"Ian Thompson-Bell" wrote in message
...
I have being playing around with plate characteristics graphs, looking at
how basic parameters (gm,rp and mu) vary with operating point. The most
frustrating thing about this is that the published curves all extend to
rather large plate currents and voltages. For my preamp I am working at
plate currents of less than 5mA and the curves here are rather cramped. Is
there any source of curves that are expanded for the lower plate current
region?

Cheers

Ian

Hi Ian:

If you give me the range of plate currents and voltages, I can plot you a
set of curves on my tracer and email you a digital camera photo of same. For
example, if you tell me that the maximum y-axis current you want is 5mA and
the x-axis voltage (Vak) is to be 300 volts, I can plot you a set of 11
curves, including Vgk=0V. I can set the grid volts per step to anything
you'd like within reason.

Just let me know the values you want and I'll give it a try. Please also
let me know:

1) Do you want the screen grid connected through 100 ohms (or other value)
to the plate, or just a direct connection?
2) I can connect the suppressor grid anywhere you want. Either to the plate
or to cathode are the obvious choices. Where would you like it or do you
want curves for both connections?

All the best : Doug Bannard, P.Eng. )