rx8pilot:

For building up some confidence in the cal and measurements procedures, I'd recommend to rebuild the HP35676A test set:

http://hparchive.com/Manuals/HP-35676-SCHEMATIC.pdf

No need for all the fancy metalwork, and don't worry about the unknown capacitor, it still works built on a piece of SMT protoboard using some MiniMelf resistors (some of the series connected to get near the original value).

Once calibrated using the full cal procedure (again, no need for a fancy cal standards set, a wire and a 50 Ohm resistor works, you'll get some ripple at the 200MHz end), then switching the 3577A to impedance display (choose "F4" as the input to display , it's written somewhere in the manual), you can get impedance sweeps of known components (start with resistors in the 10 Ohm to k Ohm range) and get familiar with the way it works. Measure some inductors and capacitors, read the imaginary part at some frequencies and do the math to verify your reading. Inductors are quite fancy regarding their impedance over frequency, many of them are inductors at rather low frequencies only.

There's also somewhere a manual on the net (for this or the HP35677 test set) that has a better description of how to measure impedance using the 3577A than the 3577A manual.

Edit: Found it, here it is: https://cb.wunderkis.de/wk-pub/Keysight%2035676A%20Data%20Sheet.pdf

Edit 2: Don't know what you mean by "skewed", the manual has some tips regarding the RBW setting: Reverse the sweep direction and watch if the graph shifts. If it does, your sweep speed is to fast for the chosen RBW.

Edit 3: "F4" is impedance for a 50 Ohm system and calibration, "F5" is for 75 Ohm

Hi

I had planed to rebuilt the HP 35676 but I have some questions regarding it's operation as described in the manual.

First of all, if I look at this schematic, it seems to me that the 80R6 is the current sensing shunt resistor. The rest is pretty much a ~13dB T-attenuator for the reference input and a ~9dBm T-Attenuator on the voltage sensing A input. At least that is what I first thought.

But when I read the manual, I see that for one port measurment the A/R and for 2-port the B/R functions are applied. So this would mean measurements of "V" "only"(?) In this case I assume the 80R6 resistor is used to match the two T-Attenuators which don't seem to have a 50ohms input impeadance on their own.

But, what if one would like to do V/I measurments? Could I use the 80R6 resistor as a shunt like I first thought and measure voltage over the DUT on the A port, and current trough the DUT via R-B measurment and terminate the DUT either in 50ohms / B input for a 50Ohm system or lets say at ground for a capacitor / inductor with =/ 50ohms?