Notes On Using A 4-Channel Passive Video Balun

4 Port Passive Video Balun (Terminal Type), with Power, Monitor Side

First things first, what is a 4-channel passive video balun?

A 4-channel passive video balun is a specialized electrical transformer that converts differential electrical signals to unbalanced (also known as single-ended) electrical signals. A 4-channel passive video balun is used when dealing with radio frequencies. For example, when the length of the cable is too long, when it is unshielded or when it is mismatched in impedance, then there is a possibility of loss signal; this is where the 4-channel passive video balun comes in.

The majority of digital video security and surveillance cameras still use coaxial cable specifically the RG-59. The RG-59 is a shielded cable that has an impedance of 75 ohms and that has aluminum, mesh wires or even plastic sheath. These features prevent the loss of desired radio frequency in and prevent external noise from reaching the cable. Now, let’s talk about CAT5 or Ethernet cables. Ethernet cable has a twisted pair of wires that cancels out electromagnetic interference from external sources. It is also called UTP or short for Unshielded Twisted Pair cable because it contains no shield that prevents outside noise for radio frequency applications. Ethernet cables can also be used for video transmission lines for digital video security cameras, but it has an impedance of about 100 ohms. Since the camera is transmitting its video data at an impedance of 75 ohms and the DVR has to receive it at 75 ohms, then there is a clear mismatch between the Ethernet cable and everything else.

This is where a 4-channel passive video balun comes in. The video balun will correct the mismatch of ohms going to and from the cable; in addition, the balun may also correct for noise, white balance, and other video signal attributes. It also enables four different signals to be sent over one CAT5 cable that is up to 1200 feet in length. When using a 4-channel passive video balun, make sure to purchase two units. The first one converts the signal from BNC to CAT5 while the second video balun converts the CAT5 back to BNC so it can be used by the DVR.

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.

How To Wind a Video Balun

Winding a video balun is not as hard as it sounds. You can, in fact, use household tools to do so. In this article, we will share with you tips on how to wind a video balun. For this task, you will need a ruler, a wire stripper, the antenna cable to which you want to wind it, some electrical tape and of course, the video balun. You can purchase a video balun from your nearby electronics shop or hardware store. You can also get it from a video balun manufacturer like PIMFG.com.

First, using the wire stripper, strip half an inch of insulation off the ends of the two wires attached to the balun. Now, slit four inches in on the outer insulation at the end of the antenna’s cable. Pull the insulation back to expose the inside of the cable.

Next, push the wire mesh back until it goes back to the uncut insulation of the cable. Carefully twist the mesh between your fingers until you are able to form a rod. Again, using the wire stripper, strip half an inch off the end of the inner wire of the insulation. Now, wind one of the two exposed ends of the wires from the video balun around the rod mesh you created. Wrap a strip of electrical tape around the two wires. Finally, wrap strips of electrical tape along the length of the cable from where the insulation ends up to the back of the video balun.

For more tips on using a video balun, keep reading this blog.


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Fiber Optic Cables: The Different Types and How They Are Used

The technology that fiber optic cables bring used to be only a dream. Fiber optic cables can transmit data by means of light pulses instead of electricity currents. This technology has become extremely especially useful in the telecommunications industry because they have revolutionized how telephones and even the Internet work. Nowadays, even businesses and organizations utilize fiber optic cables for their ability to send data faster in a more cost-effective manner.

What are the different types of fiber optic cables being used today and what differentiates them from one another? We may have previously shared more information about this but consider this a refresher to give you a better understanding of the different fiber optic cables available in the industry today.

Fiber Optic Cable, LC to SC, Single Mode Simplex (9/125) - 2 Meter

1. Single-Mode Fiber Optic Cable – Because single-mode fiber optic cables can only transfer data in a single stream, these fiber connections are often used for longer cable runs. The single stream of data actually allows for faster data transmission as the single light pulse is capable of carrying a significant amount of bandwidth. In Internet usage, single-mode fiber optic cables are used for Ethernet connections that require data transmission over long distances.

10Gb Aqua (OM3) Fiber Optic Cable, LC to LC, Multimode Duplex (50/125) - 1 Meter

2. Multi-Mode Fiber Optic Cable – Contrary to the single-mode fiber optic cables, multi-mode optical cables are capable of data transmission through several different paths. The pulses of light emitted transmit data allowing faster travel over a single fiber optic line. The downside, however, is that although more data can be transmitted, multi-mode fiber optic cables have less bandwidth available. Because of this, they are often used for shorter distances of data transmission such as a Local Area Connection (LAN).

3. Plastic Fiber Optic Cables – Made of plastic rather than glass, plastic fiber optic cables are not really used to transmit data as they are less reliable than single-mode and multi-mode fiber optic cables that are made of glass. Plastic fiber optic cables are, instead, used for impressive light displays and other ornamental purposes. These are continuously being tested upon by technology specialists for their ease of installation and usage but so far, the results are inconclusive as to whether they can be a potential alternative to commonly used fiber optic cable connections.