Now having purchased a low cost vector impedance analyzer, I feel like I have a hammer and everything looks like a nail.

I’ve complained about questionably genuine NA771s before in my SignalStick review but I thought it might be fun to stick them on the analyzer, sweep them out and see how they compare.

Here it is, the N1201SA by Accuracy Agility Instrument.

(bloom is because it’s still got the screen cover on)

Notes

1. This isn’t entirely scientific. HT antennas are hard to measure because they’re to some extent tuned to be on a handheld, in your hand. I tried to keep things fairly consistent but the phone wasn’t always in the same place. This didn’t seem to change the measurements much.
2. I’ve done a second set of 2m tests holding the analyzer in my hand to see the difference. 70cm was pretty much the same but 2m changed a lot.
3. Handheld antennas can frequently have very poor VSWR because they’re often undersized. Especially on 2m. Given no feedline, there’s not as much loss from this as you’d think. There’s no “2:1 or better” here.
4. VSWR says little about antenna radiation performance. A 50 ohm dummy load is 1:1 VSWR, but a terrible antenna. This is an exercise in characterising antennas not comparing performance.
5. The analyzer can’t do screenshots. Sorry.
6. The analyzer costs an order of magnitude less (~$300) than a “proper” one. It’s probably not as accurate, but should give you a general idea of what an antenna’s good for.
7. The “marker” feature on the graph screen gets a slightly diffrerent result to the single frequency test. It’s not me moving the analyzer, it does this on fixed antennas too.

Antenna 1: NA771 (possibly genuine)?

This one is 390mm long from base to tip, and has silver Nagoya printing, with the NA in Nagoya being in the same font. The back has a QRCode on it to http://www.nagoya.com.tw.

Antenna 2: NA771 (definitely fake)

This one is 385mm long from base to tip, and has white Nagoya printing, with the NA in Nagoya being in the wrong font. No other markings are present.

Also, you can see from the graph that it’s very different to Antenna #1.

Antenna 3: NA771 (definitely fake)

Looks exactly the same as Antenna #2. #1 and #2 came from one seller when I ordered 2, #3 and #4 came from another - yes I got different antennas in the same purchase and the seller claimed both were genuine even though they were clearly different.

Antenna 4: NA771 (definitely fake but different)

Another fake NA771 here. Nagoya branding is on a foil sticker. Antenna is noticably longer than the others, at 410mm.

Antenna 5: SignalStick

Let’s put the SignalStick through the same test to get some numbers to compare and contrast

As it’s made of nitinol wire, you can of course coil it up. I wonder how it performs…

Well, the VSWR isn’t bad - in fact it’s better than when it’s uncoiled, but I do wonder what the radiation pattern would be…