I have been fighting to get a stable Rotor Tach display since I started flying. I have used at least 4 certified rator tach generators. I think they must be designed for a mechanical display that dampens the signal through hysterisis or friction. With my MGL Odyssed these do not exist.
Shown is my solution. This is known as a Proximity Sensor. I don't have the part# handy but if anyone is interested I can supply it. This thing was CHEAP. I think it was $30 including the cable with preinstalled connector. the theory is that you swing a piece of iron past the end and it generates a signal. You need to swing the iron past the end of it not just under it.
I am currently using only one chunk of steel but will add another for balancing purposes one I get a chance. No moving parts. I do need to make a more elegant mount now that I know it works.
