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Does a resonant dipole need a balun?
Paul, a dipole does not *have* to have a balun. Having one may help prevent RF from coming down the line into the shack and may improve the radiation characteristics of the dipole, but I’ve run dipoles connected straight to coax without a problem. Put one up without a balun and see how it works for you.
Does a folded dipole need a balun?
Like the basic dipole, the folded dipole antenna is a balanced antenna, and needs to be fed with a balanced feeder. Unbalanced feeders can be used provided that a balun (unbalanced to balanced transformer) is used.
Do I need a balun for a Yagi?
You will need a 1:1 balun or choke at the feedpoint of a Yagi to ensure pattern symmetry and best long term results but why is this needed? Coax is a wonderful product. It’s invention has allowed the feeding of antennas through a manner of different substances, conditions and places a balanced feed line could not.
What is a choke balun?
Essentially, a choke balun is designed to “divorce” your antenna from the feed line. If your feed line is coaxial cable then you don’t want it to be part of your antenna. You want to be able to deliver all your power to the radiator itself, i.e. “the antenna”. A choke balun does this admirably.
What do you use to connect a balun to a dipole?
Shown here is a £37 box of tricks from LDG – It’s a simple 1:1 Balun used with a resonant dipole (or G5RV coax>ladder-line join). Look how simple the device is: SO-239 connector, 2x 4mm terminals (cheap plastic thread!), some enamel copper wire and small toroid.
Which is the correct balun for an antenna tuner?
Based on the above, a 4:1 balun or any voltage-type balun is the wrong choice for use with antenna tuners in multi-band dipole systems. Most tuners use them because they are cheap, easy to build, and because almost everyone else uses them. Special DX Engineering Tuner Baluns For antenna tuners or systems with high SWR, we have a special balun.
Where is the Bal anced aerial on a dipole?
At the centre of a conventional Dipole – To interface the Bal anced Aerial to Un balanced Coax. Also at the junction between Balanced Feeder (ladder-line) and Coax – eg: G5RV. Many G5RVs simply offer a plastic SO239 adaptor which the ladder-line directly connects to.
How does load impedance affect a voltage balun?
Unlike a 1:1 ratio current balun, a voltage balun will always magnetize its core in direct proportion to load voltages. In a voltage balun, load impedance directly affects core heating and flux density.