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#11
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![]() Everyone makes fun of newbies buying ready-built dipoles on eBay, but nobody can direct you to where to buy baluns? Searched hi and lo online, and what I found, was more expensive than buying a ready-made dipole! I'd like to buy a balun, and attach my own cut-to-length wire, but can't find cheap baluns ANYWHERE. Where are you Elmers buying your baluns? Every major amateur radio dealer I have bought from had baluns in their inventory, Ham Radio Outlet and Amateur Electronic Supply, to name two. However, you might find a wider selection from http://www.radioworks.com Ed K7AAT |
#12
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On Wed, 27 Aug 2008 13:17:39 -0700 (PDT), dbc254
wrote: Where are you Elmers buying your baluns? I build my own. Some reading material: http://www.dxzone.com/catalog/Antennas/Baluns/ However, if you wanna stimulate the economy, there are 7 commercial balun reviews on eHam: http://www.eham.net/reviews/products/1 -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
#13
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![]() "dbc254" wrote in message ... Everyone makes fun of newbies buying ready-built dipoles on eBay, but nobody can direct you to where to buy baluns? Searched hi and lo online, and what I found, was more expensive than buying a ready-made dipole! I'd like to buy a balun, and attach my own cut-to-length wire, but can't find cheap baluns ANYWHERE. Where are you Elmers buying your baluns? I don't bother with them. The ionosphere goofs up my pattern anyway. |
#14
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dbc254 wrote in news:110c0833-aa68-4266-b599-
: Everyone makes fun of newbies buying ready-built dipoles on eBay, but nobody can direct you to where to buy baluns? Searched hi and lo online, and what I found, was more expensive than buying a ready-made dipole! I'd like to buy a balun, and attach my own cut-to-length wire, but can't find cheap baluns ANYWHERE. Where are you Elmers buying your baluns? I think you haven't tried very hard. No endorsement: http://www.thewireman.com/baluns.html The above will have components you can use to make your own... a real learning exercise. dxengineering.com Owen |
#15
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![]() "dbc254" wrote in message ... Everyone makes fun of newbies buying ready-built dipoles on eBay, but nobody can direct you to where to buy baluns? Searched hi and lo online, and what I found, was more expensive than buying a ready-made dipole! I'd like to buy a balun, and attach my own cut-to-length wire, but can't find cheap baluns ANYWHERE. Where are you Elmers buying your baluns? My last purchase was from HRO, about $25 for a 1:1 to use with a wire dipole. Go to www.hamradio.com, enter balun in the search box and step through the offerings with Adobe Reader. Many hams will recommend you try a home-made balun, multiple turns of coax cable wound neatly around a cylindrical form. Exact requirements and effectiveness may vary with frequency and the antenna as installed. You might want to look at http://www.qsl.net/ta1dx/amator/broadband_baluns.htm. (It bothered me to see the letter W used for "ohms" in two places. I didn't spot any other errors/typos but ...) Also: http://www.hamuniverse.com/balun.html (many pictures) |
#16
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Ralph Mowery wrote:
I don't see wasting time or money on a balun for just a simple dipole . Sure it may make the patern vary from the normal textbook, but who cares most of the time. Most people have to put the antenna up wherever they can and lots of time it is not in the desired direction anyway. Very often, those are the same people who complain of "poor conditions" and "noisy bands", and operate in constant fear of causing RFI. Many of these problems are simply due to common-mode feedline currents bringing RF back into the shack and coupling into the mains wiring. In other words, people with limited antenna opportunities are often the ones who need a balun - or more accurately, a common-mode choke - the MOST. The problems of desperate antenna locations cannot be entirely cured, but they *can* be improved. Almost always, feedline chokes and/or baluns will have a valuable part to play. NOw a beam or some other antenna design is differant. The largest difference is in the attitudes of the users. No matter what your antenna is, or where you're forced to install it, it all comes down to one simple question: do you want to give this antenna the best possible chance to work correctly... or not? -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek |
#17
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Many hams will recommend you try a home-made balun, multiple turns of coax
cable wound neatly around a cylindrical form. Exact requirements and effectiveness may vary with frequency and the antenna as installed. You might want to look at http://www.qsl.net/ta1dx/amator/broadband_baluns.htm. (It bothered me to see the letter W used for "ohms" in two places. I didn't spot any other errors/typos but ...) Also: http://www.hamuniverse.com/balun.html (many pictures) ================ Nice URL with excellent info tnx Frank GM0CSZ / KN6WH |
#18
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Highland Ham wrote:
Also: http://www.hamuniverse.com/balun.html (many pictures) ================ Nice URL with excellent info The problem with ugly baluns is their limited frequency ranges. In the following measurements, the choking impedance was over 1k ohms for only small ranges of frequencies, 19-29 MHz, 10-22 MHz, 16-25 MHz, 8-16 MHz, 5-8 MHz - frequency ranges of 2/1 or less. HF covers a 10/1 frequency range. http://www.k1ttt.net/technote/airbalun.html -- 73, Cecil http://www.w5dxp.com |
#19
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![]() "John Smith" wrote in message ... JB wrote: Regards, JS Half-a-Brain-McCain'n Insane; So Lawdy Mama, It Looks Like Obama! I thought as much-- Your problem is obvious. What? You think yours is hidden? :-| The Devil deceives many and jeers at the truth. But those who call on the Lord in prayer keep him at bay. The sun shines on the wicked and the righteous. |
#20
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Many hams will recommend you try a home-made balun, multiple turns of coax
cable wound neatly around a cylindrical form. Exact requirements and effectiveness may vary with frequency and the antenna as installed. I saw an interesting talk at a local ham-club, at which the presenter gave an explanation for one reason that the "effectiveness may vary" with these sorts of choke baluns. The common-mode impedance created by many such chokes is primarily inductive (below the choke's self-resonant frequency, at least). The impedance of the unwanted current path (e.g. from the antenna feedpoint, back along the outside of the feedline, to the transceiver chassis or to the point at which the coax is grounded) will depend on the frequency and the length of the coax. It'll have a resistive component (from loss resistance and from radiation resistance) and will usually have a reactive component as well... either inductive or capacitive. If the feedline-path reactance is inductive or near zero, all is well... the choke balun's inductive reactance will (if sufficiently high) block most current flow along this path. On the other hand, if the feedline-path reactance is capacitive, and happens to be close in absolute value to the inductive reactance of the choke... then you've got a series-resonant circuit. The two reactances will largely cancel, the choke will "vanish", and you can actually have more current flow back along the feedline than you would without the choke. If you change the length of the feedline, the choke's performance can get better, or worse. His prescription: if you want choking that's going to be effective at a wide range of frequencies and won't be sensitive to the feedline length, you need to use a choke which will introduce a significant amount of resistive loss into the choked path (but not, of course, into the differential path that feeds the antenna). The usual solution is a ferrite. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |