The Turn Of The Century Electrotherapy Museum http://www.electrotherapymuseum.com Super MOT!  4kV, 300 - 500mA Potential Transformer! As my friend Brian put it, you need about 20 microwave oven transformers before you get an actual matching pair. I've come up with a unique solution to having a couple of MOTs friendlier for Tesla Coils. Normally, MOTs have both primary and secondary windings wound on an "E" core with a welded continuous end section that normally contains the mounting bracket.  By grinding the welds with an abrasive wheel, a simple tap with the hammer will release the end piece giving you access to the windings.  In this transformer, I use both primary and secondary windings of one transformer and only the secondary winding from a second transformer.  By centering up things on the core and welding the two sections end-to-end, you can finish the transformer by welding one of the bottom to take advantage of the mounting bracket!  Many thanks to Cip for welding this for me!