The MGA With An Attitude

Judson Electronic Magneto This is not at all what I was expecting the first time I saw it. A "magneto" by definition is an ignition coil or generator that is energized by a moving permanent magnet with no outside electrical power required. They are commonly used in small engine applications where no battery is present, like lawn mower, chain saw, leaf blower. The permanent magnet energized magneto is also used almost universally in piston driven aircraft engines because of its inherent reliability, even in the event of electrical system failure. So I was expecting a big distributor with a magnet inside and no external battery wire. Surprise! I suppose the key work here is "electronic", so "electronic magneto" is defining an new type of ignition device that has nothing to do with a real magneto.

This is in fact an early form of high output electronic ignition combining the ignition coil and electronic driver circuit in one package (with no permanent magnet and no moving parts). The idea that it is not a real magneto reduced my enthusiasm considerably, and the more complex electronic bit depressed me even more. With some additional electrical parts that could possibly fail, I don't see how this device could make the car more reliable. Additionally, the instructions contain lots of notes about keeping the high tension wires in good condition, because the "high pressure" spark can easily cause break-down of the insulation with older HT wires. I don't know what else to say about it, except apparently it was all the rage back in day, and maybe putting another brand name sticker on your car was a big deal.

Judson Electronic Magneto booklet
Click for 580-KB PDF file, including installation instructions.

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