The Turn Of The Century Electrotherapy Museum http://www.electrotherapymuseum.com Unpotting a Neon Transformer It has been said before that most neon transformer failures relate to the tar instead of the actual windings.  (Carbon tracks that form inside - especially when used to power Tesla Coils!) So I took the hammer and chisel and some spirits and unpotted a 9kV 60mA and a 5kV 120mA... 9kV 60mA 5kV 120mA The tools! Added one output wire to 9kV 60mA Needed to redo both output wires on the 5kV 120mA Side by side for comparison - left 9kV 60mA, right 5kV 120mA A beautiful Io Dreaming of mice and squirrels!