Your HV may not be regulating. Dark pix puts less load ( beam current)
on the HV so if its not regulating it can go up.
Usually the pix will also bloom ( expand & contract ) as you run
the brightness up & down.
Origional G-13 did have 2 h outs. When the flyback went it
came as a kit with lots of mods for the different runs.
We had an old goat that did them all but it took him two mornings.
Maybe cause he was in the can nipping vodka a lot.....
73 Zeno
