What is the Correct length of antenna used for these frequencies Can an Antron 99 be cut or trimmed to cover this portion. I am curious to how much work is involved with this or if its better to eventually buy a new antenna to cover this.
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Antenna to cover 3.843.00 - 3.898.00 - 3.913.00
- Thread starter TonyV225
- Start date
That Antron had better be made of rubber. A quarter wavelength on those freqs. is about 66 FEET long. I don't think you can streatch it that long. :tongue:
The Antron 99 is a 10,11 and 12(with tuner) meter 24 to 30 mhz antenna.As far as I know it will not tune to the 80 meter band.There are several dipole antennas that you can buy fairly cheaply that will cover that band with little or no trouble at all.
I just took a look at an A.E.S cataloge dated from last year,on one page I found 4 dipole antennas that were under 50$. Hope that helps
I just took a look at an A.E.S cataloge dated from last year,on one page I found 4 dipole antennas that were under 50$. Hope that helps
I made this one-
http://www.w8ji.com/windom_off_center_fed.htm
137 ft. I found by watching my field strength meter that the coax was radiating so I made a Balun using a 3 litre soda bottle and wound around 21 ft of coax around it and it is totally gone ! similar to the one below-
Other styles can be found below-
http://www.hamuniverse.com/balun.html
I made the antenna out of clothes line . I bought 2 100ft rolls at $3.00 a roll. The speaker wire binding post was just under $3.00. So I have around $9.00 in the antenna. I use it for 80 and 40 and can tune 20 and 10 meters and it works excellent ! My tuner tunes my aluminum groundplane for 20 meters and up . I have it going out of my attic to a tree which I tied a piece of cloth line and a big steel nut that I used to throw up in the tree branches. The ground side of the antenna is in the attic. That way the coax drops out of the attic vent down to my radio room window.
http://www.w8ji.com/windom_off_center_fed.htm
137 ft. I found by watching my field strength meter that the coax was radiating so I made a Balun using a 3 litre soda bottle and wound around 21 ft of coax around it and it is totally gone ! similar to the one below-
Other styles can be found below-
http://www.hamuniverse.com/balun.html
I made the antenna out of clothes line . I bought 2 100ft rolls at $3.00 a roll. The speaker wire binding post was just under $3.00. So I have around $9.00 in the antenna. I use it for 80 and 40 and can tune 20 and 10 meters and it works excellent ! My tuner tunes my aluminum groundplane for 20 meters and up . I have it going out of my attic to a tree which I tied a piece of cloth line and a big steel nut that I used to throw up in the tree branches. The ground side of the antenna is in the attic. That way the coax drops out of the attic vent down to my radio room window.
You don't want to "eventually" get a new antenna for 75 meters. If you're going to operate there, you need an antenna for that band. Being a ham, you should know the formula for a dipole, so whatever you do, don't "buy" one. Build it from scratch. Trim it for the frequency you want and feed it directly with coax. I've never used a dipole that truly needed a balun.
By the way, why such a narrow range of frequencies? General class licensees have the full band.
I needed one with the offcenter Windom as my coax was radiating as in the artical below. I read that this can be a problem with using coax as a feed line for the Windom. It worked.-
"
In transmitting antennas, this is accomplished by presenting a high impedance (resistance), to RF currents flowing outside the coax shield. This forces currents in each side of a driven elements to be equal. This is especially important in beam antennas because it prevents distortion of the beam's pattern caused by unequal currents in the driver(s). In a simple dipole, the balun (choke), assuresthat the dipole, and not the feed line, is doing the radiating!
When you connect center fed antennas, like dipoles, V's, triangles, yagis, rhombics, loops and so on, to coaxial cable, unless care is taken, it is not difficult to end up with feeder radiation. Not only can the loss in power be quite significant, but the radiation characteristics of the antenna system will also be seriously compromised.
In laymen's terms, it won't be what you are expecting from the pattern of your antenna.
As the feedline becomes part of the antenna, currents can flow from the line into the mains and on TV cables, metal masts and yagi booms, causing a variety of EMI problems that can be very difficult to trace. Frequently these problems are simply due to unbalance - and the solution is the humble air choke.
If an antenna system is fed at center with a parallel conductor line (provided that correct installation procedures are followed) balance will be maintained, USING A BALUN, with currents in equal and opposite phase canceling each other out.
When the connection is to a coaxial cable, WITHOUT A BALUN, this cannot occur because currents flowing inside the cable from the connection to the inner conductor are separated from those flowing on the outside from the connection to the shield, and the result is unbalance causing feeder radiation. However, if the two electrical circuit elements (antenna and coaxial cable) are coupled using a balan, balance will be maintained."
http://www.hamuniverse.com/balun.html
[/SIZE][/SIZE]
"
[SIZE=-1][SIZE=-1]A balun's purpose is to allow connecting a BAL[/SIZE][/SIZE]
[SIZE=-1][SIZE=-1]anced load (e.g., a dipole or driven element) to an UN[/SIZE][/SIZE][SIZE=-1][SIZE=-1]balanced line such as coax which is not balanced, thus the name, Balun. The 1:1 choke "balun" is not actually a balun. It's function is to help eliminate rf currents from flowing on the outside of coaxial cable using the principle of choke action.In transmitting antennas, this is accomplished by presenting a high impedance (resistance), to RF currents flowing outside the coax shield. This forces currents in each side of a driven elements to be equal. This is especially important in beam antennas because it prevents distortion of the beam's pattern caused by unequal currents in the driver(s). In a simple dipole, the balun (choke), assuresthat the dipole, and not the feed line, is doing the radiating!
When you connect center fed antennas, like dipoles, V's, triangles, yagis, rhombics, loops and so on, to coaxial cable, unless care is taken, it is not difficult to end up with feeder radiation. Not only can the loss in power be quite significant, but the radiation characteristics of the antenna system will also be seriously compromised.
In laymen's terms, it won't be what you are expecting from the pattern of your antenna.
As the feedline becomes part of the antenna, currents can flow from the line into the mains and on TV cables, metal masts and yagi booms, causing a variety of EMI problems that can be very difficult to trace. Frequently these problems are simply due to unbalance - and the solution is the humble air choke.
If an antenna system is fed at center with a parallel conductor line (provided that correct installation procedures are followed) balance will be maintained, USING A BALUN, with currents in equal and opposite phase canceling each other out.
When the connection is to a coaxial cable, WITHOUT A BALUN, this cannot occur because currents flowing inside the cable from the connection to the inner conductor are separated from those flowing on the outside from the connection to the shield, and the result is unbalance causing feeder radiation. However, if the two electrical circuit elements (antenna and coaxial cable) are coupled using a balan, balance will be maintained."
http://www.hamuniverse.com/balun.html
[/SIZE][/SIZE]
Calculate the frequency/length of antennas Here:http://www.crompton.com/wa3dsp/hamradio/antcalc.html
Thanks to WA3DSP for providing the Page.
73
Jeff
Thanks to WA3DSP for providing the Page.
73
Jeff
Thanks People I do have A G5RV new never used I thought about this after I asked my stupid question and realized it made no sence and then thought about the dipole inverted V ETC Sorry for the crazy question. BEETLE I am not a Ham yet there is another classroom and testing coming up I am just thinking about all this so in spring when my Tower goes up at the new house here I have an idea what to do sorry if this question offended you but I wasnt thinking until I after I asked it and then later thought about it its impossible to st up at that length when the length isnt even there to work with. Anyways Jeff I was thinking for other bands Cushcraft antenna but like anything else I here some say nice antennas and some say stay away. What are your thoughts on it or can you give me some ideas on what would be my best bet for covering on good portion of what I would have privs to use? I am gonna do tech and then I will do general 2 months after thats what my goal is thats where most of my friends are all sitting at and they all did what I want to do I would be happy with General Privs I know that G5RV is a great antenna and Im glad I have a few achers here to use LOL
I liked QRN's responce
" That Antron had better be made of rubber. A quarter wavelength on those freqs. is about 66 FEET long. I don't think you can streatch it that long. "
" That Antron had better be made of rubber. A quarter wavelength on those freqs. is about 66 FEET long. I don't think you can streatch it that long. "
There are several in my area that run the G5 dipole and everyone really likes it that I talk to.They all have informed me that they get good over all reports on air. So when I finally do upgrade my ham ticket I will be getting one of those for my shack.What I like about it is the fairly low cost,that is always a plus for me personally
Now for the Virtical low band antenna.The Cushcraft from what I am hearing is a good one to use.I hear of a few around here that are running it and they do like it.Most of the low band virticals usually work about the same performance wise from what I am reading and hearing so I would figure it is pretty well what brand you like and just how much you are wanting to spend
My 2 cents worth
Now for the Virtical low band antenna.The Cushcraft from what I am hearing is a good one to use.I hear of a few around here that are running it and they do like it.Most of the low band virticals usually work about the same performance wise from what I am reading and hearing so I would figure it is pretty well what brand you like and just how much you are wanting to spend
My 2 cents worth
TonyV225, Rather than calling your question 'stupid', I'd say it was 'uninformed'. The only really 'stupid' one is the one not asked. How'z that for 'politically correct'? Some generalizations; Bigger antennas are easier to use than smaller ones, they aren't quite as 'picky' when used where they were not designed to go. That doesn't mean that they will always work well, or even work, but at least there's a possibility of it. [Harmonically resonant, sort of. This is one area where a 'robust' tuner comes in handy.] There will be losses. In most cases, those losses just don't make much difference, sort of. Especially if it means getting on the air or not getting on the air at all. I have this aversion to 'buying' antennas. It's just a lot more fun to have that 'saved' money for other things. And not having any high support structures such as a tower, getting an antenna high enough to not catch under my nose is easier with 'wire' than with other thingys. Having several dipoles connected to the same feed point and feed line works. Several names for that sort of thingy, ugly being one of them, but who cares, it works just fine which is the point of the whole thing. A 500 foot spool of wire goes a looong way! Can't string up a lot of wire? How about feeding the @#$ tower? That can work too. Sometimes, even better than what you'd think. Hey, them commercial stations do it, so why not? Sound like I like wire antennas? I do. They're cheap, easy, and work fine. Are they the 'best' thingys around? Not in all cases, but they are in a lot of cases. Did I mention them being cheap?? - 'Doc
Tony - the question didn't "offend" me, and I hope I didn't offend you. Even as someone who's studying for his ham ticket, you should know how to figure the size of a dipole, and realize that the closer the actual antenna dimensions are to this length, the easier the antenna will be to work with.
The G5RV is a popular antenna, but a lot of people seem to think it's a lot more than it really is: a 20 meter antenna that sort of works on some other bands. It won't work well at all on the WARC bands (30/17/12M), and will require a tuner for most of the other bands.
Sonwatcher: I know the purpose of a balun. I've built my own for antennas that truly required them, and I've used commercial baluns at other times. Still, a balanced dipole fed directly with unbalanced line (coax) WILL radiate, and quite efficiently. I have 178 countries confirmed on 80 meters, using 100 watts and an 80 meter dipole fed directly with RG-213. The radiation pattern is probably not exactly as shown in an antenna manual, but so what? Results trumps theory in many cases, including whether baluns are absolutely necessary at all times.
The G5RV is a popular antenna, but a lot of people seem to think it's a lot more than it really is: a 20 meter antenna that sort of works on some other bands. It won't work well at all on the WARC bands (30/17/12M), and will require a tuner for most of the other bands.
Sonwatcher: I know the purpose of a balun. I've built my own for antennas that truly required them, and I've used commercial baluns at other times. Still, a balanced dipole fed directly with unbalanced line (coax) WILL radiate, and quite efficiently. I have 178 countries confirmed on 80 meters, using 100 watts and an 80 meter dipole fed directly with RG-213. The radiation pattern is probably not exactly as shown in an antenna manual, but so what? Results trumps theory in many cases, including whether baluns are absolutely necessary at all times.
Beetle,
I wasn't saying it wouldn't radiate correctly without a balun. My problem was I was getting RF from my feedline and the balun totally (air choke) took care of it.
I wasn't saying it wouldn't radiate correctly without a balun. My problem was I was getting RF from my feedline and the balun totally (air choke) took care of it.
I have a few Tuners and also 2 of the radios I own have tuners my FT990 and My TS-50 has a matching outboard auto tuner the AT-50 this is all such a different world its almost kind of scary well in a way. Ok thanks for the help and ideas.
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