I have a tachometer either from a boat or aircraft, dated June of 1947. The info tag riveted on says "Indicator- Electric Tachometer", made by GE with a complete part number of 8 DJ13 AFF sub 28. (I had to ad a space between the 8 and D to keep a smiley away)
I have found some similar ones, but no information on operation aside from references to a tach generator.
I would like to know how to wire this unit, and drive it, to see if I can use it in a project. If anyone has any info on this I would appreciate it.