Measure unknown RL (top left) by varying two resistors (bottom left and bottom right) independent of frequency. Diagonal voltage (measured with voltmeter) must be zero.
Names of elements:
. . . . . . .
Rx .
Lx R3
. .
. .
. .
R2 R4
L2 .
. . . . . . .
Computation of unknown elements:
Zx / Z2 = Z3 / Z4
Zx = Z2 * Z3 / Z4
(everything on the right must be known!)
...some steps in between...
Rx = R2 * R3 / R4
Lx = L2 * R3 / R4
Problem: In practice, it is very difficult to find right resistor values such that amplitude AND phase of the diagonal voltage is zero. You could e.g. use an oscilloscope in xy mode for that.
