Hello,
Tell me if you have checked the SOL terminations on another VNA? Also, I found that I needed a warm and fuzzy check when using the VNA so built up a couple reactive terminations. That is, a PCB mount male connector with a series chip 50 ohm 1% resistor and a series chip capacitor. The cap value is selected to be -j50 at some frequency of choice. I made two. One with the design frequency of 1 MHz and used a value of C of 3185 pF. and one at 10 MHz with a selected value of 318.5 pF.
Notice the C is proportional to the frequency. After calibration and when I want to use the device I put on the reactive load to confirm it reads the right 50-j50 on the design frequency. I know then that the calibration is linear across the bands of interest, Yes, you can build one for any frequency, you want just use 1% components or select them carefully. Works for me. Warm and fuzzy.
Mel, K6KBE
