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Measure the equivalent resistance in a simulator
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bonzer:
Hello! Please help me to understand how to properly measure in PSPICE the impedance (real) of this amplifier seen from these points.

As you see I assigned particular values for the capacitors, 1mF for those that should behave like a short circuit and 1pF the open circuits (because want it in passband).

I tried different ways like: putting a current source dc or ac of small value 0.1 or 0.01 and measure the voltage at it's points but it gives me different values of resistance that change depending on the case. But this way the polarization of the transistors is verified at least (Vbe =0.7V).

When trying to apply thevenin instead, I let it run with the power supply only and then measure between those points the voltage and after that I put a short circuit there to measure the current  and it gives me another value of resistance again different from the previous and also the polarization isn't verified so it's not certainly the right way but maybe it's closer? ...

Which way would be the proper one?
*Updated as Zero999 said
Zero999:
I can't see the schematic because it's blocked by the firewall. Please upload it as an attachment, that way this thread still makes sense if the external hosting site goes down.

I haven't used PSpice before, but LTSpice which is based on the same SPICE engine so should be similar. The impedance can be plotted by performing an AC analysis and plotting V/I.
iMo:
In LTSpice: Use 1A AC current source, do AC analysis and set plot to Bode, set the dB axis to Linear.
Attach the 1A current source into the points where you want to measure.
"15kV" then means "15kOhm".
Example below.
bonzer:
Thanks! This works!
iMo:
You may use 1uA AC current source, of course.
5mV then means 5kOhm.
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