James: "What is the dog house hole? Is it the slot in the middle of the PSU panel where the HV lead
The HV section has a metal cover (doghouse) with a 3/8" hole where HV U;tpr 21 kV connector exists from HV multiplier.
Adding insulation is useless.
Just be sure the cable and Alden connectrs are clean and ry.
Ozone: even0. 1 PPM is easily penetreating smell
No tube needed.
Jon
Jean-Paul