How do you calculate intrinsic impedance?

Question

What method is used to calculate impedance of a signal generator output?

Answer 1

Strange..

  If it's video it should be 75 Ohms. In general ( Not sure if this applies to what your doing)

Impedance is the total resistance of a circuit. Loads in series add and loads in parallel divide. A multimeter can be used to measure total resistance. In the case ot a signal generator, I suspect I'd look at the manufactures specs.

Answer 2

If you are using a Signal generator and are worried about front end load of a circuit, you will most likely need to contact the manufacture of the signal generator.

These types of test equipment generally do not have a even response curve, you may want to look in any documentation available for that specific unit. In my experience this is generally provided.