Hey-Hey!!!, Hi Mark, thanks for the experience and Math. I think that a suitable TX would be a PP plates to 500R. These seem to be in low demand. Plates to voice coils, that's another story... A 3:1 PP:PP step down ought to do. PP 2A3 is exactly what I had in mind. 5k:500 is 3.33:1 and getting both CT ought to be fairly easy. Probably about what shipping from OZ would be. Now if I could figure a good way to do just a bit of NFB, I'd go and order some bits. regards, Douglas