Rev-counter upgrades ( Smiths / UK Jaeger*only )  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 can be upgraded to work with  Electronic ignition
Whilst retaining the ‘RETRO-LOOK’ i.e. 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 if fitting electronic ignition later )

The second popular upgrade is from Smiths type RV ( camshaft generator ) E-type series1 etc  to
either RVI v1 / RVI v2 if using points ignition or RVC for electronic ignition ( will also work with points ignition )

Smiths type RVI v1 to RVI v2... reduces / eliminates  loss of calibration / over-reading when hot !

Smiths type RN (cable driven) units can be upgraded to  RVC ( clockwise direction only ) eg. Triumph TR range

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

Note: all upgrades to type RVC are for NEGATIVE EARTH systems only ( i.e. NEGATIVE  pulse )
( A connecting diagram will be included with all upgrades )         *UK Jaeger was made by Smiths