Ways to check 7jp4

[timmy]

I have a bk 440 crt tester and years ago I adapted a 7jp4 plug with the small b&w plug to actually test the 7jp4 and I found that a really good tube would read a 1/4 up on the meter weak was of course lower and can check g1 g2 by the lights on the tester and also clear shorts it all works as if it was any other magnetic deflection tube only the meter is always low so my question is the 7jp4 requires much higher voltage but which pins would be the ones that need the higher voltages. If I had to remove one or two connections from the plug how much voltage would be required since this is the only difference between the 440 and a sencor cr70. Or for that matter does this sound feasible. I do have a 2.5kv source if I could find out where the hv goes.