The mutual conductance (micromhos) reading is the minimum reading for a "good" tube. A reading less than that indicates a "weak" tube.
Note that to read micromhos directly you do NOT set the shunt dial to what is listed in the chart. The chart setting is for reading on the "good/replace" scale on the meter. To read on the micromhos scale on the meter, you set the shunt dial to one of the three red dots that are on it, corresponding to which of the three micromhos scales you want to use.
You'll find the following video of interest, although it looks like he is using the tester incorrectly relative to what I said in the previous paragraph about the shunt setting:
http://www.youtube.com/watch?v=OVMnKIM4LEc
Also, note that the 6000A does not provide sockets for testing of early tube types:
http://www.vacuumtubes.com/6000.html
Regards,
-- Al
Note that to read micromhos directly you do NOT set the shunt dial to what is listed in the chart. The chart setting is for reading on the "good/replace" scale on the meter. To read on the micromhos scale on the meter, you set the shunt dial to one of the three red dots that are on it, corresponding to which of the three micromhos scales you want to use.
You'll find the following video of interest, although it looks like he is using the tester incorrectly relative to what I said in the previous paragraph about the shunt setting:
http://www.youtube.com/watch?v=OVMnKIM4LEc
Also, note that the 6000A does not provide sockets for testing of early tube types:
http://www.vacuumtubes.com/6000.html
Regards,
-- Al