[ARC5] VR Tubes

[Robert Eleazer]

"For one thing, VR-tubes must be able to have some input from light to 
"encourage" the formation of the internal "plasma""

Then how does the one in my RT-7/APN-1 work given that it is sealed inside a case that has only a few air holes in the back?

Admittedly when I fired it up in order to see that big black line on TV channel 14 I always did it with the case off so I could see that neat blue glow.

Wayne