When not mounted on a car how can I tell the difference between a battery horn and a magneto horn? Is the difference 1 vs 2 wire mounting studs?
The answer is probably quite obvious but I don't have enough horn knowledge yet.
A magneto horn has an adjusting screw in the middle of the diaphragm. Also, a battery horn has a cover on the back that covers a set of points. Magneto horn have no points.
A battery horn has a large cover on the back, the mag horns do not.
1915 MAGNETO HORN
There's also a variation on the magneto horn that has a tapering cover on the back, versus the small cup style shown above. (Can't find a pic of that one)