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So i have to make a circuit for my university, and it has to be made in electronics workbench. I tried to make a class A amp after this schematic:enter image description here

And made this in EWB: enter image description here

My problem is that my circuit weakens the signal rather than amplifies it (here is a picture of the oscilloscope):enter image description here

The first one is the input (channel B) the second one is the output (channel A)

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It appears that your signal frequency is 20 Hz. This is too low for the sizes of the input and output capacitors. The input capacitor and the two base bias resistors form a high-pass filter of approximately 480 Hz. The transistor's input impedance changes the actual corner frequency, but it still is way above 20 hZ.

A similar situation is happening at the output, with the circuit's output impedance and the output coupling capacitor forming another high-pass filter.

As a simple test to see if this is contributing to what you are seeing, raise the test frequency to 1000 Hz.

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  • \$\begingroup\$ Thanks! That kind of worked the signal now is at least similar to the input ill change the values around until i get what i want. \$\endgroup\$ Jan 28 '20 at 4:28

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