65 might have been right depeding on what ballast was being suggested;the old bulky tar based ballast are pretty heavy;especially the commercial ones used in workshops & what not;we tried to do a DIY VHO set up, but was unable to get it to work at all;the balast was bought new from a local electric supply;it was very heavy; I'd stay away from it if that is the case;even if could save as much as 50% compared to other VHO systems; tar ones old tech, bulky, give off a lot of heat