| Description | Date | Identifier | |
| Proposal for mounting and engraving a spare ignition coil for a Bensport. | 20th Apr 1933 | Box 164 \ 5 img175 | |
| Requesting clarification on the circumstances of ignition coil failures on experimental cars. | 10th Jun 1933 | Box 164 \ 5 img176 | |
| Ignition coil failures on a Bensport engine test bed. | 12th Jun 1933 | Box 164 \ 5 img177 | |
| Request for a special standard ignition coil with a modified third terminal. | 6th Oct 1933 | Box 164 \ 5 img178 | |
| Letter to Professor G.I. Finch requesting oscillograms of a standard ignition coil. | 7th Oct 1933 | Box 164 \ 5 img179 | |
| Letter from Imperial College of Science and Technology regarding the taking of oscillograms. | 13th Oct 1933 | Box 164 \ 5 img180 | |
| Letter arranging to provide an exact date for a future meeting. | 16th Oct 1933 | Box 164 \ 5 img181 | |
| Letter from Ford Motor Company Ltd providing the address for the Mallory Electric Corporation. | 16th Oct 1933 | Box 164 \ 5 img182 | |
| New design for an ignition coil to prevent secondary winding breakdowns. | 19th Oct 1933 | Box 164 \ 5 img183 | |
| Letter to Professor Finch at Imperial College regarding the testing of an ignition coil. | 21th Nov 1933 | Box 164 \ 5 img184 | |
| Letter on Imperial College of Science and Technology letterhead regarding the testing of two coils. | 22th Nov 1933 | Box 164 \ 5 img185 | |
| Letter arranging for a Mr. Hives to visit Derby and travel to Ferrantis in Hollinwood for urgent work. | 22th Nov 1933 | Box 164 \ 5 img186 | |
| Letter fragment on Imperial College letterhead regarding electrical ignition problems. | 22th Nov 1933 | Box 164 \ 5 img187 | |
| Arranging a Sunday time-table. | 23th Nov 1933 | Box 164 \ 5 img188 | |
| Letter to Professor Finch of Imperial College arranging a visit for Mr. Mole to conduct oscillographs on coils. | 23th Nov 1933 | Box 164 \ 5 img189 | |
| Letter from Imperial College of Science and Technology arranging a meeting in Derby. | 24th Nov 1933 | Box 164 \ 5 img190 | |
| Arranging a meeting to discuss the results of a cathode-ray oscillographic investigation of ignition coils. | 26th Jan 1934 | Box 164 \ 5 img191 | |
| Ignition coil failures, their cause, and proposed solutions for improved winding methods. | 26th Jan 1934 | Box 164 \ 5 img192 | |
| Modifications to an ignition coil to reduce self-capacitance and ionization issues. | 26th Jan 1934 | Box 164 \ 5 img193 | |
| Revised production test for Ignition Coil D.72503. | 1st Feb 1934 | Box 164 \ 5 img194 | |
| Production test specification for an ignition coil and ballast resistance. | 31th Jan 1934 | Box 164 \ 5 img195 | |
| Test procedure for a coil, detailing voltage, duration, and performance criteria. | 31th Jan 1934 | Box 164 \ 5 img196 | |
| Production test and inspection procedure for a ballast resistance for an ignition coil. | 27th Jan 1934 | Box 164 \ 5 img197 | |
| Unsuitability of an 'OKONITE' sample for use on ignition coils due to risk of ionization damage. | 27th Jan 1934 | Box 164 \ 5 img198 | |
| Letter from Imperial College of Science and Technology arranging a meeting in Derby. | 13th Feb 1934 | Box 164 \ 5 img199 | |
| The production of 6 'Spectre' Ignition Coils, detailing specific materials to be ordered for the primary winding. | 20th Feb 1934 | Box 164 \ 5 img200 | |
| Investigation into a customer complaint of fumes from a voltage regulator coil on a Bentley chassis and proposed solutions. | 21th Feb 1934 | Box 164 \ 5 img201 | |
| Dispatch of a dynamo voltage regulator resistance coil for testing purposes. | 5th May 1934 | Box 164 \ 5 img202 | |
| Specifying the material for new ignition coil cores to be .012' thick 'Stalloy' sheet. | 17th May 1934 | Box 164 \ 5 img203 | |
| Design, positioning, and standardization of spare Bentley Coils. | 31th May 1934 | Box 164 \ 5 img204 | |
| Request to arrange the fitting of a spare ignition coil on a Bentley Chassis. | 1st Jun 1934 | Box 164 \ 5 img205 | |
| Alternative design scheme for Bentley ignition coils and their associated switching. | 4th Jun 1934 | Box 164 \ 5 img206 | |
| Instruction memo to fit a new twin coil scheme and radio suppressors to chassis 3.B.IV. | 26th Jun 1934 | Box 164 \ 5 img207 | |
| Requesting an update on the readiness of the double ignition coil scheme for Bentley production. | 22th Jun 1934 | Box 164 \ 5 img208 | |
| Requesting the production of six more 'Spectre' type ignition coils. | 27th Jul 1934 | Box 164 \ 5 img209 | |
| Standardisation of two ignition coils with knurled nut terminals mounted on the wheelcase. | 21th Aug 1934 | Box 164 \ 5 img210 | |
| Cost and scrap analysis for the standardisation of Bentley parts. | 27th Jul 1934 | Box 164 \ 5 img211 | |
| Temporary modification to the 'Spectre' Ignition Coils for improved cooling. | 6th Oct 1934 | Box 164 \ 5 img212 | |
| Testing a new grade of ignition coil insulating paper as a replacement for an out-of-stock grade. | 28th Dec 1934 | Box 164 \ 5 img213 | |
| Request to supply three Spectre ignition coils to drawing D.74200. | 17th Jan 1935 | Box 164 \ 5 img214 | |
| Mounting of ignition coils for the Spectre engine, detailing a new crankcase design. | 17th Jan 1935 | Box 164 \ 5 img215 | |
| Request to rewind the primary winding of an ignition coil for testing purposes. | 25th Feb 1935 | Box 164 \ 5 img216 | |
| Inquiring about the modification to the position of the Spectre ignition coils. | 2nd Mar 1935 | Box 164 \ 5 img217 | |
| Instruction to mount ignition coils on Spectre engines on raised distance pieces for extra cooling. | 4th Mar 1935 | Box 164 \ 5 img218 | |
| Secret memo regarding the decision to continue with a raised coil position on the Spectre project, pending a crankcase alteration. | 4th Mar 1935 | Box 164 \ 5 img219 | |
| Experimental Stalloy core to improve the high-speed performance of the Spectre ignition coil D.74200. | 8th Mar 1935 | Box 164 \ 5 img220 | |
| Feasibility of replacing a Swedish iron wire core with a Stalloy plate core for a 'Spectre' ignition coil. | 28th Mar 1935 | Box 164 \ 5 img221 | |
| Clarifying that improvements to the Spectre Ignition Coil B.74200 are expected from a change of material. | 29th Mar 1935 | Box 164 \ 5 img222 | |
| Request to rewind an ignition coil's primary winding with specific wire and turn parameters. | 29th Mar 1935 | Box 164 \ 5 img224 | |
| Requesting the changeover of ignition coils on Spectre 2 and 3 to test new 'Seekay' wax. | 4th May 1935 | Box 164 \ 5 img225 | |
| Testing a new high melting point impregnating wax, 'Seekay', for ignition coils. | 4th May 1935 | Box 164 \ 5 img226 | |
| Use of 'Seekay' wax for ignition coils and coordinating with Imperial Chemical Industries. | 7th May 1935 | Box 164 \ 5 img227 | |
| Raising the coils on the experimental Spectre chassis for extra cooling and accessibility. | 13th Jun 1935 | Box 164 \ 5 img228 | |
| Specification and parts list for the 'Spectre' Ignition Coil, Section 8140. | 1st Jul 1935 | Box 164 \ 5 img229 | |
| Letter from Delco-Remy & Hyatt Ltd. regarding controller coils, with a handwritten reply explaining a delay in testing. | 16th Jul 1933 | Box 164 \ 5 img230 | |
| Letter to Delco-Remy & Hyatt, Ltd. regarding a delay in testing Delco Ignition-Controller Coils. | 19th Jul 1935 | Box 164 \ 5 img231 | |
| Letter from Delco-Remy & Hyatt Ltd. regarding a test on Delco Ignition Controller Coils. | 25th Jul 1935 | Box 164 \ 5 img232 | |
| Instruction memo regarding the filling of Spectre coils with 'Seekay' wax at a specific temperature. | 12th Aug 1935 | Box 164 \ 5 img233 | |
| Request for a further ignition coil with altered primary and secondary winding specifications. | 16th Aug 1935 | Box 164 \ 5 img234 | |
| Letter from Imperial Chemical Industries enclosing a specification for Seekay Wax Grade R.93c. | 30th Aug 1935 | Box 164 \ 5 img235 | |
| Suggested specification for the electrical properties of Seekay Wax R.93 C, provided by Imperial Chemical Industries Limited. | 26th Feb 1935 | Box 164 \ 5 img236 | |
| The conditions of test and values for Power Factor and Volume Resistivity. | 26th Feb 1935 | Box 164 \ 5 img237 | |
| Internal request to order 28 ignition coil type suppressors from Erie Resistor Co. | 9th Sep 1935 | Box 164 \ 5 img238 | |
| Mr. Brock's objections to hand-filling ignition coils with Seekay wax and agreeing to vacuum impregnation instead. | 20th Sep 1935 | Box 164 \ 5 img239 | |
| Filling ignition coils with I.C.I. 'Seekay' wax. | 23th Sep 1935 | Box 164 \ 5 img240 | |
| Technical report on the testing of I.C.I. 'Seekay' wax for filling ignition coils to improve reliability. | 23th Sep 1935 | Box 164 \ 5 img241 | |
| Instruction to impregnate all ignition coils in vacuo using Seekay Wax. | 24th Sep 1935 | Box 164 \ 5 img242 | |
| Internal order request for various insulating tubes and insulators for an aero ignition coil. | 4th Dec 1935 | Box 164 \ 5 img243 | |
| Request for performance curves for the Williams Patent Super Coils from The Super Coil Co. | 5th May 1936 | Box 164 \ 5 img244 | |
| The purchase of two 12-volt ignition coils from S.J. Williams & Co. | 7th May 1936 | Box 164 \ 5 img245 | |
| Modifications to a governor for 'Hall's Unit' (B-21) to achieve the ideal advance line for a trial. | 13th May 1936 | Box 164 \ 5 img246 | |
| Internal request to place an order for 12-volt B.T.H. and Rotax aero booster coils. | 3rd Jul 1936 | Box 164 \ 5 img247 | |
| Composition and harmful effects of Seekay Wax for ignition coils and evaluating Halowax as an alternative. | 4th Aug 1936 | Box 164 \ 5 img248 | |
| Enquiry into the composition of Halowax for coil ignition. | 12th Aug 1936 | Box 164 \ 5 img249 | |
| Replacing Seekay wax with Halowax for insulating ignition coils due to operator health concerns and material incompatibility. | 1st Sep 1936 | Box 164 \ 5 img250 | |
| Requesting modifications to an ignition coil for use with increased plug gaps. | 12th Aug 1936 | Box 164 \ 5 img251 | |
| Unsatisfactory Watford 12-volt booster coil, type NIKA, supplied by Messrs. Rotax Ltd. | 31th Aug 1936 | Box 164 \ 5 img252 | |
| Request to examine a failed coil from a Bentley car by dismantling it. | 22th Oct 1936 | Box 164 \ 5 img253 | |
| Request to manufacture a modified Phantom III ignition coil with 15000 turns on the secondary winding. | 23th Oct 1936 | Box 164 \ 5 img254 | |
| The examination of a faulty ignition coil, which found the cause to be a fractured wire connection. | 26th Oct 1936 | Box 164 \ 5 img255 | |
| Request to produce two ignition coils with reversed polarity for the Phantom III. | 5th Nov 1936 | Box 164 \ 5 img256 | |
| Letter from Delco-Remy & Hyatt Ltd. regarding the supply of sample distributors and 12-volt ignition coils. | 4th Nov 1936 | Box 164 \ 5 img257 | |
| Arranging the despatch of an R.R. Ignition Coil to Delco-Remy & Hyatt Ltd for examination. | 13th Nov 1936 | Box 164 \ 5 img258 | |
| Letter to Delco-Remy & Hyatt Ltd. requesting to hold the supply of ignition coils and sample distributors. | 6th Nov 1936 | Box 164 \ 5 img259 | |
| Letter from Bakelite Limited following up on a sample of 'HALOWAX' W.1004 sent for ignition coil impregnation experiments. | 17th Nov 1936 | Box 164 \ 5 img260 | |
| Experimental department report on improvements to ignition coils. | 7th Dec 1936 | Box 164 \ 5 img261 | |
| Two experimental modifications to improve standard ignition coils. | 7th Dec 1936 | Box 164 \ 5 img262 | |
| Graph showing test results for the effect of short circuit secondary turns on a coil under different loads. | 7th Dec 1936 | Box 164 \ 5 img263 | |
| Graph comparing the performance of a modified ignition coil against the original under different loads. | 9th Dec 1936 | Box 164 \ 5 img264 | |
| Letter to Bakelite Ltd. regarding the unsuitability of 'Halowax' for ignition coil impregnation due to its high inductivity. | 9th Dec 1936 | Box 164 \ 5 img265 | |
| The fitting of a special Delco Remy coil to two chassis for testing purposes. | 21th Jan 1937 | Box 164 \ 5 img266 | |
| Request for the design and manufacture of two adaptor brackets for fitting Delco Remy coils to specific chassis. | 27th Jan 1937 | Box 164 \ 5 img267 | |
| Request to rewind a special Wraith ignition coil with new specifications. | 2nd Mar 1937 | Box 164 \ 5 img268 | |
| The fitting of ignition coils to new Wraith chassis. | 2nd Mar 1937 | Box 164 \ 5 img269 | |
| Request to re-wind two ignition coils with a modified specification for the secondary winding. | 25th Mar 1937 | Box 164 \ 5 img270 | |
| On the Wraith Ignition Coil, proposing to standardise it by using aero coil windings for chassis work. | 5th Apr 1937 | Box 164 \ 5 img271 | |
| Recommending a new combined ignition coil and distributor for the Phantom III chassis. | 6th Apr 1937 | Box 164 \ 5 img272 | |
| Improved and cheaper secondary winding for D.75672 coils, requesting a new drawing. | 10th Apr 1937 | Box 164 \ 5 img273 | |
| Instruction to mould six coil cases as per drawing D.75672. | 7th Apr 1937 | Box 164 \ 5 img274 | |
| The estimated costs for manufacturing coil part number D.75673. | 3rd May 1937 | Box 164 \ 5 img275 | |
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