Differentiating Passive from Active Video Baluns

Before we go discussing how to distinguish a passive from an active video balun, let’s have a refresher on what a video balun is. A video balun works by converting a balanced line to an unbalanced line and vice versa. The word “balun” is derived from two words = BAL (balance) + UN (unbalance). What makes a balanced line different from an unbalanced line is that it has two conductors and equal currents that run in opposite directions while an unbalanced line only has a single conductor and current that returns through a common ground.

Passive Video Balun (Terminal Type), Power Converted - Monitor Side

A video balun functions in pairs, as one of the pairs is responsible for converting a balanced line to an unbalanced line while the other half converts the signal back. Through video baluns, signals transmitted are stronger and interference is minimal, making it extremely useful for surveillance purposes.

Passive video baluns offer less interference and degradation is minimal, making radio frequency signals transmitted stronger than others. These types of video baluns are used for their capacity to boost signal strength, making transition from one system to another seamless and noise-free. Some of the most common cables we use are Cat5E and RG59 coaxial cables.

Active Video Balun, (Screw Type) Camera Side

RG59 coaxial cables are passive video baluns and are ideal for the digital video security industry. The only disadvantage to using RG59 coaxial cables is that they only have a working distance of 600 feet, whereas Cat5E cables’, another type of coaxial cables for passive video balun that is generally less expensive than RG59 cables, signals can be carried up to 1,000 to 2,000 feet. Installation of Cat5E cables is also easier. A single cable of Cat5E is equivalent to 4 RG59 cables for 4 security cameras alone.

Active video baluns, on the other hand, is different from passive video baluns because they operate through electricity. Power is needed to use active video baluns, which most use 12VDC. Active video baluns can boost signals up to 4,000-5000 feet.