Thread by @TubeTimeUS

i'm testing more vacuum tubes this afternoon. as you do...

don't use soap or water to clean a tube, the numbers will come right off. instead I just gently wipe it with a cloth.

first step is to find the tube in the little roll chart built into the unit.

find the right socket.

then set the filament, grid, and plate controls.

then set the control levers. the ten levers on the left set the pinout, the ones on the right set the plate voltage range and the meter sensitivity

turn up the AC voltage and push the line button. adjust it until the meter is straight up and down.

first check is for leakage. push the buttons listed on the chart and make sure the reading is 0. underlined numbers have inverted meter readings.

then push the buttons listed under 'merit' and pull down the merit switch to take a reading. this tube looks ok.

since this tube has multiple devices inside we have to follow the directions for each of the three entries. and then we are done!