electrodeless tubes

These are a few sealed off tubes I made a few years ago. They contain various gases and some additives. (Argon, Neon, air, iodine, fluorescent powder). They are all being lit with a high voltage high frequency AC supply I have been building and experimenting with. The transformer is made with the parts of taken from 2 old TV line output transformers. All the discharges are capacitively couples from the two metal tape strips running underneath. The metal tape strips around the tubes themselves are only to protect the tubes from arcs to the glass which quickly puncture them. I particularly like how they all can be driven at once despite being different pressures and gasses.