A balun, if you really want to be precise, is a conversion device that turns a balanced signal into an unbalanced one or vice versa. What that means is that it converts between two types of electrical circuits: one that has two signals of opposite polarities and one that is just one signal and a ground.
The most common use of a balun for folks who read this blog is to convert from flat antenna lines (300 ohm impedance) to coaxial cable (75 ohm impedance.) Antennas themselves use 300 ohm wiring but coaxial cable is most commonly used to get antenna signals to the TV, providing better shielding and durability. A balun is used to convert the antenna’s signal into coaxial. Less commonly, another balun can be used at the television or audio receiver if that device has a 300 ohm connection point.
Baluns can also be used for network cabling if coaxial cable is used, so that the signal is converted to use the more traditional RJ45 connector. A similar product is used for video cameras that send digital data over coaxial cables but need to connect to a DVR requiring a pair of individual cables.
Terms like “balun” tend to grow in popularity and people don’t understand where they come from, so the term has come to mean any device for converting between two fairly different types of signals, for example from VGA to HDMI. While technically VGA and HDMI are both balanced signals, we don’t refer to the converter as a “balbal” partially because that’s a really stupid sounding word. The correct term for a wire that converts VGA to HDMI is a “dongle” (admittedly also a stupid-sounding word) but it’s ok to use the term “balun” here as well.
Solid Signal has a wide variety of baluns for all sorts of uses… shop now!