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Fixed price repairs are based on the assumption that unit/s received
‘original & complete’... a surcharge may be applied to cover
missing  parts etc...  If in doubt send in the unit for inspection
Good  luck with your project’...  Enjoy your classic motoring...
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Mileage correction
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Rev counters
Jaguar XK 120 ( 1948 / 54 )
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JDO Instruments

Classic Car Instrument Repairs ( Est 1963 )
Fixed price repairs for most British & European Classic Car Instruments
48hr service  available... Why pay more & wait longer ! No UK vat
Tele:   01535 603570 / Mobile: 07872 071512
Please check the  FAQ’s page  BEFORE ringing / texting / emailing

Rev-counter upgrades ( Smiths / UK Jaeger* )  Surcharge applies...
Early electronic rev-counters were designed for use with either a ‘Camshaft generator’  ( type RV )
or ‘Points based ignition systems’ ( type RVI )  If you intend fitting Electronic ignition ( including 123 etc )
most early Smiths / Jaeger Rev-counters ( including ‘cable driven units ) can be upgraded to work with
Points OR
Electronic ignition whilst retaining the ‘RETRO-LOOK’ ie. once re-fitted only you will know of the upgrade !

The most popular upgrade is from Smiths type RVI v1 /  RVI v2  current loop system ( points ignition )
to RVC earth pulse system which will work with electronic ignition ( or points ignition if fitting electronic ignition later )

The second popular upgrade is from Smiths type RV ( camshaft generator ) E-type Mk1 / XK150 /  early Aston Martin etc  
to either RVI v1 / RVI v2 if using points ignition or RVC for electronic ignition ( which will also work with points ignition )

Smiths type RVI v1 to RVI v2... reduces / eliminates  loss of calibration  ( common fault with RVI v1 ) units
Smiths type RN ( cable driven ) units can be upgraded to  to either RVI OR  RVC e.g. Triumph TR range / Early XK etc

Smiths RVC units can be re-calibrated to suit ‘wasted spark ( DIS ) ignition systems’ ( e.g. no distributor )

Upgrades to type RVC can be  NEGATIVE OR POSITIVE EARTH ( please confirm polarity required on your order )

Many other makes ie. VDO / AC / VEGLIA / American etc can be ‘upgraded’ but please ring 1st before sending

Please specify number of CYLINDERS / TYPE OF IGNITION & EARTH POLARITY with your order

( A connecting diagram will be included with all upgrades )         *UK Jaeger was made by Smiths
Up Triumph TR6 over Triumph Stag
Connecting diagrams