Greetings, The open, Short, Load calibration is fine for single port measurement. However, there are two additional calibrations to be completed when you intend to perform two port measurements. There is the isolation which is sometimes done just leaving both ports open.I have also seen where it is suggested to put 50 ohm calibration loads on both s11 and s21(if you have them). Last is Thru (you probably have that on your test board) If not, you can just use a jumper from S11 to S21 for the calibration. This is my two cents worth, others may wish to comment further.Good Luck73
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On Sunday, February 5, 2023 at 03:36:54 PM EST, PDXer <budkor22@...> wrote:
I received the RF Demo kit for NanoVNA. The cables are indeed fiddly to attach on the pcb board, but I am getting used to it. Just hope that it will last for some long time rather than get mangled, and ruin my investment for the learning.
Anyhow I got it to calibrate OK for Open, Short and Load with the Demo Kit board and supplied cables.
But when I tried to read for the 30Mhz Band Pass Filter, the readings on the screen didn't come out what is indicated on the board. It was more squiggly curve type graphs on the display. I tried to change the settings with the SPAN and SCALE in the menu, but it made it actually worse or was just showing straight horizontal line.
Could someone please explain, what settings the VNA must have to display nice sharp dip of the graph as on the board? What am I doing wrong. I understand the RF board is showing how the band pass filter on the board is blocking the all other frequencies and only letting in 30Mhz in the filter? What should be the settings in the menu of the VNA? Thanks
