For my 45" with magneto ignition I want to install an electronic analog rev counter.
The only signal source I can think of on my bike is the spark plug wire (there's no battery, timer or coil). The signal wire is then wrapped several times around the spark plug wire (so called inductive signal).
I have only seen digital rev counters making use of such inductive input (see picture 1). But I want an analog rev counter like the MMB in picture 2. Also want to avoid a mechanical driven tacho.
So... is it possible to convert the inductive signal to the signal the MMB electronic tacho can use? Or is there any another trick I can use?