I did this video to show how we rate the output of a generator for a someone wanting to see what testing we did. We're using an XT500 one but the split AC/DC generator is used on 99% of vintage enduro bikes of the 1970s.

We often get requests to make generators on these bikes more powerful. However just simply adding a few more turn of copper wire in a random fashion often makes the output worse! We've taken a lot of time trailing different winding configurations and trying different techniques to get more power. You can imagine how long it takes to test a new wind - having to wind it, mount it to the test rig and then run ing fully (the full testing often takes nearly an hour). If its wrong or un-stable you have to start again. Fortunately we now a have a few rules we can apply to get us near if not bang on an improved output or 12 volts from a previously 6 volt winding.