Alternator pulses per revolution

[Dino]

I installed a VDO tach/hourmeter in my truck today. I had a lead soldered off of on of the legs from within the alternator when getting it rebuilt. The problem I have now is calibrating the tach to the pulse rate of the alternator.

Does anyone know what is the rate of "pulses per revolution" of these alternators?

I don't have an o'scope to determine this.

I currently have the tach set at 15.0 pulses/rev and am getting an engine speed of 500 rpm at idle and about 4000 floored.

[Diesel Davo]

The Shop Manual seems to have 6 steel fingers on each side of the field winding (thought the picture is small) ... it would make sense since the thing has a 3 phase bridge rectifier to make DC from the AC.

Strange the gas has only 4 and is all totally different animal......