[mikethedruid]

Mike, do you remember, when we were kids, they used to sell these chepie "test them yourself" tube testers that basically only checked the filament for continuity? They had a neon bulb and resistor, so the current they passed through any tube wouldn't blow the filament, and if the filament was good the bulb would light up. Beyond that basic test they were worthless, couldn't tell you if the tube was weak or not, so if it was on its last legs, and could never function properly, it still gave a good reading.