Greg Leyh writes.. > Regarding the breakdown voltage, it seems that the air will only > hold off roughly 800kV/m in this corner of the world using finite > sized electrodes. It's often useful to calibrate your test gap with > a known high voltage rather than rely solely on textbook values. That makes the 17" or so I measured to be around 350kV which is more what I would have expected. I shall revise my 35kV/inch. Malcolm