Antenna Question

[kc0zps]

I replaced the rubber duck antenna on my Yaesu VX-8R with a Comet SMA-24 17 inch whip antenna. I only did this because I was given the antenna for free by a fellow ham radio operator. As of recently, I've been thinking about going back to the rubber duck antenna.

Are there any actual benefits with using the 17" whip antenna with my HT? I obviously lose 6m capabilities, but will I gain anything on the 70cm and 2m band? Is there a difference between receiving or transmitting on such an antenna?

 

[KingCobra_CDX882]

The antennas that come with an HT basically suck..

However swapping or adding any number of aftermarket antennas
typically get better gain..
Better gain equals easier and better repeater usage
( better simplex as well )

Comet makes some very good antennas..
Oh...there is a down side..

If you ever find yourself getting on nyc subway..
You can expect many cops stopping you and asking all sorts of dumb questions and then being banned from using the subway
( No Joke there...Happened to me )

 

[W5LZ]

There should be a definite improvement on 2 meters. Probably some on 440, maybe. And you're right, 6 meters you can forget. If that 'fits' your use of that HT, good. If not, then don't throw that 'ducky' away, it's better than absolutely nothing... sort of.
- 'Doc

 

[Moleculo]

Replacing a stock duckie with a 17 inch whip antenna should make the handheld radio do pretty well. See if you can arrange to do a test with a simplex station swapping them back and forth and see for yourself.

 

[ke7vvt]

I'm going to pick on your statement Cobra-

The antennas that come with an HT basically suck..

Which are generally the short, ridged, and wide band. Which is exactly the antenna that you want to have with the an HT, short as possible, very durable, "works" on all TX bands. The only downside to the stock antennas is that they have lower gain relative to other antennas because of the traits mentioned above. The wide band trait causes most of this, with length being next. So how much does the gain matter in your communication abilities?

Theoretically, that 5dBi difference between a "good" antenna and the stock antenna doesn't make any difference at all- see the spreadsheet. If this is incorrect I would like to hear about it. You can change the TX power values and other things, it is kind of interesting. The free space loss is pretty dramatic. But according to this, I could talk to someone as far away as Cali if there was line of sight.

To find out how well the stock antenna really works in comparison to your Comet BNC24 and SMA24 Amateur HT Antennas you should carry it around and talk to someone while changing the transmit power and walking into/behind buildings and cars. See if it makes much difference, this is the best way to find out how much it helps. Afterwards you need to decide if the length of the antenna is worth the hassle.

 

[kc0zps]

Great post ke7vvt. I actually ran a quick test yesterday. While I did see a small difference between my comet whip antenna, for HT use, it wasn't all that great -- especially at the loss of portability that the rubber duck antenna provides. I want to run a few more tests, though. Anyway, my wife stayed at home and listened in on our Yaesu FT-60R. I called her several times using 55 watts on my ICOM 208H, the Yaesu VX-8R with the stock rubber duck antenna and Comet Whip Antenna @ 5 watts.

At 6 miles, my wife could hear me using my ICOM 208H @ 55 Watts only.
At 2.5 miles, my wife only heard very small fragments of my message using the whip antenna. Nothing was heard when I switched to the rubber duck antenna.
At .15 miles, she could hear me using all three methods.

I'd like to try these tests again as I move closer between 3 miles and about 1 mile.

 

[KingCobra_CDX882]

Well..

As example with my Icom T-90a or IC-91AD..

with stock antenna it hits repeaters 10-15 miles away (at best)
When i use a high gain antenna from street level ( on 70cm ) i can consistently and easily hit a repeater 65 miles away ( that with rubber duck antenna i can only hear it but not transmit to it)

 

[kc0zps]

Well..

As example with my Icom T-90a or IC-91AD..

with stock antenna it hits repeaters 10-15 miles away (at best)
When i use a high gain antenna from street level ( on 70cm ) i can consistently and easily hit a repeater 65 miles away ( that with rubber duck antenna i can only hear it but not transmit to it)

Wow, so you're getting a good additional ~50 miles with the high gain antenna? I did my tests with two ground stations. I need to run some tests with repeaters...

 

[W5LZ]

Just a couple of things to think about.
Comparing gain between two antennas that are not as good as a 'standard' antenna (dipole) only means that one of those antennas has less -negative- gain than the other. Neither will have 'gain' because neither will radiate as well or as much as a standard reference dipole antenna. A 'smaller' negative number is better than a 'larger' negative number, but neither is 'positive' so both are bad when compared to the "zero" standard antenna. Which is just a complicated way of saying that neither antenna is going to work very well. And relates directly to what do you expect to start with?
A 'ducky' antenna certainly makes a handy-talky more 'handy' to carry and use. And since HT's are only for convenience and short range, you get exactly what you paid for.

What's this preoccupation with range lately? Another silly idea is rating any radio, or antenna, by 'range'. Just too many variables for that sort of thing to ever have any meaning. And that's saying nothing about propagation. It also doesn't matter what band you're talking about, that applies to all of them. I can't be the only one who's noticed that, what's the deal?
- 'Doc

 

[kc0zps]

What's this preoccupation with range lately?
- 'Doc

Why wouldn't I be? Just one example, but I use APRS quite a bit when I'm traveling around on my motorcycle. I do it to document my ride and to let certain people know where I am. I actually used APRS to prove that I went a certain route when I did my "Iron Butt" certification ride.

Carrying the whip antenna can be a pain in the ass, so I'm just debating if the added "range" (if any) is worth the hassle. It would be worthless carrying around my HT for APRS use if I can never get into Digipeaters to begin with.

Not only that, but I'm just curious as to the knowledge behind how antenna's work. I've only been into amateur radio for a couple of years, so I'm still learning.

 

[W5LZ]

Maybe I didn't express that clearly enough, so let me rephrase it here.

Have you noticed how radio/antennas have gone to a 'range', or transmitting / receiving distance type of ability lately? A, "How much range can I expect from using a _ _ _ _?", sort of thing? Tell me how you can honestly answer a question like that, in miles. I've seen answers ranging from only mildly optimistic to absolutely ridiculous. I'll bet you have too.

How can anyone possibly answer that sort of question with out a huge number of 'qualifiers' in their answer? And since the person asking that sort of question can very, very seldom eliminate even a small number of those 'qualifiers', an honest and 'Realistic' answer is impossible (pun intended).

And just for grins, if you know of others wanting to prove they have "Butts of Iron", and who happen to be a 'radio' person, there are HF alternatives to VHF APRS. What bands or frequencies? Any of them that allow packet mode usage, 6 meters down to 160 meters. Using a hand-held gets sort of 'difficult' on HF though, not even worrying about a 'ducky' antenna.
- 'Doc


The last time I had any current knowledge about the "Iron Butt" runs was quite some time ago, so things can certainly have changed. Last I knew, you had to have written confirmation of date/time/location for check points. If APRS alone is acceptable now, I'd be very surprised. Just too easy to 'spoof'.

 

[kc0zps]

Maybe I didn't express that clearly enough, so let me rephrase it here.

Have you noticed how radio/antennas have gone to a 'range', or transmitting / receiving distance type of ability lately? A, "How much range can I expect from using a _ _ _ _?", sort of thing? Tell me how you can honestly answer a question like that, in miles. I've seen answers ranging from only mildly optimistic to absolutely ridiculous. I'll bet you have too.

Well, I'd assume that certain constants being the same, different antenna's have different ranges... or maybe I am misunderstanding something. Would "gain" be a better term to use? I'm just trying to understand what, if anything, do I gain by using a whip antenna vs. the rubber duck antenna when all other 'qualifiers' are the same.

The last time I had any current knowledge about the "Iron Butt" runs was quite some time ago, so things can certainly have changed. Last I knew, you had to have written confirmation of date/time/location for check points. If APRS alone is acceptable now, I'd be very surprised. Just too easy to 'spoof'.

Written confirmation of date/time/location is easier to spoof than APRS data, I'd think. Anyway, APRS alone would not have qualified me. I handed in several methods to prove my route, including random people signing my paper, gas station receipts, GPS data, APRS data, and my odometer.

 

[Moleculo]

Well, I'd assume that certain constants being the same, different antenna's have different ranges... or maybe I am misunderstanding something. Would "gain" be a better term to use? I'm just trying to understand what, if anything, do I gain by using a whip antenna vs. the rubber duck antenna when all other 'qualifiers' are the same.

I think it's fair to say that you can have better effective range using different antennas on your HT. Probably for HT antennas, it would be better to compare them using a term like "less loss" than "gain"...but we're really getting more complicated than necessary for conversation's sake. The conversation starts to get meaningless when you try to put out specific range numbers for antennas, though. For example, one person may get 20 miles of range, while another only gets 5 miles with the same antenna because of terrain differences. All you can really do is say that you compared the two antennas and report what you find in your circumstance.

Hope that helps a little.

 

[ke7vvt]

Just a couple of things to think about.
Comparing gain between two antennas that are not as good as a 'standard' antenna (dipole) only means that one of those antennas has less -negative- gain than the other. Neither will have 'gain' because neither will radiate as well or as much as a standard reference dipole antenna. A 'smaller' negative number is better than a 'larger' negative number, but neither is 'positive' so both are bad when compared to the "zero" standard antenna. Which is just a complicated way of saying that neither antenna is going to work very well. And relates directly to what do you expect to start with?
A 'ducky' antenna certainly makes a handy-talky more 'handy' to carry and use. And since HT's are only for convenience and short range, you get exactly what you paid for.

What's this preoccupation with range lately? Another silly idea is rating any radio, or antenna, by 'range'. Just too many variables for that sort of thing to ever have any meaning. And that's saying nothing about propagation. It also doesn't matter what band you're talking about, that applies to all of them. I can't be the only one who's noticed that, what's the deal?
- 'Doc

Great post. The answer to the range question is usually just a little more than the range you have with the stock antenna.

I haven't been able to figure out what negative gain means or looks like. A positive gain in dbi on a propagation pattern plot makes sense, but I haven't found one of those plots for negative dbi. It would make more sense, I think, to state antenna specs in terms of directivity as well as gain.

And since HT's are only for convenience and short range, you get exactly what you paid for.

In the antenna world, I think that you are not getting what you paid for, you are getting what you are getting. Paying more for an antenna usually means that it comes with coax and mount or is a longer ($ material).

Well, I'd assume that certain constants being the same, different antenna's have different ranges... or maybe I am misunderstanding something. Would "gain" be a better term to use? I'm just trying to understand what, if anything, do I gain by using a whip antenna vs. the rubber duck antenna when all other 'qualifiers' are the same.

Maybe misunderstanding partially. Different types of antennas have different ranges and propagation patterns. If you think about a dish antenna and .25 meter long omni-directional HT antenna, then yes. There will be much difference. Comparing a 9" and a 17" omni HT antenna, there is not much of a difference.

But if you are comparing your stock tri/quad-band antenna on the 8R with the 17" long 2m/440 antenna you should notice something.

"rubber-duck" and "whip" I think are just words that best describe an antenna. Rubber duckies are grippy rubber, relativly thick ~1cm, and short ~8". The whips are thinly coated with slipperyer plastic outside coating, relativly thick <.5cm, and longer ~17". As far as I know, this construction does not affect the "range" or gain of the antenna. Just how long it will last with how much abuse/bending it gets.

One more, stock rubber-duck radiating dummy load - derogatory term used to describe the antenna that the idiot radio manufacturers have piled up in a warehouse and are trying to get rid of so they package them with the expensive radios they sell. Also, they are in league with the antenna manufacturers. Seriously. If you have one of these get rid of it.

I guesstimate one would find at least this (one significant figure only on the %)

Compared to an 8" tri-band HT antenna
~8" dual band +10% range
~17" Tri-band +10%
~17" dual-band +20%

The ~ are there because the dual/tri bandedness of the antenna is dependent on length and what bands you want. Longer = a little more range, less bands = a little more range because the length is just right.

If you are going to "upgrade" from the stock antenna you start with getting rid of bands you can live without (upgrading right?) and then you should have only a few choices on length, shorter or longer. For the 2m/440 HT antenna that is about 8" or 17".

If the antenna is already about 8" and dual-band, buying another 8" dual-band antenna from Comet/Diamond/MFJ to get rid of the "stock rubber-duck radiating dummy load" won't do anything.

That being said, is it worth it to spend ~$30 on an antenna to get rid of the stock antenna? Maybe, this is pretty much what it comes down to.

1. Antenna is the same length and bandedness but from an antenna company? No.

2. Longer length and same bands? Eh, sure. If you don't mind carrying around a longer antenna. It will probably go from about 8" to 17" which is a bit more of a chore to keep from getting bent. The around ~8" range is really comfortable compared to the ~17" antennas. Personal preference and depends on antenna construction (bendy antennas are bendy).

3. Same length and less bands? I think so. You can have fun testing it at least and if you really didn't use 220Hz on your VX-8R or TH-F6A then you aren't losing anything you will miss. Could become a little longer depending on what bands there are.

4. Longer and less bands? If you can handle the length and don't miss the lost bands then definitely worth it. Is it really that much better compared what you had before? Probably not, that is the hard question to answer, but for $30 it is still a cool accessory to play with.

Buying a longer and less bands antenna feels better if you have a multi-band radio, because you keep the 8" tri-band antenna around for when you need it.

Here are some 2m/440 HT antennas that one might look at.

Bendy Diamond RHF40 Amateur HT Antenna

Telescopy Diamond RH789 SRH789 Antenna

Tilty Diamond RH707 Amateur HT Antenna

"Short" like stock antenna Diamond SRH320A Amateur HT Antennas

Long and Skinny Comet BNC24 and SMA24 Amateur HT Antennas

Long semi-flex Diamond RH77CA SRH77CA Antenna