Brief note on the engine : 72 model complete with 2 wire Sensor ( Hall effect ? ) and Distributor rotor sensor ( metal notched ring ). Only came this way from factory.

I installed a 6AL c/w blaster pack and 8 ohm resistor to replace factory unit. Shorted the magnetic pickups from MSD and we got plenty of juice from the coil.

Problem I am having is that the MSD is not reading the factory sensor output.

I tested the sensor and it read 5.2 ohms across ( and also on the 2 wires ). Its within factory spec of 4 - 6 ohms.

When I manually turn the crank and the distributor rotor passes across the face of the sensor, I get a reading of 5.1 ohms. This seems to be consistent.

Plug the wires into the MSD pickups and nothing.

After reading info on Hall effect - I was told that the johnson was producing a square wave ( digital ) and the MSD needs to read a sine wave ( analog ) in order to energize the coil.

Some confusion since the 72 predates MSD and MSD products are used on motors of that era. How is the johnson " digital ".

Regardless, if it is digital - is there a conversion that takes that reading and converts ( inverts ) that Halo effect to something the MSD can use.

I can go to points but don't really want to if a solution exists. its a pretty good setup with everything fitting perfectly.

Any clarification would be helpful. If I have posted this in the wrong place, my apologies and move the thread where it belongs. Apologies for description , I am a newbie but intrigued.