An antenna analyzer is a tool that every ham should have access to. Especially if you build antennas.
What is an antenna analyzer?
They give you important information about your antenna. At a minimum, they should tell you the impedance of an antenna at a given frequency.
Can I test antennas with other tools?
You can, but few will give you the depth of info that an antenna analyzer can. A grid dip meter can give the resonance of an antenna, but this will not tell the impedance.
A multimeter will tell you if there is a DC short, especially for a short to the shield. But it only tests for DC resistance, not impedance at RF frequencies.
How do I use an antenna analyzer?
Connect the coax to the analyzer, and connect it to the antenna. Use a short piece of coax – You want to test the antenna, not the coax.
Turn on the analyzer and set it to SWR.
Change the frequency to the desired test frequency. Try to use the center of the band to get the most accurate reading.
Notice the SWR. The lowest is 1:1. Sweep lower and higher than the center frequency. Find the dip in SWR for the band.
Make adjustments to the antenna. Test with the analyzer again.
What is a good SWR?
This depends. You may not get a perfect match when setting up an antenna. As long as the dip is in the middle of the band, you should be fine. If the SWR is not perfect, you can use a tuner to get the SWR to 1:1.
If the SWR dip is not perfect, you can use an antenna tuner to improve the SWR even more. READ ABOUT THOSE HERE.
Here are some popular antenna analyzer brands:
NanoVNA – $ – Advanced tool for an advanced user
If you like to tinker, this analyzer is for you. It is claimed to be the most capable analyzer, but it is the hardest to learn. They may also need to be calibrated before use.
*I personally do not own one of these, but I have always wanted to try one.
MFJ – $$- Common and Simple to Use
MFJ antenna analyzers are probably the most common analyzers out there. They are basic, but work well enough for the average ham. Most will measure impedance for HF/VHF frequencies. MFJ may be closed, but there are still lots of MFJ analyzers out there.
*I started with one of these. I used it to tune my screwdriver coil vertical antenna. It worked very well. I lent it out, and I don’t think it came back.
RigExpert $$$ – Premium features, powerful and very easy to use
Rigexperts are the premium choice for analyzers. They are extremely easy to use and have nice displays to see all the important antenna information.
*I recently got one of these to replace my missing MFJ analyzer. The Rigexpert is very capable for all antenna measurements. I was testing the capacitance and inductance of an HF loop, and its readings are the reason I got it working.
