Small Vacuum Tube Tesla Coil 2

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This tube tesla coil was built inside a CPU power supply unit. It was first built on a workbench using components and jumpers for connections. The tube used is a 4X150 transmitting tube that used forced air cooling. An old oscilloscope transformer was used for the power supply, providing about 1kV for high voltage and 6.3VAC for the filament supply. I experimented and played around with the circuit and came to this strange design that has no capacitors. Below is the schematic diagram.

Parts List
V1 - 4X150
D1 - High voltage diode
R1 - 20M ohms, 1W
R2 - 5 ohms, ~15W
L1 - 25 turns 23 gauge above L2 on 4-inch PVC pipe
L2 - 20 turns 24 gauge below L1 on 4-inch PVC pipe
L3 - About 285 turns 24 gauge on 2-inch PVC pipe - 6 inches from bottom to top
T1 - 1kV, 6.3V power transformer (old oscilloscope transformer)

The discharge length generated by this VTTC is about a half inch long.

The original setup on a workbench

Half inch long streamers in the air

Light bulb used as a plasma globe