Yes, all of the below.

Sometimes you drill a hole in a small magnet and use a small screw to hold
it to the propeller backing plate. Sometimes you use a strip of reflective
tape on the prop itself. Sometimes you use a pulse from the #1 magneto
lead.

Jim




"Morgans" wrote in message
...

"sleepy6" wrote

That notch causes a much larger timing blip in the signal than any
crank movement will cause. By measureing the time between the timing
blips you can determine the amount of rotation after a timing blip that
you see an up or down crank movement event.

What sort of technology does a proxomity detector use? Magnetics, sonic,
radio waves?
--
Jim in NC