Posts Tagged ‘ bnc connections ’

BNC Connections

Friday, July 8th, 2011

Probably the most common cable joiners in the digital video security systems industry are BNC connections.  BNC connectors are easy to use and ensure a sound, full contact connection.  BNC connections are different than most other single pair wire connectors  (such as RCA plugs, for example) plugs, becuase BNC connections are “locked” in place.  The following article is about the origin and use (including applications) of BNC Connections.

BNC is an acronym for this type of radio frequency connector.  The connector is designed for use with coaxial cable and is generally used for radio, television–including digital video camera security systems, and other radio-frequency applications.

BNC stands for Bayonet Neill-Concelman.  Bayonet (“B”) represents the the type of twist locking system that holds the connectors together.  Unlike RCA plugs that just push together can be subjected to accidental disconnection, BNC connections are locked together in the same twisting lock configuration as that of a gun bayonet.   Generally, BNCs do not become disconnected unless they are purposely untwisted from the locked connection.

The “N” and “C” in BNC stands for the first letters of the last names of the two men that invented the connector; Paul Neill and Carl Concelman.  However, origin for development lies with Octavio M. Salati, a graduate of the Moore School of Electrical Engineering (of the University of Pennsylvania).  In 1945 Salati filed for a patent for a coaxial cable connector that would minimize wave reflection and/or loss (one of the primary attributes of a BNC type connector).

Another feature of the BNC connection is that the connectors are available to match the impedance of the cable they are connecting.  Generally, there are two major types of BNC connections based on impedance, 50 and 75 ohm versions that are used today.

There are also many variations that originated from the BNC design.  These include the SR-50 and SR-75 Russian copies whose dimensions differ slightly from the BNC because of converting the measurements from English (Imperial) units to metric.  There is also a Threaded Niell Concelman or TNC connector that displays superior performance over a BNC for microwave applications.

The BNC connection consists of two separate pieces, the “female” and “male” ends.   These ends are firmly and permanently attached to the shielded coaxial cable.  The male end consists of a center (usually) solid copper core wire with the metal shield or mesh that surrounds the cable completing the single pair wire connection.  The male connector is pushed into the female connector and twisted, making the single pair connection and locking the connection at the same time.

There are also different types of BNC connections based on how the actual connector is attached to the cable or provides adaptation to a BNC connector.  Security Camera King offers a variety of BNC connectors on their on-line store catalog.  They may be found at or by clicking “Security Camera Accessories” the “Surveillance Camera Connectors” on the left hand side of the home page.

Security Camera King offers three different types of BNC connections base on how the connector attached to the cable it is attached to and not the actual connection between BNC pieces themselves.  In addition, more many connectors they offer a single unit price and a 100 unit price.

The first of three is the crimp-on connector.  This connector requires the use of a crimping tool to secure the banded necks of the BNC to the coaxial cable.  They are referred to in our catalog as “2 Piece Crimp-on BNC Connector).  These are fairly easy to work with, and when installed properly, including being crimped properly, these provide a fair to good connection.  This BNC requires the use of a special crimping tool.

The second is the twist-on connector.  They are referred to in the catalog as “BNC Connector Twist-On.”  This BNC connection is easy to install (just twist or screw on the cable ends) and requires no special tools.  These connectors hold fairly well and provide a fair to good connection.  Screwing the connectors onto the cable ends can actually be a little difficult though.

The third type is a compression connector.  They are referred in the catalog as BNC Compression Type Connector.”  These connectors require a compression crimping tool (also sold by Security Camera King) and provide an excellent connection and are easy to work with.

In addition to BNC connections, there are many other adaptor and connector types available for purchase on the Web page listed above.


Security Camera Monitor

Thursday, March 3rd, 2011

The security camera monitor is probably considered one of the most important components of a digital video security system.  Yet, it is not purchased as often as other components like cameras and Digital Video Recorders (DVRs) and today’s systems can actually run without one.  In fact, Security Camera King takes pride in offering a complete digital video security package that includes the cameras, cables, connectors, power supply, and DVR but no monitor.  Why is that?  Read on to find out why, and to learn some other interesting facts about the security camera monitor.

There are three types of security camera monitors based on how they are used.  The first is a set-up monitor.  This monitor is only used when the system is first installed or any future changes are made to the system.  It may come in a variety of styles and sizes.  Security Camera King offers, for example, our product number VX-WLCDM, a 2.5 inch LCD service monitor with a wrist strap.

Use this monitor to aim cameras, choose settings on the DVR, and check connections.  Once the system is set up or the changes are made, the monitor is usually disconnected from the system.

The second type of security camera monitor is called the “spot monitor.”  A spot monitor is usually a monitor that is connected to just one camera.  It allows the user to specifically monitor full-time that one area of the security system that the specific camera covers.  The monitor maybe located in close vicinity of the camera it is monitoring or may be located in another location, whichever is most appropriate for the user.

If the spot monitor is used on a “cabled” system, there must be a separate cable run to the spot monitor in addition to the DVR.  This is usually accomplished by adding a splitter to the cable at some point to create a feed to the spot monitor and another to the DVR input.

The third type of security camera monitor is the system or main monitor.  This monitor is generally connected to the DVR by one or more cables and displays the on-screen information of the cameras and the DVR.  Usually this monitor is bigger in size than a spot monitor so that it can accommodate the simultaneous displaying of all or groups of cameras in the system at the same time.

Security camera monitors are like televisions (or perhaps more like personal computer monitors) in composition.  There are basically two types of monitors that are used today, but generally there is only one type that is used the most often.  The two types based on composition are the CRT and LCD monitors.

The CRT or Cathode Ray Tube monitor is the oldest type.  As its name implies it consists of a Cathode Ray Tube that produces the picture.  The CRT monitor is bulkier, heavier, and produces a lower resolution picture than the LCD monitor; basically, its equivalent to the older models of televisions that also used a CRT.  These monitors are still used today, but usually in older systems or as spot monitors.

The LCD or Liquid Crystal Display security camera monitor is probably the single most popular monitor type in use today.  It is much lighter than the CRT, it uses less energy, and displays at a much higher resolution and color, capable of providing quality high definition displays.  These monitors were once limited in size, but as technology advances so do the available sizes.  Security Camera King offers monitors as large as 42 inches.

A monitor is required to initially set-up a system.  However, all systems do not necessarily have system monitors.  The reason for is because once the system is set up it can record and function automatically.  More often however, users have personal computer systems or older monitors from computer systems in which the system is outdated but the monitor is still useful.  Then again, many users opt to connect their systems to the Internet and use any computer system’s monitor or even a Smartphone instead.

One last note; if you are considering purchasing a security camera monitor, regardless of the type, make sure the monitor has the proper connection input type available.  Our DVRs have HDMI, VGA, and BNC connections to make connecting the monitor an easy process for you.  However, many monitors, especially those once used for computers, only have a VGA connection for example.  So be certain to make sure your monitors, camera and DVR display types, and connectors match.