Decent handheld antennas?

[Chickenhawk56]

There's your problem. The 701 is tuned for ham band, not commercial uhf. They make a separate 701C model for commercial and gmrs frequencies.

It was the NA-701C. I tested it in the band it is designed for. (453, 462 and 464 MHz)

I have noticed the same issue with almost all my HT antennas: SWR is way crazy for the band I would like to use it for.
I had bought a Surecom SA-250 Antenna Analyzer and proceeded to "fix" these antennas. Almost all of them were too long and could easily cut them down to reach my target frequency. First I took the plastic tip off the end of the antenna, then cut a small piece off. I was sure to put the little tip back on before testing because it does make or break the tuning.

Interesting idea!

It was worth a try ... considering I now have three almost useless antennas. I checked SWR on the lowest frequency I was licenced for (453) and the highest frequency I was licenced for (467) and the SWR was lower on the lower frequency. This indicates an antenna a bit too long. Considering the resonant frequency of the NA-701C should be 455 MHz, I felt is was worth a try. I snipped 1/4" off the end and replaced the end cap, exactly as my friend has suggested above. I tried it at exactly 455. SWR actually went down. Woohoo!

Sadly, it only went down from 9.01 to 8.6. Rats.

Just for fun I decided to snip another 1/4" inch. Ooops. Too much. The SWR now climbed past 11.

Oh well. I was destined for the garbage can sooner or later anyway.

I am still convinced that Nagoya has been faking the old "fake" thing, and uses that as an excuse if anyone actually bench-tests their antennas and finds these crazy high SWR numbers.

What I cannot understand is how other reviewers report much lower (1.4 or so) numbers on the NA-701 (ham version of the 701C) and the NA-771 antennas.

 

[jonwienke]

Lack of a ground plane in your test setup.

 

[Chickenhawk56]

Lack of a ground plane in your test setup.

Sorry? Not sure if you read my post. It's a handheld, so the radio itself and the hand holding it acts as a bit of a groundplane. It's not ideal, but every antenna was tested in exactly the same conditions, and held in exactly the same way.

If it's a groundplane issue, then they would all have high SWR figures. Instead, one had 1.03 - which is pretty remarkable for a handheld antenna - and one had low 2s and 3s. The bad ones were 8 to 11 in SWR readings.

I was not asking how I could improve the performance of an antenna. I was asking if there is anyone who can provide good documented evidence about GOOD handheld antennas so I didn't waste any more money.

I was also asking why such a highly-rated antenna can perform so poorly. Could it be that it is just a crappy antenna, and all the "fake" and "genuine" business was just a marketing ploy?

I tested three identical ones. As Ian Fleming once said in 'Goldfinger,' "Once is happenstance. Twice is circumstance. Three times in enemy action."

 

[NC1]

I snipped 1/4" off the end and replaced the end cap, exactly as my friend has suggested above. I tried it at exactly 455. SWR actually went down. Woohoo!

Sadly, it only went down from 9.01 to 8.6. Rats.

Just for fun I decided to snip another 1/4" inch. Ooops. Too much. The SWR now climbed past 11.

Ouch. 1/4 inch at a time is far too much on a little HT antenna.
I took off about 1/16th and tested on the analyzer after every cut. It took more time, but I did not go past the point of no return. A little longer is acceptable.

On the bright side, you might be able to tune it for GMRS if you are careful.

That gives me an idea - I see a market for tuned antennas on ebay. Buy a bunch of knock-off antennas really cheap and tune them. Just put a picture of the Antenna Analyzer results showing the characteristics of the antenna and you should have a quick sale. Nobody else shows proof like that, and you are located in the US - that is two major advantages over the competition

 

[Chickenhawk56]

Thanks! I am pretty much giving up on cheap dual-band antennas when I need optimum transmit distance and readability. I am going to explore tuneable single-band antennas, cut to the length I need. I never realized 1/16" at a time was needed. That is very useful information!

Did you simply cut the antenna with sidecutters or did you unwrap the wire coil from underneath the coating and cut the actual wire itself? Would it make a difference?

 

[NC1]

T
Did you simply cut the antenna with sidecutters or did you unwrap the wire coil from underneath the coating and cut the actual wire itself? Would it make a difference?

I cut the jacket along with the wire inside, making a full clean cut in one shot. Snip just a little off at a time and keep checking where your lowest SWR is moving. Once you have successfully done one, then the routine is much easier the next time.

While looking for my Amphenol PL259's today, a plastic bag with a few HT antennas were uncovered. Maybe it's a good project for tomorrow to see where these are tuned and make some adjustments.

 

[Rred]

Chickenhawk-
You mention that dirty word, "durability". Your tests may eventually tell you something about performance, but that doesn't say squat about durability. While some antennas are fiberglass whips and pretty much inert, the short ones are all "elastomers". Rubber, plastic, whatever, and there is NO WAY to test those for durability without an environmental exposure lab or other inconvenient means.

Case in point, the pampered original antenna on my 13 year old Kenwood HT finally cracked the "rubber" this year. OK, not such a bad run. And the replacement I bought might even be another genuine Kenwood part, who knows. But I've also seen Motorola duckies that are 30 years old without cracking. And, more that had cracked, but the brass (?) coil wire inside was still perfectly good, just needed some liquid vinyl or heatshrink over that to make them secure again.

There's only so much you can measure, or guess at. As Tom said, you really need to analyze things, not just measure SWR. I can give you low SWR by making an antenna that simply absorbs all the TX power. That's great SWR but lousy performance, and an SWR meter would never show it.

I figure that while the big three are all very motivated to compete on price, they'd be fools to use cheap antennas when that is so critical to performance. Same thing with commercial radios. I'll try sticking to the OEM antenna unless I'm looking for something different for a different purpose. It just isn't worth the angst trying to figure out the rest, without real test equipment.

 

[Chickenhawk56]

You make some very good points. SWR is not everything and I am only using that as a starting point.

To me, all the test equipment in the world means nothing because I don't use these radios on the bench - I use them in the real world. This is why, no matter how much I test with an SWR meter and a field strength meter, my final test will always be to walk down the street with a radio and a pocket full of antennas, and see what I get for strength and readability at various distances. This way, I can compare back-to-back with a known good antenna. (Diamond RHC77A.)

At 15", the Diamond is just not practical for everyday use for my purposes, but I can use it to compare the other shorter ones to see what comes the closest.

Just to summarize, the SWR readings that I got on the test bench were pretty much supported in real world testing too. The antenna that tested at just over 1.03 (Diamond) was of course the best sounding and highest strength signal. Next was the OEM Retevis RHD-701. Worst sounding was the Nagoya NA-701C and the OEM Wouxun. This was borne out - and possibly predicted by, the bench-test SWR numbers.

This is why I am coming to the conclusion, based on my tests and input from you and many other members here, that:
1) Low SWR numbers will not always result in a good antenna, but
2) High SWR numbers will NEVER result in a good antenna, and
3) Most people won't notice a difference and will be quite happy with the OEM or the highly-rated Nagoya, even if they are not all that great.

Basically, if it tests okay on the bench, it might not test okay in real world back-to-back tests, but if it tests ****ty on the bench, it will still be ****ty in real world conditions.

Here is my plan of action. The Wouxun and Nagoya antennas go in the garbage. I ordered three Retevis antennas for everyday use (and will of course test them when they come in.) I also ordered three single-band antennas from Smiley that I will tune to the frequencies I need. If I am in a vehicle, I will use the Nagoya or the Tram mobile antennas because they tested very well on the bench and in the real world. If I am going to be in fringe areas and the longer length doesn't matter, I have the Diamond RH77CA. If I am in an area where I need the ultimate performance, I will switch out the OEM antennas for the tuned Smiley antennas.

Thanks to everyone for their inputs! I now have a much better idea how to tune an antenna! I will use a proper cable cutter, and take off 1/6" at a time, recording my SWR results as I go along. I am actually looking forward to this project, if nothing else than it puts actual numbers and head-to-head tests up to support what many people have been saying for years - handheld antennas are always a compromise of some kind.

The nice thing about this whole project is that I am really impressed with how well one can get a good radio to work with a good antenna, and especially impressed by the distances I am getting against some other - very expensive - business radios.

 

[Rred]

With all that talk of antenna swapping (I change shoes less often than that, but that's just me) there's another issue that should be mentioned.

You probably should be fitting a BNC adapter on your radio and getting all of your antennas with a BNC mount, not the standard SMA threads. This is because SMA was invented for the purpose of connecting sub-assemblies in a chassis, that would be connected once during manufacturing and then rarely if ever again used. They are prone to cross-threading when used frequently. And they are used on ht's for the same reason: The antenna is designed to be installed after shipping, and then pretty much left alone until years later when it needs replacement.

Yes, most of us have no problem with SMA's. But you should know, this is not what they are intended for. BNC connections *are* intended for this type of use. And way better at it.