An antenna analyser question. I have a MFJ-266B, note the “B”, the later improved version, and have had it for checking HF antennas for about 10 years. It always gives the same SWR as a meter on HF, so I have never suspected it, or doubted it, until today.

Today, as it is my birthday, and I fancied spending it playing radio, I thought I would have a go at making a home made mobile 2/70 antenna on a quick release to go on my cars mag mount.

With all the components assembled, I am expecting a 1/4 wave to be between 19″ and 20″ to be resonant around 145 MHz and 435MHz ish.

The analyser shows the 19.4″ whip to be resonant at 113MHz, 130MHz, 446MHz, and 471MHz. No amount of adjusting the length of the whip causes the analyser to deviate from these resonant frequencies.

These numbers just don’t look correct. Surely, the UHF readings should be somewhere near a multiple of x3 of the VHF resonant frequency.

Putting my 10m antenna on the car, it shows a resonant frequency with the analyser of 28 MHz, which is expected, as I also use this antenna for UK FM CB as well as for 10m.

I have never used this analyser for VHF and UHF before, and I am suspecting it is not reading correctly above HF.

Has anyone used an MFJ-266B for VHF/UHF before? And, how accurate are they on these higher bands?  Thoughts everyone please…

Kindest 73’s,
Mark M0INI
mark@m0ini.radio

#AntennaAnalyser #MFJ266B #M0INI