VHO Ballast question

[Rikko]

Interesting.. So where does the difference between NO/HO and VHO come in? On my WH7 I ran a NO and a HO T5 on different leads. The HO (39W) was definitely running HO (well, visually it was an enormous deal brighter - I didn't hook up any meters). Suppose I stepped it down to smaller bulbs so that a VHO bulb were 40W (say it's a theoretical 12" VHO tube). (I do this only so we have a single output lead for my Workhorse ballast for any bulb type). I connect my 12" NO = light. I connect my 12" HO = light. Now I connect my 12" VHO = how much light? Will it run at HO but not VHO? Is the electronic ballast able to dump out a variable amount of current for each bulb type, but just not enough for a VHO?
<even more confused than before>