[Amps] HV transformer and Variac

[Fuqua, Bill L]

  I have found that old variacs are good for easily winding my own filament transformers.
Larger ones are about 2 turns per volt and if you have a damaged one, just remove the 
hardware, if there are a few burnt turns just cut and unwind them and reconnect the
good parts. I usually then wound some high temp insulating tape around the core and
wind my secondary over that. 
  If you space the secondary some distance off the primary you will have a low
capacitance transformer to provide some isolation for grounded grid operation in some
cases if you need really high voltage isolation.
73
Bill wa4lav