> I also have an assortment of T1A sized tubes (1.125" tall by .360 dia glass) > most of them are 5899 and 5636 RF pentodes. Those are not T1 bulbs - they are T3 bulbs - standard subminis. T1s are like NE-2 sized. Sylvania managed to cram two triodes into a T1, but they never left the lab. William Donzelli aw288 at osfn.org