Vacuum Tube Tesla Coil Schematic VTTC

Above is a schematic for an easily tuned vacuum tube tesla coil. To build the tickler/feedback add a few more turns to the base of the secondary and ground the point they join. The base of the secondary now connects to the grids.

Below is a video of the setup and operation. Power is about 650W.

Update: I achieved 30cm arcs at 1200W with this unit. Arcing to ground will cause serious over voltage on the primary be sure to add a spark gap. Also added a toroid with 10 turns of 5kv wire between the tank circuit and hv out from doubler for emi filtering.