magneto spark than on that from the battery ignition. The "Radamax" plug tester tried on the car either on the battery ignition or on the magneto seems to be a very useful instrument. It is reported to us by the Experimental testers that it "functions quite well, even going so far as to give one warning when a plug is likely to give out. It is, however, rather unwieldy and is only able to be used where the sparking plug is easily got at". The price of this instrument we think is £1-1-0. The nett trade price of this instrument is 18/9. EFC. {E. Fowler Clarke - Electrical Engineer} | ||