| Description | Date | Identifier | |
| The performance of tungsten contact points and the required condenser capacity following experimental testing. | 10th Oct 1930 | Box 61b \ 1 scan0129 | |
| The performance of ignition distributor contact points and condensers, investigating different dielectric materials. | 14th Oct 1930 | Box 61b \ 1 scan0130 | |
| Test report on the effects of different condenser capacities on screw point oxidation in a distributor unit. | 4th Oct 1930 | Box 61b \ 1 scan0131 | |
| Analysis of condenser capacity tests on 20/25 HP and Phantom II chassis to resolve misfiring complaints. | 14th Oct 1930 | Box 61b \ 1 scan0132 | |
| Extract from a report on the 18-GIV model at 6,000 miles, detailing distributor issues. | 18th Dec 1930 | Box 61b \ 1 scan0133 | |
| Design considerations for ignition coils and magneto armatures using tungsten points on the contact breaker. | 1st Apr 1930 | Box 61b \ 1 scan0134 | |
| Letter to Mr. Minchin discussing ignition duplication, misfiring, and condenser capacity for tungsten versus platinum points. | 24th Sep 1930 | Box 61b \ 1 scan0135 | |
| Letter to Messrs. Peto & Radford regarding the testing of lower capacity condensers to address misfiring. | 24th Sep 1930 | Box 61b \ 1 scan0136 | |
| Request to send in a condenser and contact points from chassis 18-GIV for examination. | 2nd Jan 1931 | Box 61b \ 1 scan0137 | |
| Distributor contact points and condenser performance after a 10,000-mile test on vehicle 18-GIV. | 30th Jan 1931 | Box 61b \ 1 scan0138 | |
| Performance and capacity of paraffin waxed paper condensers for ignition systems. | 19th Feb 1931 | Box 61b \ 1 scan0139 | |
| Letter from a repair department requesting assistance with a recurring engine misfire on a 20 HP car, model GLN-61. | 19th Feb 1931 | Box 61b \ 1 scan0140 | |
| Tests on a battery ignition contact breaker to determine when sparking occurs. | 20th Feb 1931 | Box 61b \ 1 scan0141 | |
| Fault with battery ignition tungsten contact points, suggesting the old pair be returned for examination. | 25th Feb 1931 | Box 61b \ 1 scan0142 | |
| Test report on a Marelli distributor and contact breaker, comparing it to a Delco Remy design. | 1st Mar 1931 | Box 61b \ 1 scan0143 | |
| Observations and further investigation plans following a test on a distributor unit. | 1st Mar 1931 | Box 61b \ 1 scan0144 | |
| Request for the removal of tungsten ignition contacts from chassis 19-EX and 20-EX for examination and replacement. | 3rd Mar 1931 | Box 61b \ 1 scan0145 | |
| Erratic behavior of the battery ignition contact breaker lever at high speeds and requesting an experimental thinner version. | 26th Jun 1931 | Box 61b \ 1 scan0146 | |
| Seizure of the battery ignition contact breaker lever and proposing alternative designs for lubrication. | 29th Sep 1931 | Box 61b \ 1 scan0147 | |
| Request to remove the contact points and condenser from 25-EX and replace them with supplied spares. | 29th Sep 1931 | Box 61b \ 1 scan0148 | |
| Follow-up memo regarding the seizure of a battery ignition contact breaker lever. | 12th Oct 1931 | Box 61b \ 1 scan0149 | |
| The seizure of battery ignition contact levers and arranging a test for a self-lubricated pivot. | 13th Oct 1931 | Box 61b \ 1 scan0150 | |
| Request to obtain two Delco Remy contact breaker levers from Taylor & Briggs or the makers. | 13th Apr 1932 | Box 61b \ 1 scan0151 | |
| Ignition contacts, ballast resistance, and condenser effects on contact life. | 4th Jun 1932 | Box 61b \ 1 scan0152 | |
| Performance of flexible ignition contacts, condenser sizing, and experiments with double breaker distributors. | 6th Jun 1932 | Box 61b \ 1 scan0153 | |
| The misalignment of distributor contact points on car 19-EX. | 8th Jun 1932 | Box 61b \ 1 scan0154 | |
| Endurance test report on battery ignition contacts supplied by Contacts Ltd. | 5th Oct 1932 | Box 61b \ 1 scan0155 | |
| Trial of six Tungsten Contacts from a new supplier, Contacts Limited. | 3rd Nov 1932 | Box 61b \ 1 scan0156 | |
| Two failures of Delco-Remy contact fingers during testing. | 13th Feb 1933 | Box 61b \ 1 scan0157 | |
| Failed Watford contact breaker lever and a request to investigate the material quality with the manufacturer. | 17th Mar 1933 | Box 61b \ 1 scan0158 | |
| Broken Contact Breaker Lever, attaching a letter from the manufacturer, Messrs. North & Sons Ltd. | 24th Mar 1933 | Box 61b \ 1 scan0159 | |
| Letter from supplier North & Sons Ltd regarding a faulty contact breaker lever due to a flaw in the steel. | 23th Mar 1933 | Box 61b \ 1 scan0160 | |
| Letter from North & Sons Ltd. regarding the correction and strengthening of contact finger springs. | 22th Apr 1933 | Box 61b \ 1 scan0161 | |
| Letter to Messrs. North & Sons Ltd. regarding the insufficient loading on four tested levers. | 25th Apr 1933 | Box 61b \ 1 scan0162 | |
| Letter from a contractor, North & Sons Ltd., acknowledging receipt of a letter and remarks regarding the test of 4 levers and spring loading. | 27th Apr 1933 | Box 61b \ 1 scan0163 | |
| Query regarding a seized make and break lever and oily/carbon coated points from a 20/25 HP chassis. | 23th May 1933 | Box 61b \ 1 scan0164 | |
| The failure analysis of a 20/25 Chassis make and break lever from a customer's car. | 23th May 1933 | Box 61b \ 1 scan0165 | |
| The material choice for the pivot pin on the 20/25 HP chassis make & break levers. | 30th May 1933 | Box 61b \ 1 scan0166 | |
| Order for ignition contacts and associated parts from Delco-Remy Co. and North & Sons Ltd. | 31th May 1933 | Box 61b \ 1 scan0167 | |
| Failure of a carbon steel Bentley contact breaker spring from Watford. | 23th Jun 1933 | Box 61b \ 1 scan0168 | |
| Letter from North & Sons, Ltd. concerning the sourcing and preparation of steel springs for Contact Arms. | 24th Jun 1933 | Box 61b \ 1 scan0169 | |
| Letter from North & Sons Ltd. regarding the supply and processing of contact arms and return springs. | 27th Jun 1933 | Box 61b \ 1 scan0170 | |
| Request to order six larger, slightly domed tungsten ignition contacts for an experiment. | 27th Jun 1933 | Box 61b \ 1 scan0171 | |
| Testing of Bensport ignition contact breaker levers. | 4th Jul 1933 | Box 61b \ 1 scan0172 | |
| To Mr. West regarding the suitability for production of contact levers received from Messrs. North & Sons Ltd. | 10th Jul 1933 | Box 61b \ 1 scan0173 | |
| The satisfactory test of Bensport Contact Breaker Levers for drawing DB.346. | 11th Jul 1933 | Box 61b \ 1 scan0174 | |
| The endurance testing of a Watford contact breaker lever. | 15th Jul 1933 | Box 61b \ 1 scan0175 | |
| Request to obtain three modified tungsten contact screws to drawing D.71501. | 14th Sep 1933 | Box 61b \ 1 scan0176 | |
| Internal request to order contact levers from Delco-Remy and Messrs. North & Sons. | 19th Sep 1933 | Box 61b \ 1 scan0177 | |
| Request for analysis of the contact points on attached levers. | 28th Sep 1933 | Box 61b \ 1 scan0178 | |
| Investigation into the seizing of a contact breaker lever on a Bentley chassis due to its Bakelite bush. | 16th Dec 1933 | Box 61b \ 1 scan0179 | |
| Component failures due to insufficient clearance and a recommendation to alter drawing limits. | 16th Dec 1933 | Box 61b \ 1 scan0180 | |
| Modifications to the chassis make and break lever's pin and continental bakelite bush. | 18th Dec 1933 | Box 61b \ 1 scan0181 | |
| The seizing of the contact breaker finger on the 20/25 & 40/50 battery ignition systems. | 20th Dec 1933 | Box 61b \ 1 scan0182 | |
| Instances of seizing contact breaker fingers on 20/25 and 40/50 HP battery ignition systems. | 21th Dec 1933 | Box 61b \ 1 scan0183 | |
| Seizing of contact breaker fingers on 20/25 HP and 40/50 HP battery ignition systems. | 22th Dec 1933 | Box 61b \ 1 scan0184 | |
| Seizing issue with the Bentley Ignition Contact Breaker lever. | 27th Dec 1933 | Box 61b \ 1 scan0185 | |
| The standardisation of Bentley Ignition-Contact Breaker Arms. | 2nd Jan 1934 | Box 61b \ 1 scan0186 | |
| Battery ignition failure caused by a rusting pivot pin on the contact breaker arm. | 2nd Jan 1934 | Box 61b \ 1 scan0187 | |
| Testing alternative methods and materials for the battery ignition contact breaker on a 20/25 HP car. | 19th Jan 1934 | Box 61b \ 1 scan0188 | |
| Issues and potential solutions for lubricating ignition contact breaker cams. | 26th Jan 1934 | Box 61b \ 1 scan0189 | |
| The dispatch of a drawing for a Contact Breaker Cam for the Spectre project. | 15th Feb 1934 | Box 61b \ 1 scan0190 | |
| Production request for one dozen contact lever rubbing blocks to be made from Tufnol bar. | 8th Mar 1934 | Box 61b \ 1 scan0191 | |
| Interim report on endurance tests of Tufnol rubbing blocks and pivot pin bush material for ignition contact breakers. | 19th Mar 1934 | Box 61b \ 1 scan0192 | |
| Standardisation sheet for a chromium-plated pivot pin for the battery ignition contact breaker. | 20th Mar 1934 | Box 61b \ 1 scan0193 | |
| Drawing for a wick lubricator for an ignition contact breaker cam, intended for experimental testing. | 21th Mar 1934 | Box 61b \ 1 scan0194 | |
| Suggesting a modification to the Bentley ignition contact breaker distributor for experimental engines. | 30th Oct 1934 | Box 61b \ 1 scan0195 | |
| Requesting a weight comparison of a new Delco Company make and break lever against the existing 'U' section lever. | 4th Apr 1935 | Box 61b \ 1 scan0196 | |
| Weight comparison between a standard Delco-Remy and a new lightened type of Make & Break lever. | 8th Apr 1935 | Box 61b \ 1 scan0197 | |
| Request to modify a distributor base for testing new Delco-Remy contact breaker levers. | 2nd Jul 1935 | Box 61b \ 1 scan0198 | |
| Test results for a contact breaker lever with a tungsten point welded by a new process after 300 hours of running. | 13th Jan 1936 | Box 61b \ 1 scan0199 | |
| Request to produce three sets of Contact Springs for an electrical cutout as per drawing D.54809. | 12th Mar 1936 | Box 61b \ 1 scan0200 | |
| Booklet on Contact Points issued by Johnson Matthey & Co. | 5th Nov 1936 | Box 61b \ 1 scan0201 | |
| Providing a blueprint for an indicator part and requesting it be put in hand for testing its suitability on distributors for the Phantom III chassis. | 6th Aug 1936 | Box 61b \ 1 scan0202 | |
| Testing an indicator for synchronizing contact breakers, with suggestions for improvements. | 4th Jan 1937 | Box 61b \ 1 scan0203 | |
| Under-tempering of a contact breaker lever spring for Chassis No. 3-AX-49. | 12th Jan 1937 | Box 61b \ 1 scan0204 | |
| Issues with distributor contact breaker lever pivot pins, concluding that electro-tinning is the cause and recommending a switch to Delta metal pins. | 12th Mar 1937 | Box 61b \ 1 scan0205 | |
| Material properties and heat treatment for the Phantom III contact breaker lever pins. | 17th Apr 1937 | Box 61b \ 1 scan0206 | |
| Urgent request for a Phantom III Contact Breaker Finger Spring with a known life for testing due to customer complaints. | 30th Aug 1937 | Box 61b \ 1 scan0207 | |
| Phantom contact breaker spring (D.75146) removed from car 33-EX after testing. | 2nd Sep 1937 | Box 61b \ 1 scan0208 | |
| Laboratory report on the hardness test results for a Phantom contact breaker spring. | 4th Sep 1937 | Box 61b \ 1 scan0209 | |
| Laboratory report on the Vickers hardness testing of a broken contact breaker spring and comparison with other production samples. | 9th Jan 1937 | Box 61b \ 1 scan0210 | |
| Request to assemble half-a-dozen contact breaker fingers for testing, listing the standard parts required. | 2nd Feb 1938 | Box 61b \ 1 scan0211 | |
| Request to Messrs. Johnsonn, Matthey & Co. Ltd. for their booklet on Electrical Contacts and Bi-Metal. | 14th Dec 1938 | Box 61b \ 1 scan0212 | |
| Letter from Johnson Matthey & Co., Ltd. enclosing a publication on 'Electrical Contacts in Precious Metals'. | 16th Dec 1938 | Box 61b \ 1 scan0213 | |
| Request to design a rig for testing contact breakers using a three-phase synchronous motor. | 5th Jul 1939 | Box 61b \ 1 scan0214 | |
| Parts list for a Contact Breaker Test Rig. | 19th Jul 1939 | Box 61b \ 1 scan0215 | |
| Listing parts (Washer, Nut, Distributor Housing) and quantities for production. | 19th Jul 1939 | Box 61b \ 1 scan0216 | |
| Dynamo output curve showing the effect of a two-rate charge scheme for the N.2. series 40/50 HP engine. | 29th May 1931 | Box 61b \ 1 scan0217 | |
| Graph of output speed curves for a dynamo to be fitted to an N.2 series chassis. | 27th May 1931 | Box 61b \ 1 scan0218 | |
| Operating conditions and performance curves for a 40/50 HP dynamo. | 3rd Jun 1931 | Box 61b \ 1 scan0219 | |
| 40/50 Dynamo Output and the rationale for including a specific performance curve. | 5th Jun 1931 | Box 61b \ 1 scan0220 | |
| Requesting an early type 48 coil armature be updated to the standard of the N.2 series chassis. | 8th Jun 1931 | Box 61b \ 1 scan0221 | |
| Accompanying the specification for a running test of a 40/50 HP dynamo. | 1st Jun 1931 | Box 61b \ 1 scan0222 | |
| Specification for a running test of a 40/50 HP Dynamo. | 11th Jun 1931 | Box 61b \ 1 scan0223 | |
| Investigating dynamo performance issues and potential solutions, including tests on series winding, armature saturation, and brush settings. | 24th Jun 1931 | Box 61b \ 1 scan0224 | |
| Experiment involving a series winding circuit for lamps and a dynamo. | 24th Jun 1931 | Box 61b \ 1 scan0225 | |
| Dynamo performance improvements through modifications to field windings and armatures. | 3rd Jul 1931 | Box 61b \ 1 scan0226 | |
| Dynamo performance, concerns of overcharging at high speeds, and modifications to address customer complaints. | 7th Jul 1931 | Box 61b \ 1 scan0227 | |
| Dynamo performance, battery overcharging, and potential control improvements. | 9th Jul 1931 | Box 61b \ 1 scan0228 | |
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