Do a search on Microwave Oven Transformers in RCM. A typical MWO
transformer is good for about 1000 watts. The secondary is fairly easy
to remove and a new secondary can be wound on. You get about one volt
per turn so you don't have to have many turns.

I can find Mircowave Ovens for two or three dollars at the St. Vincent
de Paul that are guaranteed to be defective. I have only purchased
two, but both of those had good transformers.


Dan