CB RADIO & HAM RADIO BEAM ANTENNAS

What are some good beams to buy or better yet make?

 

 

Yes I said make.

 

First lets discuss what are beams? How do they work? What do you need to install one? Are they really worth the effort?

A beam antenna is an antenna which radiates or receives greater power in specific directions allowing increased performance and reduced interference from unwanted sources. Directional antennas provide increased performance over omnidirectional antennas when a greater concentration of radiation in a certain direction is desired. Thats from Wikipedia...not me. And they said it better then probably I could have.

In fact lets listen to more of Wikipedia: When transmitting, a beam antenna  allows more of the transmitted power to be sent in the direction of the receiver, increasing the received signal strength. When receiving, a beam antenna captures more of the signal, again increasing signal strength. As a consequence of their directivity, directional beam antennas also send less (and receive less) signal from directions other than the main beam. This property can reduce interference.

The beam antenna consist of a dipole (surprise) as the driven element ( the one you connect the coax to) and a reflector ( a slightly larger element then the dipole element) and in the case of a 3 element beam also a director ( a slightly smaller element then the dipole (or driven element)). It looks like this:

All beams are built similar, you basically point it like an arrow. The smaller end goes in the direction of the signal you want to talk to or listen to. The larger REFLECTOR should be in the back of the antenna. The above is a 3 element Yagi antenna. Its considered the basic all-around beam for any frequency and works good.. The shape of the beam as you should imagine...focuses the signal you want to transmit or hear in the direction of the smaller director element.

 

The pink lines in all 3 pictures represent a line from ground level to straight up (zenith). The top left picture represents the antenna radiation pattern of a perfect half wave dipole in free space (explained in a bit). The right top picture represents the pattern of a really good Omni-Directional antenna, notice the signal is more concentrated towards the ground, where it should be for best results. Bottom picture is a good beam antenna pushing the signal in one direction along the ground. This view is from straight above the antenna, notice where the pink dot is. You are looking down at the pattern. If you were looking down at the first two pictures patterns you would just see a circle (360 degrees) of radiation. The top left picture is similar to the Antron 99 antenna pattern, and at the edge of the red circle picture the distance being 20 miles from your house (represented by the pink dot). The top right picture notice how the better omni-directional antenna has squashed the pattern down (like squashing a balloon) towards the ground, the edge of that red circle might be 30 miles away from your house, that you able to communicate. NOW...look at the bottom picture of the Beam Antenna, look at the edge of the red circle to the right, this distance might be 100 miles away from your house !

 

Are beams that much better then omni-directionals as far as gain goes? No question, absolutely positively YES. Above is a fairly typical example of a good multi-element beam versus an omni-directional antenna. There is just ZERO comparison. Omni's cannot come close. Remember not only are you transmitting in one direction you are also hearing only in one direction. By now you have reasoned your going to need something to turn this beam antenna. Yes its called a Rotor or Rotator, just like people used to sometimes have on their TV antennas eons ago. And yes they still make TV antenna rotors that you can get away with on the smaller lightweight beams. So lets look at some examples of beams and discuss the concept of free space.

 

 

Lets look at these patterns again from how you see them in EZnec software. The pattern on the left is a 5/8 wave omni-direction antenna and the pattern on the right is a 4 element cubical quad beam. Notice the beam antenna is directing most of your transmitting energy and recieving energy in one direction. Notice the difference in forward Gain in those directions 11.6 dbi versus 3 !! Thats a 8.6 db gain difference, or about just about 3 "S" units on most CB radio meters and many amateur radios as well. More importantly notice the side of the Cubical Quad beam...a signal that would be to your side of this antenna would be -30 db down! In other words, you are not hearing him , and he is not hearing you at all! How about a guy directly behind you? He's about -25 db down in signal, in other words he barely hears you, and you probably don't hear him. You ONLY hear and transmit to the station to are trying to get in that direction, in this case to the right. Everybody else is gone. This means your normal noise level of "S" 5 on your 5/8 wave omni for example....is now ZERO !

What was that you said about Free Space? Since in the real world, every single installation of an antenna is different; height of antenna, length of coax, type of coax, location..etc.etc.etc. There has to be someway to rate antennas based on if Nothing was around it. Litterally nothing, as if the antenna was transmitting and receiving in outer space. No ground, no trees, no house Nothing. This in the software world is called Free Space, it is an accurate way of rating antennas without any outside influence. So all of the db gain figures mentioned on these pages unless noted, are measurements in free space. What are they rated against? Good question they are rated against a standard half wave length dipole. On 11 meters this dipole is about 18 feet long. 18 feet of wire fed in the center with coax on 11 meters, pretty simple huh? You should try it, it actually works very well. And you can go to Home Depot and get a whole roll of wire for $20 and you can build dozens of them! A vertically built 1/2 wave wire dipole will eat your Antron 99 for lunch! It will match you radio very well SWR wise.You can hang it in a tree higher then you ever could mount your Antron without a tower on your roof and no one will ever see it !! And only cost you less then $5 bucks easily. Still think the Antron 99 is cheap?? The normal dipole gain is 2.15 dbi. Whats with the letter i after the db gain figure? Is it rated against something else, since it has gain? Very observant of you, why Yes. Its rated against an imaginary antenna (uh Oh) called an isotropic antenna. Yeah, I know sounds weird, but they had to start somewhere with this db gain stuff. So when you see the i after the db in reference to gain, it means that antenna is rated against the isotropic antenna.

 

So this means I can trust every manufacturers db gain ratings? Never Never Never. Before I regurgitate what I have said elsewhere, to learn more about db gain and manufacturer claims, please see the HF Antenna Gain button below and click it.

 

 

What are some good beams to start with?

 

 

 

 

Ok, lets look at these contenders for your first beam:

 

The top right photo is of a well known 2 Element cb beam. Hmm the manufacturer claims 9db gain! Is this possible? Maybe 100' above salt water. Is this a good antenna and does it make sense? In my opinion NO. the db gain claims are wildly exaggerated with no reference to what they are being measured against. Claims like "Each set of vertical/horizontal elements is counted as 1 element - so a "3 element"
beam actually features 9 elements" NO its a 3 element beam Period. Don't try to confuse the uninformed cb'er. In my humble opinion stay away from this manufacturer. As well as the other manufacturer who makes slanted element beams that they try to confuse you as ground radials! And somehow it increases performance. It doesn't. Don't listen to forum trolls pretending to be experts, they are just that...unless your into fantasy shows like "keeping up with the Kardashians" or "Survivor" ...then by all means, sit down and enjoy the nonsense. But please don't listen.

 

The top center photo is of a Maco V quad, known in amateur circles as the Delta Loop. This antenna is horizontally polarized, unless you mount it sideways where it will be extremly unstable in any wind. By that alone, I don't like it. Does it have any gain. It does ! About 4.7 db gain. Is it worth the trouble of getting one and mounting it sideways? In my opinion NO, there are better choices out there. Even better Maco antenna choices. An ambitious design for cb radio, unfortunately its normally horizontally polarized where it will not work well with all your local cb friends, but will give you a boost as far as skip signals go.

 

The top right photo is of a Maco Y quad, actual not a quad at all, but thats another story. This is basically a two element Yagi using a quad type reflector. Maco has a whole group of antennas with "quad" reflectors, all trying to emulate the famous "Avanti Moonraker" antenna from the 1960's. Should you use a quad reflector instead of a normal yagi element? NO. Is the performance any better then a straight 2 element yagi? NO. Is the F/B front to back ratio much better? Not really. The best thing about this antenna versus the one above is that you get Vertical and Horizontal (dual) Polarization. The gain is a little better than the above antenna, but really not much, you'd never be able to tell. But I do like this antenna better then the above V quad.

 

The bottom Three Pictures: These three get my recommendations, because they offer significantly better performance then the above three antennas, and they are still lightweight, and to be honest...they just make more sense then any of the designs above.

 

Lower left bottom photo AAH, the venerable Avanti PDL II Quad. Extremely popular in the 1970's and for good reason. This was many amateur operators first Cubical Quad. Although not exactly a true Cubical Quad, it checks all of the bases as far as wire length and configuration. It will give you performance very close to a 3 element Yagi, shown on the next two bottom photos and takes up less space and has dual polarization. Its pretty light considering the elements are made of wire and not aluminum. It also can be rotated with a cheap TV rotor. Although I personally would recommend a Yaesu 450 rotor for the job. the TRUE DB GAIN is 7.4 dbi in Free Space! Not too shabby. At 30 feet of height its gain is 12.2 dbi !! @ 16 degrees. You do understand now that even the best omni-directionals can not come close to a simple lightweight 2 element quad beam. SO whats the issue? Well its no longer made, and you have to find it on CB forums or Ebay for sale. And your probably going to pay a pretty penny for it. Is it worth it? YES. Find one and buy it. OR:

 

Lower center bottom photo This is just a standard 3 element Yagi, made by Maco, Cushcraft, Hygain, etc. The elements are turned vertical for 11 meters. All three of the manufacturers products I recommend for this antenna. The Maco is a little lighter, so if your in an area that doesn't get severe winds you'll be fine with that. All three will use a gamma match to match it to your coax. The short boom length models (about 8 feet) come in at 8 dbi of gain! You can buy longer heavier 14 foot boom models that have slightly higher gain. You'll need a smaller amateur radio rotor to turn this, even the 8 foot boom model, such as a Yaesu 450 rotor.

 

Lower right bottom photo This is a Maco M103HV....meaning two 3 element beams, one turned for vertical polarization and one for horizontal on the same boom. Does it work? YES. Is it a good antenna? YES. Does it have any more gain then the antenna mentioned just above this? NO. Its good for all you cb friends because once again like the Avanti PDL2 quad, you have both vertical and polarization at your fingertips. And speaking of gain and polarizations, there is a difference between Vertical and Horizontal Gain, where you can read about when you press the "HF Antenna Gain" button below. You will also learn that most skip ( DX in the amateur world ) will be heard better using horizontal polarization. Most noise is vertically polarized. So using horizontal polarization with locals who also have horizontally polarized antennas will cut down on alot of noise. Again any Skip that comes in, will come in better because the local vertically polarized noise sources (including cb'ers you don't like) will be mostly eliminated. And you thought CB Radio was already noisy huh? When CB Radio was concieved 60 years ago, it was strickly used as a base to mobile communication format. It was quiet before the CB Craze came in the 1970's. Mobiles obviously had to have vertical antennas. So thats why most CB antennas use vertical polarization. Normal BS and hobby talk was prohibited early on in CB Radio as it was strickly used between base and mobile stations and strickly enforced! Yes, I personally was made aware of that myself by Big Brother!

 

 

So what's next?

 

Well once you get past all the snake-oil sales pitches of cb radios and cb radio antenna manufacturers. You will find that there are basically only two types of commercially made or personally made in my case Beam Antennas. They are the Yagi and the Cubical Quad. Both are good. One offers simple screw-together convenience in most cases (the Yagi), while the other requires some manual tuning to maximize the performance, which in the end will be much better (the Cubical Quad).

 

 

What about the Moonraker you mentioned? I know I'll get emails about his antenna, so lets answer it now. The Moonraker is a 3 element yagi antenna, PLUS it is using a quad reflector in the back to supposedly provide a better front to back ratio. For 4 elements total on a 16 foot boom. Does it work YES. is it good? Not Bad, Decent....BUT...this antenna was made 55 years ago. Nobody had a computer, not even the manufacturer Avanti. Nowadays Yagi antennas as far as design and placement of the elements and matching techniques have been refined and better gain can be found with more recent antenna designs. The Moonraker made such an impression back in the day, because there was nothing to compare it to. Litterally no other big 4 element beams were sold in much quantity. So it got the top award back then as the biggest (they had a 6 element version too) and the baddest. But remember this is still 55 year old technology. Things have improved. A 4 element Yagi beam by any decent amateur radio manufacturer today will give you better performance and a 4 element Cubical Quad of the same boom length will run rings around it. Even on 10 meters..... where the Moonraker can be tuned to, NO knowledgable amateurs would even consider running one. Its not that it is bad, its not, but there are just much better Yagi's out there now. And if you ever entered into a 10 meter pileup with one, your going to be waiting a long time to get the station your trying to talk to on 10 meters. Even the BIG GUNS on Ch. 6, even if they have Moonrakers on their house and mucho illegal wattages (like multi-kilowatts), would quickly discover they are a small fish in the big Amateur Radio pond. Yes there are copy-cats of the Moonraker made by a couple of manufacturers. NO Don't do it. Unless you plan to stay on cb radio your entire life and talk to people you would never invite into your house! You know what I'm talking about people who your friends with on the radio but never actually become good friends because frankly you don't trust them, or maybe they are a little " off ". Listen if thats your thing, and you don't want to ever meet anyone in person and share experiences, laughs and maybe a few beers, then by all mean hang out on 11 meters until you croak with your fake friends. Doesn't that sound just like social media today ( that you hate )? Thats because back in the day 55 years ago...CB Radio was the social media. I urge you to become an amateur radio operator, you'll make real friends, learn real stuff about antennas and radios & radio propagation. You'll talk to people around the world easily, and see that most everyone is pretty nice to each other.

 

Ok, I came down off my high horse.....All I am saying its a big radio world out there, don't let 35 questions get in your way of exploring it.