If this is the ballast resistor it will be attached to the anode of the tube and will likely be a 3 watt or higher power resistor. An open ballast resistor will not allow current to flow through the tube and will cause it to not operate. If it is somewhere else in a circuit, it is likely something else and, not knowing what it does, I can't say what effect it might have.I tested cont from the terminal at the front of the tube to T1 and found no resistance on the first pin with some resistance on the other two pins on the side of T1 closest to the tube. OL from the terminal at the front of the tube to the 3 pins on the side of T1 opposite of the tube. And across the 75k resistor I read OL
Not exactly. I have built variations of that circuit before. The only "ac" is the audio signal. It is connected to T1 low turn side. The HV from HeNe supply is fed in series though high winding side. Audio input causes enough modulation of tube output to be detectable.Are you telling me you've found a way to drive a transformer with DC?