> Don, > Well gee, just because you put a 100th/tl tube in does not mean > you have to strap it. > You CAN run tubes well under their ratings... > > What does an 808 look like? > I will check for some when I get home. > > if you was to ask me, running a 100th/tl tube well under ratings > is a great way to go.
Sure it is. the tube will last lots longer, if it's not being run near the hairy edge of it's rated capacity. I have a pair of 250TH's - I used to run 2000v @ 300+mA - can't do that no more. Grab the vari-ac knob and reduce the B+ until we're dropped down around the 500w DC Input level, and modulate it 100%, and pray to the Mightiest Keeper of Electrons that I've got asymetrical audio, and that the peaks are better than 3 or 4 to 1. Point is, at 250w of plate dissipation, each - at anything less than 500w being drawn in the final, those tubes don't even know they're on. Before we get deep into "preserving Tube life", Don/K4KYV wrote something a while back, about the property amount of voltage to run on a tube. Some of us (back then) thought that by reducing the voltage of the filaments to a point just before the tube started to lose emission would help further prolong the life of those old fire-bottles... but Don found evidence to the contrary... and I simply can -not- remember -exactly- why that was. Don Chester - Why shouldn't filament voltages be reduced on vacuum tubes, to presumably preserve the life of the tube? 73 = Best Regards, -=Geoff/W5OMR=-
