23cm band HT antennas

Left to right -  Nagoya 701 / Alinco G7 rubber duck / Baofeng UV3R rubber duck.

I have recently renewed my 23cm band interest, and decided to look at the performance of some rubber ducks. I own an Alinco G7 triband HT, but I'm also looking to expand with the view to converting a cheap Quansheng HT, details here. Some surprising information came to light. But first here's a brief description of each rubber duck.

The Nagoya 701 is about 20cm long. It is sold as a 2m/70cm dual band antenna, and not for 23cm. The Alinco rubber duck is that which is supplied with the G7 handheld transceiver as a 2m/70/23cm band antenna. The Baofeng UV3R HT antenna is the wild card here. It's supplied as a 2m/70 dualbander antenna, and for some reason I just happened to decide to measure it.  I'm glad I did, it works very well !

The results are shown below. Test method for field strength - I rigged up my spectrum analyser on 1.2Ghz to get a set of relative field strength measurements to compare each antenna. The spectrum analyser had a basic quarter wave vertical connected to the input via a 40db pad.  The signal source was my Alinco G7  at 100mw output a few meters away.

For return loss measurements each rubber duck was attached directly to the SMA connector of the VNA. I also ran some sanity tests, which included measuring the return loss / impedance via a short length of RG174 coax, direct to SMA on the VNA as well as attaching an addition radial(s) to the ground or earth side of the VNA input to see what difference it made (nothing of note of course).

BEST TO WORST.

Alinco G7 antenna part number EA-163:   -44dbm

Baofeng UV3R antenna: -45dbm

Nagoya 701 antenna: - 61dbm (in vertical mode) and -48dbm in horizontal mode.

The Nagoya 701 is basically a one wavelength long antenna, shooting up it's power high into the sky so it's useless for a handheld rig when vertical. It works better when horizontal. OK if you are working someone who is horizontally polarised, but it's still some 4db worse due to it's poor match at the Region 1 FM simplex frequencies (1297Mhz). But also note that the match improves much lower down in frequency at 1246Mhz.  On air tests over a path of about two miles were conducted to see if there was any practical difference between the matched frequency range and the non matched. No improvement was noted, it was a flop. The Nagoya 701 might be providing a good return loss figure but it sure aint radiating !

Return loss and Smith Chart of Alinco antenna.

Return loss and Smith Chart of Baofeng UV3R antenna.

Return loss and Smith Chart of Nagoya 701 antenna.

General usage throughout the bands of all three on 23cm. The antenna that is supplied with the Alinco G7 triband HT is the best for the band, followed by the wild card rubber duck that comes supplied with the cheap Baofeng UV3R HT. The Nagoya 701 is a flop on 23cm. 

One 2m/70cm - the Nagoya 701 is king, the Alinco is close and the little rubber duck supplied with the Baofeng UV3R HT is a bit poor. But of course, convenient if in a high signal strength area. 

Bonus link to 2M/70CM return loss plots.