Security camera networks require lots of cables. When laying
long runs of cables installers usually have a choice between using CAT5 cable or
coaxial cable. CAT5 cable is cheaper than coax cable, but has different
electrical and physical characteristics.
You can't just connect the wires - you'll lose signal
strength and picture quality. A video balun corrects this
problem by balancing impedance and other electrical
characteristics, which minimizes signal loss and noise.
It's important to use video baluns when sending video over
since the impedance specifications of Cat5, Cat5e and
Cat6 are 100 ohms. Video requires 75 ohm impedance and
you'll introduce artifacts to your video without a balun.