Mercury arc rectifier

[Mike Watterson]

Thanks, Jeffery. A couple of interesting links and Hertha sounds amazing.

Plasma speaker designs ionize ambient air which contains the gases nitrogen and oxygen. In an intense electrical field these gases can produce reactive by-products, and in closed rooms these can reach a hazardous level. The two predominant gases produced are ozone and nitrogen dioxide.

https://en.wikipedia.org/wiki/Plasma_speaker
Perhaps if I assemble the plasma speaker it should only be for short demos.

I've noticed that there is some RFI from fluorescent tubes even with passive choke ballasts. Maybe you can check out the MAR with a pocket AM radio?