A common collector amplifier without a bypass capacitor has RE = 1.5 kohms and RC = 2.1 k ohms and r'e = 17 ohms. The voltage gain is approximately

Voltage gain, Av = RC / (RE1 + r'e)

Thank you for your help

To determine the voltage gain of a common collector amplifier without a bypass capacitor, we need to use the formula:

Av = (-gm * RC) / (1 + gm * RE)

where Av is the voltage gain, gm is the transconductance, RC is the collector resistor, and RE is the emitter resistor.

To calculate the transconductance (gm), we can use the formula:

gm = 1 / r'e

Given that r'e = 17 ohms, we can calculate the transconductance:

gm = 1 / 17 ohms

Next, we substitute the values into the voltage gain formula:

Av = (-gm * RC) / (1 + gm * RE)

Av = (-1 / 17 ohms * 2.1 k ohms) / (1 + 1 / 17 ohms * 1.5 k ohms)

Simplifying the expression,

Av = (-2.1 / 17) / (1 + 1.5 / 17)

Av = -0.123

Therefore, the voltage gain of the common collector amplifier without a bypass capacitor is approximately -0.123.