Its me again.....
First off I'd like to thank John M. & Mark Q. For my last posting.

I don't have a tube tester or know anyone that does.. But I do have a very good Fluke Digital multi meter, and a old (60's or so) Snap On 12 function analog meter can is there a way to use throes to test a tubes? If so How?

Hi,
There is an indirect way withthe tools you do have to get an approximate idea of tube quality. If you have the tube specs available, you can do a few things to get a realistic idea of tube condition. If you measure the voltages at each pin, you can establish a good idea of what voltages are present at the tube. If you are checking a 6C4 (it is a triode, but makes illustration easier.) If you measure the voltage between the cathode and the plate, you have a measure of the voltage drop across the tube. If the circuit can operated without that tube in place, you can measure from the same points and usually find a different voltage between plate and cathode. The closer those two measurements are, the less conductivity within the tube (assuming the circuit is otherwise fine), which means the tube emissions are less. A more direct manner is to disconnect the cathode connection, and put the milliameter in series with the cathode, and it's circuitry to ground. That measurement should be compared to dissipation "Plate current", and citing the 6C4 above, in an audio circuit, 10.5 to 11.8 milliamps is average.

You could also use Ohm's law with the voltages cited initially, and it will give you a value to work with also, as the tube will have a resistance of it's own the circuit, but there are a lot of areas where errors can be introduced because your tube can average about 6-7KOhms, and in some circuits, that is a small amount in relation to the rest of the circuit. Once you move into the IF and RF stages, you have to address frequency issues, reactance, capacitive paths to ground, inductive resistance, as well as your usuall DC parameters.

:Its me again.....
:First off I'd like to thank John M. & Mark Q. For my last posting.
:
:I don't have a tube tester or know anyone that does.. But I do have a very good Fluke Digital multi meter, and a old (60's or so) Snap On 12 function analog meter can is there a way to use throes to test a tubes? If so How?