Westinghouse H840CK15

[benman94]

The ability of the RF from the Tesla coil to excite the gasses in a sealed low pressure tube is inversely proportional the pressure of the gasses inside the tube, over a fairly wide range of pressures. At about 3 torr, the pressure inside of the typical CFL, the Tesla coil was capable of exciting the gasses. Pressures too high will not allow the excitation of the gasses to be visible. On the opposite end of things, a pressure too low won't allow one to observe excitation of the gas from a Tesla coil either.

Once we get below about 10^-3 torr, the excitation of the gasses from the Tesla coil should no longer be visible. A CRT with a pressure above about 10^-4 torr is useless and will start arcing. A tube at 10^-6 to 10^-9 is ideal.

Given what I've observed thus far, I can safely conclude that the tube must be at a pressure no greater than 10^-3 torr. Even a Tesla coil isn't as fool proof as I had thought... Nick is right, the only good test is a working chassis.