Info/docs on tube tester?

Yes, better than Heathkits, but these days even the high quality stuff is cheap and available (HP, Tektronix, Boonton, General-Radio, etc.). Of course, the one place where you will have to spend money on old test equipment _is_ that of tube testers, mostly due to the audiophiles. If you can get a good old Hickok for less than $150, you should jump on it. The name came about by all of the smartass hams at the hamfests that would watch some of us lug 90 pound tube radios back to our cars ("hey, where did you get the boatanchor!"), while they had whole Kenwood stations that would fit in a fairly small box. Of course, they would really start laughing when we would have to go back to get the 40 pound power supplies. Anyway, I really wonder how good most (all?) tube testers would be for digital logic applications. All of the good testers I can think of do a fine job on emmision, shorts, and gas, but the gm test generally is fairly dumb - a steady 60 Hz (sometimes 1 kHz) fed into the grid, and look at the output. That is exactly what logic circuits do not do. The Tek tube curve tracer (model 577 or 565 - help! I can not remember) would be very good, but you would have to sell your Imsai and Altair to pay for one. William Donzelli william(a)ans.net