Counterpoise

[WRXR255]

AKA Tiger Tail / Scorpion Tail...

I hear and see mixed information on if something like this helps or not generally on HT use.

I am mixed personally on it as I have sometimes had one hanging off my HT, and I THINK it helps a tiny bit, but I wonder if that's a kind of radio voodoo placebo effect.

What are your thoughts?

[WRUW493]

I have quite a bit of experience designing antennas for handheld devices...cell phones. The "ground" / "counterpoise", call it what you wish, is hugely important. It's the bottom half of the dipole antenna. My point is that without a counterpoise the upper half (whip, stubby, ducky etc) is not going to be able to have current driven into it well and thus will not radiate well. A real 1/2 wave dipole works very well of course. The metal in the talkie can and frequently does become the counterpoise especially at GMRS FREQS where a 1/4 wave is about 6 inches and that is the height of many talkies. Those smaller talkies, you know which ones, suffer from a much shorter counterpoise and unless the manufacturer has gone to extremes to make their metal housing have extra electrical length, those talkies never will perform as a longer/taller talkie. It's basic EM. 

Back to the original question about a counterpoise: yes, it can help especially in the case where the talkie is not close to 1/4 wave. Hanging a 1/4 wave wire from the base of the antenna downwards has some chance of making a difference, probably a lot of difference on the smaller talkies. 

I would be remiss if I didn't mention those longer whip antennas. A 5/8 wave whip antenna has "gain" over a dipole, around 2dBd, but ONLY if it has a substantial ground plane below it. Something in the order of 1-2 wavelengths in radius is required. The reason is that if you look at the E and H distributions you'll find that they only add towards the horizon when the ground plane is at least that big. If it's smaller, the radiation pattern turns into a  butterfly shape and the peak gain goes down actually getting lower than a 1/2 wave dipole. Thus I am not a proponent of the longer whip antennas, contrary to a long line of people who claim to get actual better performance with them. To them I challenge that they are basically doing annedocital testing where they are finding better results in only one location/position and to one remote location. If their setup were taken into a true antenna anechoic chamber it would show otherwise.

The best we can do for a talkie is a 1/4 wave whip on top of a 1/4 wave talkie. This gives the best efficiency with a rather good donut shaped radiation pattern which gives the best chance of good range in a variety of use cases and scattering environments. Shorter ducky antennas suffer from efficiency loss...they have to compared to a straight 1/4 wave whip, it's in the math. 

Hope this helps and does not ruffle too many feathers

 

 

 

[OffRoaderX]

I've tested this 100-ways to Sunday.. and even Monday..

My results show that it might help.. a little.. maybe?.. on some radios.. I think?  Basically, any improvement was so slight, i wasn't even sure if it was an improvement or just my very vivid imagination, and it certainly wasn't worth risking my reputation by looking dumb walking around with a piece of wire wagging from my radio.

It should be noted that it almost always did show an improvement in SWR on my meter - but, a slightly lower SWR does not necessarily mean more farz

[WRXR255]

2 minutes ago, OffRoaderX said:

I've tested this 100-ways to Sunday.. and even Monday..

My results show that it might help.. a little.. maybe?.. on some radios.. I think?  Basically, any improvement was so slight, i wasn't even sure if it was an improvement or just my very vivid imagination, and it certainly wasn't worth risking my reputation by looking dumb walking around with a piece of wire wagging from my radio.

It should be noted that it almost always did show an improvement in SWR on my meter - but, a slightly lower SWR does not necessarily mean more farz

Kinda my thought as well, but I have to admit I think a properly affixed HT to your hip, within FCC requirements VIA belt clip...

Im going to contrary to the look however.  I think you will impress those as they will look at it thinking - they know what they are doing, and ask, are you on Grindr?

[back4more70]

The tiger tail is 80's approved

[AdmiralCochrane]

I have confirmed that it does give a minimal amount of help at the fringes.  I also confirm that it does matter which way it faces.  Apparently adds a little bit of antenna polarization. 

A location where I routinely activated a repeater from 18 or 20 miles away from the top of a 14 story building I could also work the repeater from ground level with the tiger tail oriented toward or away from the repeater but not perpendicular to the repeater. It did not make my signal understandable.  From the roof with the tiger tail my signal report was no detectible difference hanging down but the same + at 0° and 180° and some decrease at 90° and 270°.  Without the tiger tail I could make a difference by moving to different spots on the roof.  I knew exactly where to stand to get the best propagation. 

If you are using a rubber duck, factory original garbage or counterfeit Nagoya a tiger tail isn't going to help as much as a buying genuine Nagoya. 

[RGB]

Greetings,

I recently tested lots of HT antennas for GMRS and tried a counterpoise. My experience is similar to others here—it made little difference and it did not make HT antenna performance more predictable. (I was more interested in predictability than lowest VSR. And the best way to increase predictability is to get away from objects that couple to the antenna, affecting its operation.)

As for Nagoya, I must disagree. I recently tested and measured six Nagoya antennas and the most disappointing observation was sloppy tuning. For example, three NA-771G were tuned to 457, 458 and 457 MHz. This was far enough away from optimal GMRS tuning to raise their VSR from 1.3 (best case) to 1.6 (worst case). These antennas could have been down in the 1.1xx range if they had been tuned to 465 MHz as they should have.

The GMRS antenna for HT that was the best was the 15.3-inch HYS GMRS whip here. I tested two of them and they were both reliably tuned to 465 MHz and demonstrated VSRs from 1.11 to 1.16. And this was immediately apparent when using them—my radios easily picked up signals that the Nagoyas could not. But there are two caveats to the HYS antenna: it uses a BNC connector and, at 15.3 inches, it is quite long. I prefer the BNC and I have adapters on most of my HTs so I don't wear out their SMA connectors (I change antennas a lot, depending on the application).

Kind regards, RGB

[WRQC527]

On 4/5/2024 at 4:19 PM, OffRoaderX said:

I've tested this 100-ways to Sunday.. and even Monday..

My results show that it might help.. a little.. maybe?.. on some radios.. I think?  Basically, any improvement was so slight, i wasn't even sure if it was an improvement or just my very vivid imagination, and it certainly wasn't worth risking my reputation by looking dumb walking around with a piece of wire wagging from my radio.

It should be noted that it almost always did show an improvement in SWR on my meter - but, a slightly lower SWR does not necessarily mean more farz

But wait... There's expert(s) like this guy who produce videos that say it will double my HT's range! Double, I tell ya! That's like twice the range! Two times the farz! It's a modern-day miracle!

https://codegreenprep.com/2013/07/the-ten-cent-modification-you-can-do-to-double-your-radios-range/

[OffRoaderX]

I'm not saying it CANT.. it MIGHT.. so it "can"... just never did much good for me.

[WRQC527]

I tried it once because I had an extra ten cents, and I found that it had absolutely no effect. Except right now I could really use that dime back.

[WRWE456]

I have heard that your body acts as a ground plane or counterpoise so it depends if you are holding the radio or not. That is why it is difficult to get meaningful SWR readings from hand held radios. Maybe one of our resident experts will comment on this?

[WRXB215]

4 hours ago, WRWE456 said:

I have heard that your body acts as a ground plane or counterpoise so it depends if you are holding the radio or not.

Seems like I've heard Randy and Josh both mention this. I think one of them said that many radios are even tested this way at the factory.

[WRUW493]

On 4/10/2024 at 7:50 AM, WRWE456 said:

I have heard that your body acts as a ground plane or counterpoise so it depends if you are holding the radio or not. That is why it is difficult to get meaningful SWR readings from hand held radios. Maybe one of our resident experts will comment on this?

Interesting point on the human body. But I suspect that human tissue is quite lossy at these freqs. I know for sure that it is lossy at 800MHz and also at 150MHz, so most likely also at 460MHz.

Way back in the stone age at Motorola, with one way pagers, remember those....there was a model called the PageBoy II. It had a short hairpin antenna around the outside of the case that when belt worn would couple the magnetic field to the RF currents running along the length of the body. But it should be noted that although this was the "best" position on the human body, that this was still lossy compared to free space for example. It was assumed that the pager would mostly be worn on the body somewhere, and on the belt near the center of a 6ft tall person was typical, and at 150MHz a 6ft person is around 1/2 wavelength tall. Thus near the center of this 1/2 wave lossy body is where the current is maximum, thus the PageBoy II antenna would couple to that. Just a tad of history for you history folks

 

[WRWE456]

Interesting! Thanks for sharing that bit of history.

[WRQC527]

On 4/5/2024 at 4:09 PM, WRXR255 said:

I hear and see mixed information on if something like this helps or not generally on HT use.

Consider this, if you will. HTs have been around for quite a while. I have both a Yaesu 2-meter handheld and a handheld Icom airband transceiver from the mid-1980s, and I have a variety of much newer HTs. In all that time, I have never seen a factory-supplied counterpoise, or a factory-designed way to install one. The manufacturers of HTs, who have all manner of RF and electronics experts designing these radios, have not seen fit to either provide or even recommend counterpoises. Because they've designed these radios to operate adequately in the hand of an operator, or with an external antenna.

[Lscott]

10 minutes ago, WRQC527 said:

Because they've designed these radios to operate adequately in the hand of an operator

But you also see a lot of them hanging on the user's belt, in pockets and strapped to utility vests. Some even have provisions for sticking the antenna on the speaker microphone. Can't design for every usage condition.

[WRQC527]

8 minutes ago, Lscott said:

But you also see a lot of them hanging on the user's belt, in pockets and strapped to utility vests. Some even have provisions for sticking the antenna on the speaker microphone. Can't design for every usage condition.

True. I use my HTs when I'm hiking, usually attached to the front of the shoulder strap on my backpack, with a speaker microphone. I suspect that the speaker mic cord "sort of" acts as a counterpoise, but when I set my HT on my desk with a speaker mic attached, the reception actually gets worse. Antenna theory is voodoo science if you ask me. 

[Lscott]

9 minutes ago, WRQC527 said:

Antenna theory is voodoo science if you ask me. 

Not really. The ideas are fairly basic if you don't jump into the theory really deep. Doing some searching on the Internet one can find some sites that do a decent job of explaining the fundamentals. If you get into building and designing antennas a bit more knowledge is required.  

[tweiss3]

32 minutes ago, WRQC527 said:

True. I use my HTs when I'm hiking, usually attached to the front of the shoulder strap on my backpack, with a speaker microphone. I suspect that the speaker mic cord "sort of" acts as a counterpoise, but when I set my HT on my desk with a speaker mic attached, the reception actually gets worse. Antenna theory is voodoo science if you ask me. 

No, the RSM cord is not used as a counterpoise. On some it was used as an extension for the antenna to get RF above the user (see @Lscott above), but it's designed to be isolated from the RF. Kenwood actually had to redesign the KMC-45 to the KMC-45D to add additional isolation because the DMR TDMA RF was causing issues with the audio circuit. 

The reason you are probably getting worse reception is due to its proximity to your computer/monitor/etc. You have to remember, almost everything today that has electricity running through it does and can cause RFI and make "radio" frustrating to use and track down this interference. 

For example, I live 1.5 miles south of 1350AM (5kW) and 98.1FM (50kW) and 1 mile north of 1150AM (5kW), and boy does their mix cause an issue on some bands. 

[WRQC527]

45 minutes ago, Lscott said:

If you get into building and designing antennas a bit more knowledge is required.

I build all my antennas for HF and VHF. Pretty darn good ones actually.

[WRYZ926]

Computer monitors definitely can cause interference on certain frequencies. I notice interference from my monitors on hand held radios on certain 2m, 70cm, and GMRS frequencies. And I have clamp on ferrite beads on all the cables.