Need An Elmers Advice on HT Antennas

[Diverdan86]

Afternoon Elmers, hoping you can set me straight on HT antennas.

I have always been under the impression that HT antennas, especially the rubber ducks, are crap and the radios themselves are actually designed to be able to handle the fact that they Tx with crap stock antennas. Obviously, an original Kenwood rubber duck is likely going to be better than an original BaoFeng antenna, but both would likely have high SWR and little to no gain. I have also understood the low power of the HT, generally 2 to 5 watts, enables them to handle a garbage antenna better than would something pushing 25/50/100 etc. watts.

If this is correct, why do so many experience hams freak out over aftermarket HT antenna SWR? It seems most would be better than the stock rubber duck; if not superior than, at least equal to rub duck performance and SWR.

Case in point, I have a friend who has a cheap $23 ham radio w/stock rubber duck, that he has been using almost nonstop for 4+ years on 2m, MURS, 220, 70cm, GMRS (yes, yes, I know, but that’s between him and the FCC). The point is his radio has not been ruined by high SWR and on field days everyone comments on how clean/clear/bar his little HT transmits.

Help me out, which is it, or is as usually the case, is it a combination of both? Thanks in advance.

73

 

[AK9R]

If this is correct, why do so many experience hams freak out over aftermarket HT antenna SWR?

It's a great mystery.

Whenever I see someone talking about the SWR of their favorite handheld rubber duck antenna, I cringe. SWR is not the only parameter when evaluating an antenna, though many hams appear to think so. And, connecting a handheld rubber duck antenna to a nanoVNA with the antenna just waving around at your bench or operating desk is not a proper way to test.

There seems to be a trend among new hams that if an amateur radio product, including handheld rubber duck antennas, is "reviewed" by their favorite YouTuber and sold through the YouTuber's Amazon affiliate link, then it must be good.

That said, I do commend Josh at Ham Radio Crash Course for trying to objectively test antennas for handheld radios.

 

[dlwtrunked]

Indeed true. So many think SWR is the only way to judge antenna as that is what they can measure. I have a dozen or so different HT antennas that I have compared on a dual bander by going remote to the same location why recording actual signal levels at home. There were distinct differences. Some (most?) of this was likely due to radiation pattern (transmitting signals above and below the horizon). And I have noted that at least 2 fake Nagoya NA-771 models are more common around here that the authentic (with one fake being roughly as good as the authentic and the other terrible). The ARRL would do a great service by doing professional tests of different HT antennas and publishing the results.

 

[Diverdan86]

It's a great mystery.

Whenever I see someone talking about the SWR of their favorite handheld rubber duck antenna, I cringe. SWR is not the only parameter when evaluating an antenna, though many hams appear to think so. And, connecting a handheld rubber duck antenna to a nanoVNA with the antenna just waving around at your bench or operating desk is not a proper way to test.

There seems to be a trend among new hams that if an amateur radio product, including handheld rubber duck antennas, is "reviewed" by their favorite YouTuber and sold through the YouTuber's Amazon affiliate link, then it must be good.

That said, I do comment Josh at Ham Radio Crash Course for trying to objectively test antennas for handheld radios.

Thank you for the clarification AK9R! Perhaps SWR is just the 'easiest' to measure/makes one sound like they know what they are talking about LOL

 

[mrweather]

Yep. A dummy load will give a great SWR but will radiate almost nothing.

 

[K6GBW]

Those extra-long Nagoya type antennas tend to work a bit better on 2 meters and a bit worse on 440. At least in my experience. I think it probably has something to do with your body acting as a ground plane. We've known for a long time that UHF is more appropriate for handheld radios since the radio chassis and, by extension, your body work as a better ground plane that is does on VHF. Around town I use the stock antenna on most radios and I only break out the longer antenna when I'm in the woods and using MURS.

 

[G7RUX]

Here are some return loss tests I performed on a small selection of HT antennas a little while ago. The results can be a little surprising.

Note that although a good match doesn’t necessarily equate to an effective antenna, it does help somewhat.

 

[Diverdan86]

Here are some return loss tests I performed on a small selection of HT antennas a little while ago. The results can be a little surprising.

Note that although a good match doesn’t necessarily equate to an effective antenna, it does help somewhat.

Wow, these look awesome, but can you please explain the X and Y axis?

 

[G7RUX]

Wow, these look awesome, but can you please explain the X and Y axis?

Of course.
The x-axis is frequency, usually from 100 or 140 MHz up to 500 MHz; labels should be visible on the graphs. I tended to put a marker on each of 145 and 435 MHz which should dictate the return loss on he (EU) band centres.
The y-axis is return loss, with zero at the top, so the deeper the dip the better the match to 50 Ohms. Calculators to convert this to VSWR exist online but in general a return loss of 10 dB equates to a 2:1 VSWR and 20 dB is around 1.2:1.

 

[Diverdan86]

Of course.
The x-axis is frequency, usually from 100 or 140 MHz up to 500 MHz; labels should be visible on the graphs. I tended to put a marker on each of 145 and 435 MHz which should dictate the return loss on he (EU) band centres.
The y-axis is return loss, with zero at the top, so the deeper the dip the better the match to 50 Ohms. Calculators to convert this to VSWR exist online but in general a return loss of 10 dB equates to a 2:1 VSWR and 20 dB is around 1.2:1.

Thank you sir! Wonderful information and explanation. Folks like you are what make amateur radio so enjoyable

 

[G7RUX]

Thank you sir! Wonderful information and explanation. Folks like you are what make amateur radio so enjoyable

You are most welcome and thank you!

 

[G7RUX]

So if you want to know how I made these measurements you need to understand a little about how the handheld is designed to operate.

Firstly, a handheld needs to work properly when either hand held, so capacitively coupled to a big bag of salty water (the operator!), or standing on a desk or clipped to something, so relying on itself as a ground plane. To mimic this I made a simple test fixture which is a handheld-sized diecast box with the necessary connector on the top and a coaxial fly lead with a ferrite bead or two on the cable to attempt to isolate the fixture from the length of coax. In any event, the coax is less than a metre long.

Secondly, the sweeps are repeated with the fixture held in the hand and with it mounted on a non-conducting structure…a wooden stick!

Third, the analyser (in this case an Anritsu Sitemaster S820E but there’s no reason why you couldn’t use a nanoVNA or similar…this is just what I have available) is calibrated using the usual open-short-load method but at the antenna connector on the test fixture.

Each measurement is repeated two or three times to be sure to get a consistent and representative plot, stored and annotated so it is clear which antenna it is relating to.

The measurements aren’t complex but just need a bit of patience and care. You could do your own with a nanoVNA and a specially made fixture isn’t necessarily needed, although I made one because I wanted to be sure I wasn’t sharing something which was misleading.

Now, interpreting the results is a different matter!
The return loss is an important measure since if you aren’t getting power into the antenna then it cannot radiate it, although a good SWR doesn’t necessarily mean the antenna is radiating well, just that the power gets into the antenna itself. As you might expect, a tiny “miracle” antenna might have a good match but is grossly inefficient so eg: a 2m quarter wave will almost always be a better antenna even if it’s not perfectly matched.

That said, I think the best 2/70 portable antenna I have in this set is the RH770 which is a sizeable telescopic antenna so not necessarily that practical on a small handheld.

I think the information from these sorts of measurements is useful in picking a suitable compromise between huge-but-efficient and conveniently-small-but-ineffective handheld antennas.

There are some things in life where size matters and this is one of them!