[Amps] Changing class of operation with BIAS

[Rob Atkinson]

>So you are not changing the bias, even though resting current has changed, but
>you are changing the conduction angle and thus the class of operation (triode).
>Question: How can you change the class of operation and conduction angle with
>no change to bias. I apologize, but I am confused.

You got a lot of answers, a lot of words, some or all correct, but not
what I think you were looking for.

A tube (triode for example) is like a ball valve in a water pipe.  You
can change the flow by cutting it almost off with the valve, but you
can increase the flow by increasing the pressure into it or the
suction pulling water out of it.  A tube (called a "valve" in Britain
not coincidentally) has all kinds of ways of changing its behavior
besides bias.  Increasing the plate v. alone is like increasing the
suction on the water coming out of the valve.  Higher positive v.
exerts an even stronger attractive force on the negatively charged
electrons boiling off the cathode, in spite of the grid v.   This
pulls more of them to the anode past the grid and the anode to cathode
current increases.

73
Rob
K5UJ