On Sun, Feb 23, 2025 at 07:52 AM, Team-SIM SIM-Mode wrote:
MFJ company says that MFJ259 antenna analyser becomes inaccurate when
measuring reactances below 7 Ohm or above 650 Ohm, i am really impressed with
the good S21 responses you have even with a high value Z Renormalisation as
440 , Congratulations, may be NanoVna-H4 has a little more dynamic range then
MFJ instrument
I own an MFJ259, a RigExpert AA-55 and a NanoVNA H & H4. The MFJ is the poorest performer of the bunch and not really useful for measuring resistance or reactance to any degree of accuracy. The RigExpert and NanoVNA are much better when used as one port VNA's for impedance measurements over a range of 1 to 3000 ohms. Some plots of the NanoVNA measuring components is attached. Results are quite good in my opinion.
Roger Need
