13-11-2016, 02:24 PM
Mutual conductance (gm) is obtained by measuring the change in anode current for a change in grid voltage whilst the anode voltage is held constant ie: change in anode current in milliamps divided by the change in grid voltage in volts, multiply the result by 1,000 to give mA/V (milliamps per volt)
Basically the anode supply needs to come from a low impedance source.
It might be worth reading the first parts of RDH4 Chapter 2, it explains the relationship between the different valve parameters eg: mutual conductance, amplification factor and anode resistance and the method of obtaining them:
http://www.paleoelectronics.com/RDH4/CHAPTR02.PDF
Lawrence.
Basically the anode supply needs to come from a low impedance source.
It might be worth reading the first parts of RDH4 Chapter 2, it explains the relationship between the different valve parameters eg: mutual conductance, amplification factor and anode resistance and the method of obtaining them:
http://www.paleoelectronics.com/RDH4/CHAPTR02.PDF
Lawrence.
