I would not like to put a Hall Effect sensor near a stock charging rotor or any other magnetic item separate to the sensor itself.
I was thinking off the shelf Boyer, Pazon (that has a Boyer connection ?) programmable Tri Spark, PowerArc < ? , there is even a Wassell ignition (iirc)
All pretty much proven reliable it seems. (with a decent loom and grounds)
Maybe it is or is like the white PR on the Norman White website.
I am pretty sure all of this was covered further up in the thread, which explains exactly what is on this bike and covers other installations.
The Thruxton race shop were early adopters of the Lucas Rita Ignition system, which is what is fitted to that PR. And which is at least two steps removed to the ignition on the PR that is the subject of this thread.
What you are looking at is the large pickup that they had to modify the timing cover for. Lucas then developed a much smaller pick up which mounted entirely within the ignition cover.
I didn't see anyone else using one of these cutaway timing covers in the '70s, except Tony Smith, who sold one to me...
I do think Gus Kuhn may have had a couple. The one I had had come from the race shop and had the advance circuit linked out and only ran full advanced.
Why would you want a crank pickup? Well I had a Maney one and as soon as you strobe the ignition the additional stability of the timing is striking. No chain flopping around.
Why didn't Norton do it then?, I hear you ask. Well, they simply ran out of time! The crank that was in the bike I fitted the ex Thruxton ignition to came from the Experimental shop. It was a MkIII crank and had been used in a rig that was testing 'crank triggered ignition'. I was able to buy an engine as a kit of parts from the guy just after he was made redundant in 1975....as Norton were closing.
Several current racers use the crank triggered ignition in several designs, and all quite successfully.
Bruno Perlinski fits a self generating type to most of the bikes he builds.