Closure,
I have essentially finished my Changfa type 15kw gen set. The ST head had lost residual magnetism, but by running it under load with an external field power source, the magnetism has returned.
I think I will run this gen set with an external field excitation anyway, since the quality of the output is much better this way. I'm using a Chinee variac, thru an Indian bridge rectifier, thru Japanese filter caps. The output is very clean, and someday I will put it to the ultimate test and try to run a microwave oven. I've managed to produce 48 amps max @ 220V and this is close enough to the max power that I'm happy with it.
My attention is now turned to my listeroid 20-2, which is re-assembled and will be ready to run soon. Will continue to update on my Lovson 20-2 thread.
Zeke