03-11-2016, 07:13 PM
Mark wrote "What I'd really like to see is a graph of gm verses Ia"
1st graph:
http://www.r-type.org/pdfs/el84.pdf
Just a general note: To determine mutual conductance from a set of anode characteristics.....Draw a vertical line at the voltage of interest so that it intersects two grid voltage curves, that represents a change in grid voltage for a constant anode voltage, draw a line from each intercept point across to the anode current, that represents the change in anode current for the change in grid voltage.
Subtract the lower grid voltage from the higher grid voltage, subtract the lower anode current from the higher anode current, divide the resultant change in anode current (in milliamps) by the resultant change in grid voltage to obtain mA/V.
Lawrence.
1st graph:
http://www.r-type.org/pdfs/el84.pdf
Just a general note: To determine mutual conductance from a set of anode characteristics.....Draw a vertical line at the voltage of interest so that it intersects two grid voltage curves, that represents a change in grid voltage for a constant anode voltage, draw a line from each intercept point across to the anode current, that represents the change in anode current for the change in grid voltage.
Subtract the lower grid voltage from the higher grid voltage, subtract the lower anode current from the higher anode current, divide the resultant change in anode current (in milliamps) by the resultant change in grid voltage to obtain mA/V.
Lawrence.
