Spectral Demonstration Lamp

This is a well-made demonstration tube. It was sent to me by Peter Jameson; he sells some nice short spectral tube for neon and mercury in this format on eBay. This mercury tube has a section fluorescent coated so works as a nice demo of how fluorescent tubes work. It’s a cold-cathode tube and can run from a small CCFL driver or as I have here a small neon sign transformer with no more than 30mA output. This particular neon transformer, just visible, is an old-school auto-leak version salvaged from a obstruction light. I have also inserted the spectral lines from either side of the tube to show the addition of red from the fluorescent coating.