Quote:
Originally Posted by AmadeusMozart
In order to measure the mu we need to have a constant current source. At the moment there is a current limiter in the plate supply chain however if we make this adjustable then we get constant current source.
We then measure AC current instead of AC voltage and we've changed the setup into a mu meter.
|
I believe that the RAT-Tester that Steve Bench designed a long time ago uses a mosfet transistor in the cathode circuit to perform this measurement, take a look at the circuit diagram here:
http://www.jacmusic.com/techcorner/S...MMU/gmmu_1.gif (the texts can be found either here:
http://www.jacmusic.com/techcorner/S...h101/#TubeTest or here:
http://triodeel.com/tester.htm).
It should be possible to incorporate this design in the Sussex Valve Tester since they are similar in design otherwise (the Sussex almost looks like a copy of the RAT-Tester to me).
/Martin