Characterizing the Antenna
This method uses a signal generator, oscilloscope and impedance bridge. (See "Building an Impedance Bridge" below.) A spectrum analyzer, frequency-selective voltmeter or S-meter equipped receiver could be used in place of the oscilloscope. A spectrum analyzer equipped with a tracking generator can replace both the oscilloscope and the signal generator. You will also need a multimeter and a capacitance meter.
First pass - find the resistive (real) component