[sdiy] A simple 12AX7 vacuum tube tester schematic..

[jpdesroc at oricom.ca]

Hi list,

This request is out of this list topics
but I thought I could get some good advices
from you..

I need a simple schematic for a tester 
of the popular ECC83/12AX7 vacuum tube
used in lots of audio/musical amplifier
these days. I already have 2 tube testers
but because this type of tube draws very little
plate current my testers meter's needle 
doesn't go up very far so readings are
not quite acurates.

All I need is a component list of the best values for
a standard triode tube circuit section that would have:

The VDC supply value for the test schema (ex: 350VDC)
The plate resistor
The cathode resistor (if any needed) to the ground
The grid resistor value (to the ground ?)
The negative bias test voltage (ex: -1.3v)
The uAmp meter value for readings (hooked in series with the plate
resistor)(ex: 0-100uA)
The threshold meter reading value for a GOOD ECC83/12AX7 (ex: 60uAmp
or more is GOOD)

A simple SPDT switch will select what section of the tube is tested.

Thanks
JP