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).
Experimental modifications to the 'Goshawk' 11 Coil for Battery Ignition 'B' Type, regarding changes to the insulation paper.
| Identifier | ExFiles\Box 45\4\ Scan009 | |
| Date | 3rd March 1922 | |
| R.R. 189 (880 H) (BD.{Mr Berend} 296. 15.9.17) M.P. 176549. WHC. c. to Sft.{Mr Swift} EFC. XH4079a BY/WER2/EF3. 3. 22. EXPERIMENTAL X. 4079:- "GOSHAWK" 11. COIL FOR BATTERY IGNITION "B" TYPE Our memo BY/WER9/EF2B. 2. 22 instructing three or four experimental coils to be made to I.O.F. D.50210 but to be wound in accordance with particulars contained in that memo. These instructions still remain good, but we wish to make still further modifications to these coils. The winding drawing D.50452 at present calls for the insulation between each layer of the secondary winding to be three layers of .001 oil paper. Actually the works use 2 layers of .0015 oil paper. We now wish to use two layers of .00075 oil paper to be the same quality as that we have obtained from America for making the Condenser Rolls. The O.C. are enquiring for this paper in the correct width 2.215 but some time will elapse before this paper is received. In the meantime we would like you, for these Coils which you are making, to use the oil paper which was bought for the Condensers. This is really too wide being 2.325 wide, but we think can be cut down to suit. With this new quality and thickness of paper of paper we consider that more than the specified number of turns of secondary winding i.e. 21000 can be wound, we probably, if EFC desires it we can get something like 27000. We hope that the new primary winding with more robust insulation and the thinner paper allowing for more secondary turns will result in this coil being the best which has so far been produced. BY/WER. WER RECEIVED MAR 3 1922 H8 | ||