oneTesla

I did have some racing arcs on the secondary and lost another set of IGBT's but after some research I landed on this thread:

viewtopic.php?f=15&t=1942

I had been positioning the antenna the farthest the lead would allow but tried it closer, about half the distance. I also reduced coupling by winding the primary on a slightly larger diameter form. Between these two modifications I have been able to run my TinyTesla up to full power with no racing arcs and no more blown IGBT's, so far...