have had a fixture in my bathroom that never was as bright as i expect for a f40t12.even taking into account it was a c50.well its buzzing got to me and i got a hold of some robertson electronic units from a friend who used to work for them.made for a 18w cfl but he stated that it was good for anything upto a f40t12.only difference was the label for some sort of regulatory compliance.
rated for cf18pl,cf18dl,and f20t12.
so 300+- ma.
its brighter than the old one rated for the 40t12!
runs room temp too.the old one had alligatored the paint it got so hot.dated 0791.
fixture is all chrome and glass from the 40's.so well worth a ballast and repainting the reflector.

The RL-140-TP is a residential use only ballast rated for 63% output, or 91% with 25W 48" T12 "utility shop lite" lamp.  That's roughly the same output you'll get from running F40T12s on a F32T8 ballast.