How does a balun work?
Baluns are used to convert between "Balanced and Unbalanced" electrical signals.
Baluns work by transforming the original unbalanced (video/power/data/etc) signal to a balanced frequency used by a different cable, like CAT5 UTP. Not only does this reduce interference, but it also allows you to transmit a signal much longer than the original application would allow. Baluns are always utilized in pairs. One balun is needed to convert the original signal to a new frequency, and another balun is used at the other end to revert to the original frequency.
"Passive" Video Baluns do not require power, and can extend a signal up to 2000ft (B/W)
"Active" Video Baluns require power, but can extend a signal up to 8000ft (B/W)