Laplace - no technical arguments, but polemic answers only (and I wonder- Why?).
Therefore, I reply to one sentence only:
Laplace - in post#66 your wrote:
"
Emitter degeneration is absolutely necessary to reduce the circuit's sensitivity to variations in transistor beta."
In my post#67 I have asked you to explain this statement (because I think it was wrong).
Now I have to recognize that you are not able or not willng to explain your own claims - instead you are referring to a page containing questionable "explanations". (By the way, as you probably know - it is not a problem to find pages with wrong descriptions/explanations in the internet).
So - I will explain it to you and I wonder if this will be a new information for you (to be found also in all reputable textbooks):
(1) It is the task of the emitter degeneration resistor Re to reduce the sensitivity of the required
emitter current Ie to uncertainties of the
base-emitter voltage Vbe=Vb-Ve (initial uncertainties and temperatur influence, temp-co: d(Vbe)/dVth=-2mV/K).
It is easy to verify this effect by looking at the required base voltage
Vb=Vbe+Ve=0.7V+Ie*Re.
As you can see, the influence of the assumed Vbe value on the required DC base voltage Vb is drastically reduced if Ve=Ie*Re>>0.7V.
(2) Because the voltage Ve=Ie*Re causes a
negative voltage feedback effect we require that the DC base voltage Vb is as "stiff" as possible (preferrably independent on the voltage divider load current which is the base current Ib).
For this purpose it is common practice to design the base voltage divider (for providing Vb) with relatively small resistors allowing a DC current of app. (6...12)*Ib. In this case, the load current Ib (app. 10% of the divider current only) plays a
minor role only for establishing the desired "stiff" base voltage Vb.
(3) Summary: The emitter resistor Re provides negative feedback thereby reducing the effect of Vbe uncertainties and the choice of a low-resistive base circuitry reduces the influence of base current uncertainties upon the base voltage Vb. Both principles are effective only because the BJT is a voltage controlled device : Ic=f(Vbe).
Anything wrong?
_________________________
Laplace - I have one final request to you.
You wrote:
"So now we can add this to the list of your misconceptions".
In order to concentrate our discussion really on the critical points of disagreement I kindly ask you to show me the list of my misconceptions (if it is not too long). Thank you.
LvW