[GarySP]

Hello ODPILOT, I have to concur with the opinions given. To find the basic functionality of a tube, an emission tester like an Eico 625 or a Heathkit tester will get you into the church. If you get to the point where you are looking to get into a particular pew in that church, then you're looking at getting a mutual conductance tester. Regardless what avenue you take, a tester is only as good as its' calibration. Gas and short tests are just as important as output values. Just my two cents worth... Take care, Gary.