Hi MIke
What component type are you using for the test? Trying to understand why the R is changing myself. I would think the resistance of a fixed series resistor would remain fairly constant if it has low reactance itself. PA3A's article shows an example of measuring the Q of an inductor so it is understandable that he would measure a Q of over 200 and a low resistance for the iron powder Micrometals core. His R stays flat as would be expected. I am not familiar with the 4C65.
Vector network analyzers were not the preferred instrument to us for measuring the Q of a coil. The R is so small with respect to the reactance that small variations of the phase angle and magnitudes of the reflection coefficient would make the Q and the calculated R to vary considerably. The old Q meters remained in favor for many years because they used a parallel tuned circuit method (old Boonton Radio Corp 160 and the HP 4342 for instance). In any case it would be interesting to know what type of inductor you are testing. What is the core?
73, Pete
