Does size really matter?

[JerryS]

I have been to a number of different amateur radio forums, and also some of the vintage military radio forums, and I read a lot about a bigger antenna is better. So I ask them why and if one word could describe the answer it is “Because” and I also hear “You need to learn about it you’re self that is what Ham is all about”. It is the same attitude that a lot of Linux forums have, that why I don’t use Linux and why becoming a Ham kind of has a bad taste in my mouth.

So if someone would “check my math”.

Quality counts. Cheap Chinese crap is a bad Idea.

A quality Antenna with a good ground plane for mobile is a must.

A quality Antenna for a handheld is a must. Still confused about if longer is better.

Quality connectors, and as few as possible.

Still confused about Co-ax. I have read that a bigger size at 50ohm will handle more power (i.e. RG-58 for mobile) compared to smaller size (i.e. RG-316@50ohm used to relocate a handheld antenna)

I won’t even pretend to know anything about SWR (still working on that one when I have more time)

My assumption about a longer antenna for a hand held is so that it is not blocked by the body. Does SWR have anything to do with it? I am basing my assumption on how I have seen the handheld carried higher on the body or that the antenna of the handheld has been relocated to behind the shoulder on the back of the combat vest. I have also seen operators holding their radios up when TX’s

AMU (Antenna Matching Unit). This comes with one of the military stile manpack antennas that that is made by RACAL that I am looking at. What Is It?

Thanks
JerryS

[4n6inv]

A simple and probably stupid analogy from me would be: "Is it easier to catch a butterfly with a 3" net or a 12" net?" Sure; you can catch it with a 3", but when you're trying to absorb something; my rule is: The larger the surface area, the better. That, of course can have consequences if you're in a flooded RF area. There are many other structural considerations and design ideas with antennas; but, that is my basic rule of thumb. I've seen smaller ones outperform larger ones, but there is a science in the manufacturing that's going to cost you in most cases. Basically; if the same inginuity and cosntruction were employed on a similar, but larger antenna; it would ourperform the smaller one.

[Bill_G]

This follows a similar thread a while back about antenna gain. Depends on what you want to do. Bigger isn't always better, and quality speaks for itself.

[JerryS]

With amature radio receiving a bad rap in the eye of the police, news, and general public this last year, not to mention the older hams and there attitude I am trying to find a happy medium. I don't want to look like I have "Police Equipment", and give the cops around here, not to mention the gangs an excuse to "check things out". I have even stoped "carrying" so if I do get pulled over I wont give the police a "Sphincter Attack" and an excuse to treat me like a criminal until I prove my innocence.

JerryS

[MT2000 man]

For me personally, I'm in a repeater-rich area, and I hardly ever find myself in a fringe area far far away from the repeaters. So, I use a smaller style NMO mounted "puck" antenna. Gets the job done great for my needs.

For someone that's in a terrain with many hills, mountains, buildings, are far from the repeater, etc. then a longer antenna would suffice.

[chrismoll12]

Size matters? Sometimes
For receiving or transmitting?
I could get a 40" antenna and hook it up to my 50 watt radio but I can do the same thing with a 20" antenna and 25 watts.

[JerryS]

There are two things that I have been able to determine.

1st It is important is that the Ohm’s match. All of the components should be at 50 ohm’s I.E Radio, Connectors, Coax, thru to Antenna.

2nd As the coax increases in size it will handle a grater load (watts) for longer runs with less signal loss.

JerryS

[Tom in D.C.]

You might want to get a tech book, such as the "ARRL Antenna Guide" and study it closely to understand the theory involved in antennas. As an example, your premise about eveything being at 50 ohms is strictly what we call a "design center" and means that this is the ideal radiation resistance of the antenna system, whereas in actuality it can vary quite a bit from that figure.

You might also want to seek out an amateur radio club that welcomes newcomers. Not all of them, I assure you, have that old curmudgeon attitude toward new people. The first thing to learn, and remember, is that no one in a technical endeavor ever knew everything from the beginning. Learning takes effort and, sometimes, hard work. The smartest people are the ones who readily admit that they don't know it all. With the availability of the internet today, digging out information has become a pretty simple task, so dig in and start researching the answers to your questions.

[Edited to show correct term that I couldn't think of when I wrote this.]

[JerryS]

You might want to get a tech book, such as the "ARRL Antenna Guide".

Its on the way ordered today.

Thank's

[Bill_G]

Good answer Tom.

[Jim202]

I have been to a number of different amateur radio forums, and also some of the vintage military radio forums, and I read a lot about a bigger antenna is better. So I ask them why and if one word could describe the answer it is “Because” and I also hear “You need to learn about it you’re self that is what Ham is all about”. It is the same attitude that a lot of Linux forums have, that why I don’t use Linux and why becoming a Ham kind of has a bad taste in my mouth.

So if someone would “check my math”.

Quality counts. Cheap Chinese crap is a bad Idea.

A quality Antenna with a good ground plane for mobile is a must.

A quality Antenna for a handheld is a must. Still confused about if longer is better.

Quality connectors, and as few as possible.

Still confused about Co-ax. I have read that a bigger size at 50ohm will handle more power (i.e. RG-58 for mobile) compared to smaller size (i.e. RG-316@50ohm used to relocate a handheld antenna)

I won’t even pretend to know anything about SWR (still working on that one when I have more time)

My assumption about a longer antenna for a hand held is so that it is not blocked by the body. Does SWR have anything to do with it? I am basing my assumption on how I have seen the handheld carried higher on the body or that the antenna of the handheld has been relocated to behind the shoulder on the back of the combat vest. I have also seen operators holding their radios up when TX’s

AMU (Antenna Matching Unit). This comes with one of the military stile manpack antennas that that is made by RACAL that I am looking at. What Is It?

Thanks
JerryS

It's always tuff starting out alone and in the dark. My early jump into radio was in Jr High school. At least
there I had others to chum with and learn from doing things in an electronics class in High School. After that.
the Army taught me a few tricks. When I got out of the Army, I managed to bump into a few ham radio guys
that took me under their wing and mentored me along.

I would try and locate on of the ham clubs that might be in your area. It might take some effort finding someone
that your comfortable with being around and can click with. What I mean by that is the both of you get along
and are willing to work with each other in learning. It is a two way street weather you want to believe it or
not. I have a couple of people at work that are always interested in learning new tricks. What it took me
some 45 plus years to learn, I can pass along different things and talents to them in just a couple of days of
having them look over my shoulder and tell them what, why and how as I do the different steps. One of them
is now working on studies for his ham ticket.

Be patient, it takes time for the different items to sink in and be understood. They didn't build Hoover Dam in
only a couple of days.

Jim

[com501]

On a side note, NEVER stop 'carrying'. Who cares what the police think? If you are legal, carry. CONCEALED means no one, not even a cop, needs to know you have it.

That being said, find a ham club. Go to one of their montly meetings (usually at a coffee shop in my area) and talk to different people. Buy them a cup of coffee, they'll appreciate it, and pick your 'Elmer'. You NEED to have someone help you with this stuff when you first get started.

[AL7OC]

Jerry - Welcome, and prepare to have fun learning and experimenting with radio and antennas. I'll presume that we are talking about mobile VHF/UHF antennas in this thread.

There is no one "best" antenna. It depends on your application. Part of the fun of learning is experimenting. Here's some ideas.

As other have suggested, don't go cheap. Get a good commercial grade antenna. It will last longer and be more reliable. NMO mounts on a car are low profile and allow changing antennas for different applications.

Sometimes smaller is better. Larger (1/2 and 5/8 wave) antennas are more likely to get busted or bent if you frequent parking garages other low clearance areas. In very hilly areas, sometimes a 1/4 wave antenna works better because it has a wider vertical beamwidth. As the antenna tilts with your vehicle, the wider vertical beamwidth will keep your signal more uniform at the horizon. We found this to be true in the very hilly Allegheny Highlands in PA.

If you have a fiberglass body on your vehicle, you're best off with a 1/2 wave antenna as they work reasonably well without a groundplane. They have a narrower vertical bandwidth than the 1/4 wave and provide some gain.

If you operate out in rural areas in relatively flat topography, free from overhead obstructions, the larger 5/8 wave antennas are the best bet as they focus and collect more energy at the horizon. These antennas don't work well when in contact or close proximity with overhead structures or vegetation.

Handheld antennas are always a compromise. You don't have a great groundplane, so performance is usually mediocre at best. Rubber duckie antennas are fine if you wear the radio on your belt, but they aren't too efficient. Longer 1/4, 1/2, or 5/8 wave whip antennas work better, but are more prone to poking you or getting busted off. Save them for stationary portable operation where you can hold the radio upright and away from your body.

So the "best" antenna depends on what you need for your particular app. Have fun playing with antennas. The ARRL Antenna Book is a good resource if you want to learn more.

-Pierre