I think the Sylvania ones start out F0 13. Does anyone know what the correct nomenclature is and what the wattage is. Phillips lamps  say  F15T8D  HF on theirs. What ballast? I have one that will operate 17 through 32 watt lamps. Can I use this on a 14 watt bulb with only slight overdrive? Will it run a T12 20 watt one acceptably?  Tests could begin.....