Common emitter amplifier gain with load resistor?
At 0.3 milliamp collector current, the derivative of (Vbe / Iout)
which I personally label 'reac', is about 80 ohms.

Simply divide that into the collector load resistance, which is the parallel combination of the two 10 KOhm in parallel

5,000 / 80 = 63X

By the way, the derivative of (Vbe / Iout) is 1/gm.

Thus my 'reac' is just 1/gm.

At 1milliAmp Ic, the gm is 1/26 ohms and the reac is 26 ohms.

If you have an emitter resistance that is not bypassed, as in this schematic below, simply add the reac to the Re, then divide into the collector load.







simulate this circuit &ndash; Schematic created using CircuitLab