What is a balun box?

A balun /ˈbælʌn/ (from “balanced to unbalanced”, originally, but now dated from “balancing unit”) is an electrical device that allows balanced and unbalanced lines to be interfaced without disturbing the impedance arrangement of either line.

What is the purpose of a balun?

This transformer is known as a balun, and they are in operation in anything from telephone lines to transmitters. Baluns are used both to sort out the flow of AC signals and make the necessary impedance transformation between coaxial cable, which has a low impedance, and balanced loads, which have higher impedances.

What is a balun and how does it work?

A balun (balanced line to unbalanced line) is a device that transforms a balanced transmission line to an unbalanced transmission line. Baluns are hooked up to antenna systems to help electricity run smoothly from the ground to the device.

Do I need a balun to receive?

Yes, you do need a balun. A simple quarter-wave dipole is balanced, coax cable is not. Your problem now is that the outer of the coaxial cable is acting like part of the antenna, adding or subtracting from the signal as you move it around.

Does a balun reduce noise?

Whilst a balun is usually associated with reduced unwanted transmission line radiation (eg. from the feedline and power cord), a balun can also help minimise unwanted noise picked up by your feedline. There are many sources for design and construction of simple baluns on the internet.

How do I choose a balun?

Select a balun closest to the antenna feedpoint impedance (you’ll have to get this from textbooks or modeling), and use it at the feedpoint or where the feedline from the antenna ends. Be sure the feedline between the balun and antenna feedpoint matches the antenna impedance as closely as possible.

What is a 1 1 balun?

Key uses for the 1:1 current-balun: a) is to marginalize the “inverted-L current” in the transmission-line feeding a dipole-antenna. This will prevent a radiating Feedline and prevent distorting the antenna’s radiation pattern. There will be some flux in the core but it’ll be minor due to the small current causing it.

Why are the ham bands so noisy?

It comes mainly from noise from atmospheric discharges which are always taking place somewhere in the world and are propagated by the ionosphere. Both these sources sound like white noise There may also be local atmospheric static but this is usually not a serious problem in the UK.

Who is W8JI?

Tom Rauch, W8JI, is one of the most renowned antenna authorities of our times. He has an outstanding web site where he shares his knowledge with all of us who are willing to take the time and read it, AND he was the chief architect of the portfolio of Balun products sold by DX-Engineering in the states.

What are the types of balun?

The first thing to realize is that there are two types of baluns: Current Baluns and Voltage Baluns. The balun’s ratio is normally stated from balanced to unbalanced (just as the words appear in the acronym). A 4:1 balun has four times the balanced impedance as unbalanced impedance.

https://www.youtube.com/watch?v=u2bMcMnmbpE