On Sun, Feb 14, 2021 at 12:25 PM, Ed Krome wrote:
Thank you to all who replied. But, since the values I was seeing didn't match
prescribed values (and it was driving me a bit nuts), I tried the experimental
approach. I took a single RF Demo Kit board with the same cable. I carefully
calibrated my 3 nanoVNA's (nanoVNA 2.8", nanoVNA H4, nanoVNA SAA-2N), each
50kHz to 300MHz. Then I recorded the values of the components at position 7
(capacitor) and posn. 8 (inductor) at increments over the frequency range.
Ed there are two versions of the RF demo board and at least 3 manufacturers. The test positions are different between the two. Photos of each attached. You can see that positions 7 and 8 on the NWDZ board are a capacitor and inductor respectively. However on the more commonly available DeepElec board 7 is a resistor and cap in series and 8 is an inductor and cap in series.
Are you using the NWDZ board and are you using the short, open and load on that board to calibrate?
Roger
Roger Need
