MTFCA Forum

I am selling these 1920’s diagnostic meters on eBay. Can anyone tell me how these testers work? A Hoyt Magneto Tester and a KRW Generator Tester. I assume the the engine must be running before the magneto and generator can be tested. Where would the leads be connected to? Is there a plus (+) contact and a negative (-) contact or does it matter? Does anyone have an instruction sheet for these that they can share? I know on the 0 to 20 Generator Testing meter scale it uses Amperes for measuring since it is labeled over the scale, but what measuring unit does the 0 to 50 use on Magneto testing meter scale? Volts? Amps? Thank you. Jim Patrick

The Magneto tester is measuring volts and can be connect to the Magneto post with one lead and a good ground with the other lead.

The current tester measured amperes and has to be connected in series with the wire on the generator cutout that connects to the battery.

If it measures 0, you have to reverse the leads or decide you have a bad cutout or generator.

I also have both meters except both are KR Wilson. Never knew exactly how they worked.