Joined: Jan Thu 01, 1970 1:00 am Posts: 7005 Location: Latham NY
In the Field and Depot Maintenance manual it states the meter is calibrated directly in percent quality of the rated mutual conductance. The actual value of the Gm can be obtained by multiplying the value indicated in % times the rated value of the Gm of the tube in a manual.
Gm= percent quality x rated value of Gm ------------------- 100
You would look up the Gm in a tube manual. I find it very convenient to know the % quality related to 100% being a new tube to make a judgement of the tubes worth. The actual Gm number is not important to me, just the % the tube being tested is what I want to know. This is different from the TV-7 readings which are more vague.
Joined: Oct Sat 20, 2007 3:36 am Posts: 13596 Location: New Hampshire
This is different from the TV-7 readings which are more vague.
Which seems to be the standard of audiophools and some others on Fleabay.
Realize of course that the tube manual Gm is strictly a bogey target and the actual NOS tube can be off 10-20% depending upon production run and manufacturer and it was real bad near the end especially with RCA.