Experiment #1: 1.5uH inductor in a breadboard



This verification experiment uses a known 1.5uH inductor connected to the VNA with a breadboard and a 6" piece of RG-174. With the 6" coax connected to the breadboard I run f_sweep_tr.py in reflection mode (option -tr) from 250kHz to 25MHz with the coax OPEN, with a SHORT, and with a 51 Ohm resistor load. This creates data files calib_refl_open, calib_refl_short and calib_refl_load in a seperate directory. Then I connect the 1.5uH inductor and run f_sweep_tr.py again, creating a data file 1.5uH_refl_raw. This is compensated with 
	$ ./refl_calc_1.py calib_refl_open calib_refl_short calib_refl_load 1.5uH_refl 1.5uH_refl_comp
and then display the results with an updated version of display_smith_data2.py which uses the reflection coefficients (Gamma) to compute and show the normalized R and jX and the actual resistance and value of inductance or capacitance in a 50 Ohm system (Zo = 50).

The displays:





where I'm pleased to see the displayed value of L remains between values like 1.396e-06 and 1.4326e-06 over the entire frequency sweep of 250kHz to 25Mhz.



Exp. 1a - This time I put a 50ft length of RG-58 coax inbetween the directional coupler and the breadboard. Then the system including the 50ft cable is calibrated (open, short, load) and when the same 1.5uH inductor is connected to the end of the coax, swept and plotted I get this similar result:





Note: The inductor is NOT a calibration standard, it is just a Jameco "1.5uH" inductor. Measured with an AADE LC meter for comparison, I get 1.56uH, an error of about 150nH in the first part and only 35nH in the long coax 2nd part.