I use at times 10 awg stranded coated electrical wire and this is the band width I get 1:1 and to 1.5:1
1.0:1 SWR bandwidth of .470 MHz
1.5:1 SWR
Bandwidth of 3.350 MHz
1.0:1 SWR bandwidth of .470 MHz
1.5:1 SWR
Bandwidth of 3.350 MHz
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A Dipole for your CB Base Station?
- Thread starter Robb
- Start date
I use a dipole but I was 18 before I got into CB and I am really into mechanical, electrical, chemical understanding of everything I eat, drink, use, play with or need. In less then 6 months time after getting a CB I was building my own antenna's and other gear. Also I was around a lot of special forces personnel and even the Army Ranger's had a book on how to construct antenna's for field use and it was full of dipole designs.
The problem was that pre-1980's a lot of CB'er built dipole antena's and beer can antenna's etc....The 1980's had so much prosperity that a lot of people moved away from self sufficient means and moved into a world where you bought " the best most advanced gear". People had so much extra income that all kinds of people started manufacturing all kinds of things so now you could buy 10-20 different antenna from all kinds of different companies.we do not have People stoped making their own gear and just started buying their gear. We saw the same thing happen in food all of a sudden you could buy all these boxed cake, cookie and other baked good mix's where before all men and women had to buy the raw ingredients, find a recipe and make their own stuff from scratch.
So today we have a lot less variety in many area's of out lives. For instance the number of companies making CB radios has dropped a lot. The number of domestic instrument manufactures has likewise dropped. So as variety drops and prices climb compared to the cost of living you see a return to more self made things. The internet has made it easy to find information on constructing how built antenna's and we are seeing a return to people making more of their own things from raw materials again.
I think more and more people are starting to see that what you can buy is not always better than what you can make. Looking better does not equal better performance.
I used a 102 inch whip for almost 10 years and when I tried Firestick, K40, Wilson 5000 antenna's I was disappointed because none of them matched the performance I had been getting from a cheap RadioShack 102 inch SS whip from the 1990's. They cost more and where prettier but that was it.
So when I decided to get back into 2way radio I was not going to drop big money on a Imax2000 or Laser 500 Beams. In fact I found the the wire and PVC I used in my garage. I had to buy the connectors. I had to buy the raw materials to make my 1:1 Balun. I have less then $20 into my 11 meter dipole and that is counting the cost of the materials for the dipole and the balun. It functions as well as other peoples A99 or Imax 2000. My dipole is in my attic so it is not in the weather and it is the ultimate in stealth!
My dipole is not going to replace a nice set of beams but it is at least as good as omni-direction ground plane! I have owned a A99 and built beams in the past.
Any time you have differing polarity then the stations you are talking to you will have some loss. You can run a dipole vertically it is just not practical for most of us. That said few mobiles have truly vertical polarity it is almost always some compromise.
If you do not need a 1:1 Balun and had to purchase your dipole you can find pre-made 11 meter dipoles as cheap as $16 on ebay. They are not quite as pretty and sophisticated as what you can build for yourself but $16 is far cheaper then any other base station antenna.
If you talk a lot of skip and are into DX'ing t dipole is about as good as it get's!
The problem was that pre-1980's a lot of CB'er built dipole antena's and beer can antenna's etc....The 1980's had so much prosperity that a lot of people moved away from self sufficient means and moved into a world where you bought " the best most advanced gear". People had so much extra income that all kinds of people started manufacturing all kinds of things so now you could buy 10-20 different antenna from all kinds of different companies.we do not have People stoped making their own gear and just started buying their gear. We saw the same thing happen in food all of a sudden you could buy all these boxed cake, cookie and other baked good mix's where before all men and women had to buy the raw ingredients, find a recipe and make their own stuff from scratch.
So today we have a lot less variety in many area's of out lives. For instance the number of companies making CB radios has dropped a lot. The number of domestic instrument manufactures has likewise dropped. So as variety drops and prices climb compared to the cost of living you see a return to more self made things. The internet has made it easy to find information on constructing how built antenna's and we are seeing a return to people making more of their own things from raw materials again.
I think more and more people are starting to see that what you can buy is not always better than what you can make. Looking better does not equal better performance.
I used a 102 inch whip for almost 10 years and when I tried Firestick, K40, Wilson 5000 antenna's I was disappointed because none of them matched the performance I had been getting from a cheap RadioShack 102 inch SS whip from the 1990's. They cost more and where prettier but that was it.
So when I decided to get back into 2way radio I was not going to drop big money on a Imax2000 or Laser 500 Beams. In fact I found the the wire and PVC I used in my garage. I had to buy the connectors. I had to buy the raw materials to make my 1:1 Balun. I have less then $20 into my 11 meter dipole and that is counting the cost of the materials for the dipole and the balun. It functions as well as other peoples A99 or Imax 2000. My dipole is in my attic so it is not in the weather and it is the ultimate in stealth!
My dipole is not going to replace a nice set of beams but it is at least as good as omni-direction ground plane! I have owned a A99 and built beams in the past.
Any time you have differing polarity then the stations you are talking to you will have some loss. You can run a dipole vertically it is just not practical for most of us. That said few mobiles have truly vertical polarity it is almost always some compromise.
If you do not need a 1:1 Balun and had to purchase your dipole you can find pre-made 11 meter dipoles as cheap as $16 on ebay. They are not quite as pretty and sophisticated as what you can build for yourself but $16 is far cheaper then any other base station antenna.
If you talk a lot of skip and are into DX'ing t dipole is about as good as it get's!
We used to have "T Hunts" and I would make a lot of antenna for that. I also made direction finding gear and antenna for that as well. I would switch from my big whip to a hand held loop as I got closer to my target to help me locate them. Must of been an Army thing? LOL
CB has just hit an all time low is all. Their used to be plenty of talent and creativity on CB I think a lot of talent went to ham because of the decline of CB. The vulgarity and Jerry Springier like behavior on CB has driven a lot of talent away from CB towards ham!
CB has just hit an all time low is all. Their used to be plenty of talent and creativity on CB I think a lot of talent went to ham because of the decline of CB. The vulgarity and Jerry Springier like behavior on CB has driven a lot of talent away from CB towards ham!
Wha??!?!?
You couldn't have been on the CB radio lately - whatsoever!
As long as there has been skip in the last month alone, the channels have been a constant buzz to the point of over- crowding. People use adjactent channels when the parade of jackasses appear. In fact, at any given time during the day, the 11m bad smokes the 10m band for activity. For whatever reasons, the CB has a far more lax environment than the starchiness of 10m. Don't read me wrong, as I use a legal CB radio for 11m and use my Kenwood for 10m and do monitor them constantly, every day, every week, and every month, for the last several years.
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Getting back to the topic...is it correct to assume that I can use 2 off shelve antenna (like a firestick) and run the top and bottom as a vertical dipole? If so what is the advantage of using longer antennas like 4 ft vs 2 ft pairs? Finally, how much signal will be lost if I mount it inside a building. I may be forced to mount inside a warehouse. The communication will be for local use only. Thanks in advance.
Yes
Individual element length matters. With a center fed dipole you have two separate elements. In the case of 2 foot antennas elements they are both elements that will perform very poorly. An end fed four foot antenna, however, will require something to act as its other element, typically we use a groundplane, or some amount of metal under the antenna. A car's roof, or four radials pointing outwards is a good example of this groundplane. A single 4 foot antenna with no groundplane underneeth it will not tune or function well.
A note here, in either case, length matters, so make the antenna as long as you can. I would suggest a minimum of two 4 foot lengths for a center fed antenna, and would highly recommend pushing for two 5 foot lengths if possible. These are right in the length range where small length changes really begin to add up.
This depends on what the building is made out of. A metal building will block pretty much all of the signal, a wooden building will block next to none. Other materials will be typically in between these two extremes.
The DB
Sry about the double post....but
I've read that using two 5 ft poles will get 5/8 wave. And also 5/8 wave doesn't provide any noticeable difference than 1/4 wave, Is this true? If I used a 5 ft fiberglass antenna it will come to 1/4 wave since it's not the length of the pole but the length of the coil wrapped around them?
Ultimately, I guess the real question is will a center fed vertical dipole do any better than a regular 1/4 wave wipe from inside a structure.
I did the CB thing late 70's and early 80's and now that I'm much older, I'm just trying have some fun again.
I've read that using two 5 ft poles will get 5/8 wave. And also 5/8 wave doesn't provide any noticeable difference than 1/4 wave, Is this true? If I used a 5 ft fiberglass antenna it will come to 1/4 wave since it's not the length of the pole but the length of the coil wrapped around them?
Ultimately, I guess the real question is will a center fed vertical dipole do any better than a regular 1/4 wave wipe from inside a structure.
I did the CB thing late 70's and early 80's and now that I'm much older, I'm just trying have some fun again.
Two 5 foot elements will not get you anything like 5/8 wavelengths. 5/8 wavelength antennas are in the range of 22 feet long, and no matter what you do, short of mounting it higher, 10 feet or so of antenna is not anything like a 5/8 wavelength antenna.
Also, you got your quarter wavelength off as well. A quarter wavelength antenna for CB is between 8.5 and 9 feet long. A five foot antenna is a shortened quarter wavelength antenna, and will not perform as well as a full length quarter wavelength antenna. As a matter of fact, the 5 foot length is right about where performance begins to drop off very quickly. You are working with a compromise length from the start, which is why longer is highly recommended here...
Some mobile manufacturers, including Firestik, claim their mobile 5 foot antennas are 5/8 wavelength antennas. This is nothing but marketing. Those antennas do not perform anything like true 5/8 wavelength antennas, and instead perform like what they are, shortened quarter wavelength antennas.
If you are looking at actual quarter wavelength antennas alongside 5/8 wavelength antennas, and you have the same tip height, their performance will be similar. There are cases when some shorter antennas at the same tip height will actually outperform the longer antennas (sacrilege to many I know, but true none the less), those cases, however, are limited. In the case of using 5 foot antennas as elements, I highly doubt that will happen.
The DB
So, if I understand you correctly, my best bet is to use 2 102" whips for the vertical elements to get me 1/4 wave and stay away from using anything shorter?
I live about 3.5 miles away from work and mounting an antenna outside isn't allowed at work. Thus I'm looking for good solution that will be able to give the range I need.
Depending on the exact frequency, 102 inches IS 1/4 wavelength on 11 meters. Use 234/f for 1/4 wave; 468/f for 1/2 wave.
If you're serious about a center-fed vertical dipole, remember that without something like Hustler uses in their mobile antennas ("Resonators"), it's going to be ~18 feet from end to end, and you'll have to bring the coax straight away from the antenna for as far as possible (but at least ~18 feet). You might be better off with a plain 1/4 wave ground plane.
And the brick and concrete building -- does it have rebar in the walls? HVAC ducting, lighting and piping? You'll want to stay as far as possible from them.
If you're serious about a center-fed vertical dipole, remember that without something like Hustler uses in their mobile antennas ("Resonators"), it's going to be ~18 feet from end to end, and you'll have to bring the coax straight away from the antenna for as far as possible (but at least ~18 feet). You might be better off with a plain 1/4 wave ground plane.
And the brick and concrete building -- does it have rebar in the walls? HVAC ducting, lighting and piping? You'll want to stay as far as possible from them.
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Any idea how this vertical dipole plan might actually work?
http://www.instructables.com/id/Simple-CB-base-station-antenna/
I'm considering trying to build one of these this weekend for the CB base station. Does anyone have any opinions? I'm assuming if I only go 20 feet tall, that should leave the lower element about 11 feet off the ground, and the tip of the top element of wire approximately 29 feet off the ground. I guess I'll try to attach the base of the pvc mast to the side of my deck or to the side of my house, but the roof is only about 9 feet off the ground, so there wouldn't be a lot of support past that.
http://www.instructables.com/id/Simple-CB-base-station-antenna/
I'm considering trying to build one of these this weekend for the CB base station. Does anyone have any opinions? I'm assuming if I only go 20 feet tall, that should leave the lower element about 11 feet off the ground, and the tip of the top element of wire approximately 29 feet off the ground. I guess I'll try to attach the base of the pvc mast to the side of my deck or to the side of my house, but the roof is only about 9 feet off the ground, so there wouldn't be a lot of support past that.
Try a t2lt vertical dipole much simpler. coax is at one end, so you dont have the messy feedpoint half way up like the one in that article. Electrically the same, and you can use the same conduit and hardware.if you have already purchased it. And have a look at the first half of this thread.
http://www.worldwidedx.com/threads/homebrew-t2lt-dipole-and-3el-skypper-beam.181876/
Will work as good or most likely better than a A99 vertical.
http://www.worldwidedx.com/threads/homebrew-t2lt-dipole-and-3el-skypper-beam.181876/
Will work as good or most likely better than a A99 vertical.
Rob. Before i purchased and installed my a99 i used a center feed 11 meter dipole.
I was not yet using my Madison as I'd been off the air for almost 30 years and was stuck in past. Back then it was plate modulated AM local rag chew only.
When I decided to get a station together and wanted a simple low cost set up because I wasn't sure if I was going to enjoy it for long and even knew if there were locals to contact.
I purchesed an 11 meter dipole from an eBay seller who made and sold dipoles from 10 through 180 meters.. All of his dipoles looked well made and fairly pricred.
I never installed one and asked many questions to members of this site. After taking everryones advice into consideration i decided to go with the inverted V as i wss advised it would work well for local and skip.
When It came time to install no cutting or folding over ends it worked great for local and dx with a 1.1:1 right out of the box. I was only abel to get the feed center about 20' off the ground and was suprised at the great dx an local contacts not to mention the nice recive . Now that I mostly operate skip on ssb I'm concidering putting it back up in a horizontal configuratio manly for skip as I've since learned this is the ideal configuration for a dipole when dxing. It would also be nice to have two antennas to switch between. A dedicated ground wave and skip antenna would be nice.
The link below is the one i purchased from the seller and builder iI hope if someone looking for a wire dipole that comes ready to go with nothing to do but install it checks him out. Sorry I tried to share the ebays. dipoles for sale but i seem to be having a problem. .QUOTE="Robb, post: 126700, member: 8446"]While looking for an antenna for my new Ham rig, I was looking at dipoles. I was looking on the Radiowavz website for a Windom-design 10-40 meter dipole antenna, and noticed that they had a page that had dipoles for CB/11 meters too.
C.B. / 11 Meter
I've never known anyone to have or use a dipole on CB in all of the time that I was on CB years ago. I'm not sure that any of you have used one - or still do. The boast of the dipole for CB is the same as it is for Hams; low noise due to horizontal polarity, high power capacity, stealthy, and easy to tune and upkeep. There are rules that one must use for installation; but not beyond the scope of anyone. SO; does anyone use a dipole - or have you used one in the past? Tell me all about it, if you would.
Thanks![/QUOTE]
I was not yet using my Madison as I'd been off the air for almost 30 years and was stuck in past. Back then it was plate modulated AM local rag chew only.
When I decided to get a station together and wanted a simple low cost set up because I wasn't sure if I was going to enjoy it for long and even knew if there were locals to contact.
I purchesed an 11 meter dipole from an eBay seller who made and sold dipoles from 10 through 180 meters.. All of his dipoles looked well made and fairly pricred.
I never installed one and asked many questions to members of this site. After taking everryones advice into consideration i decided to go with the inverted V as i wss advised it would work well for local and skip.
When It came time to install no cutting or folding over ends it worked great for local and dx with a 1.1:1 right out of the box. I was only abel to get the feed center about 20' off the ground and was suprised at the great dx an local contacts not to mention the nice recive . Now that I mostly operate skip on ssb I'm concidering putting it back up in a horizontal configuratio manly for skip as I've since learned this is the ideal configuration for a dipole when dxing. It would also be nice to have two antennas to switch between. A dedicated ground wave and skip antenna would be nice.
The link below is the one i purchased from the seller and builder iI hope if someone looking for a wire dipole that comes ready to go with nothing to do but install it checks him out. Sorry I tried to share the ebays. dipoles for sale but i seem to be having a problem. .QUOTE="Robb, post: 126700, member: 8446"]While looking for an antenna for my new Ham rig, I was looking at dipoles. I was looking on the Radiowavz website for a Windom-design 10-40 meter dipole antenna, and noticed that they had a page that had dipoles for CB/11 meters too.
C.B. / 11 Meter
I've never known anyone to have or use a dipole on CB in all of the time that I was on CB years ago. I'm not sure that any of you have used one - or still do. The boast of the dipole for CB is the same as it is for Hams; low noise due to horizontal polarity, high power capacity, stealthy, and easy to tune and upkeep. There are rules that one must use for installation; but not beyond the scope of anyone. SO; does anyone use a dipole - or have you used one in the past? Tell me all about it, if you would.
Thanks![/QUOTE]
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