I realize that you need to have the cathode as
the point of reference for your logic to hold water
but everybody uses ground as the point of reference.
To have you use a different point of reference to
get your point believeable should ring some bells.
You don't get to change the point of reference just
to have your circuit theories make sense.
I am talking about a circuit not the tube.
I understand how the tube works, trust me.
The tube works from grid to cathode BUT
the input signal is grid to ground.
Feedback by definition needs to have the output
of the circuit(plate) be fed back to the input(grid).
The input is not on the cathode on a grounded grid.
The cathode signal is a byproduct of the tube's operation.
It is not made by the plate current because the same current
on the plate is the same current through the tube which
is the same current through the cathode resistor.
This current is set by the tubes interaction with
the plate and cathode voltages and/or impedances.
DanL
