Are the CTC5 HV supplies weak?

[Electronic M]

Yes they are less robust than the 4s and supposedly the 7s (the 7 is the only chassis below 11 I don't currently own) definitely weaker than the 9s.

IIRC the 5s are supposed to run 18KV for HV.
One thing I have found that helps the HV in the CTC-5 is to add an HV reg adjustment pot... The CTC-7 uses the same regulator circuit as the CTC-5 except that the 7 replaces a single fixed resistor in the 5 with a pot and a resistor...I've updated 2 CTC-5s with the 7 style regulator pot and the results have been significant improvements in HV performance in both sets.