Experiment

1.

Set up the EF circuit of Fig. 2.12 using the following values $R_1=10K,~R_2=10K,~R_E=10K, C_1=0.1\mu f,~ C_2=0.1\mu f$.

2.

Theoretically calculate the voltage gain, the input resistance and the output resistance.

3.

Set the waveform generator to 100KHz, and measure the voltage gain.

4.

Place a 1K source resistor between the signal generator and C₁. Now measure the gain as well as the signal voltage at the base. Trade the 1K for a 10K resistor and repeat your measurements. From your measurements determine the input resistance of the circuit.

5.

With the source resistor still in place, place a 10K load resistor at the output from C₂ to ground. Measure the voltage gain. Repeat your measurements with 1K and 500$\Omega$ load resistors. From your measurements, determine the output resistance of the circuit.

6.

Compare your measured results with the theoretical calculations, Does the experiment help describe the utility of the EF amp? To help understand this, consider what would have happened to the signal if the EF were not there, and the 1K load were attached directly from R_S to ground?