The Better BNC for the Bucket Truck
For coax cable connections to analog cameras, our industry long ago standardized on the BNC style of connector. The BNC (Bayonet Neill–Concelman) was patented in 1951; consequently, it has been heavily used in analog CCTV, other video and 10BASE2 coax-connected Ethernet networks for decades. These connectors were and are manufactured by a wide variety of companies.
While this style of coax connector has certainly proved its worth, there are some issues with the basic BNC that should concern those security installation companies that want to limit future service calls caused by BNC connector failures or problems.
The typical BNC connector has the center conductor of the coax exposed at the mating point, allowing atmospheric elements such as moisture to create corrosion or oxidation on the copper or copper-clad steel conductor. The internal parts of this type of BNC are exposed to the elements, which can create internal corrosion issues. Over time and based on environmental conditions, this corrosion can cause erratic video signals and potential signal failure, which can result in device outage — which will generate a service call.
Basic BNC connectors are crimped onto the coax upon installation using a properly sized crimping tool. Once connected, any back-pulling on the coax cable will likely pull the cable end out of the connector, rendering it hors de combat and again creating a device/system failure.
What can compound the service call costs for installation companies are the locations such connectors are used. In many cases cameras are installed on the exteriors of buildings or in high elevations, requiring a lift or bucket truck to repair a failed BNC, multiplying the repair cost.
Also, when using standard BNCs, it is easy to misalign the center conductor when mating it to the female side, resulting in a bent center conductor. These conductors will likely need to be cut off and replaced because bending thin-gauge solid copper or metal conductors can cause cracks that may result in broken connectors when the BNC is exposed to temperature fluctuations.
A number of manufacturers such as Nitek, Altronix and others are producing media adapter sets that provide the transmission of 10/100 Ethernet and PoE power over new or existing coax cables. Knowledgeable security industry professionals are starting to use pre-installed coax cables in existing locations to connect IP cameras, access control devices, intercoms, etc. Using existing cables can slash installation time and cost, resulting in lower cost systems and upgrades for clients and more sales for the installation companies using these technologies.
So now the existing coax isn’t going to be used just to transmit 1 volt peak to peak analog video signals, but instead must be capable of transmitting high-bandwidth Ethernet and PoE. So those old crimp-on exposed center conductor BNCs need to be replaced.
IDEAL Industries is providing high-quality BNC connectors with their InSite connectors. If you pardon the pun, IDEAL is producing the “ideal” BNC connector for connection of coax cables to remote IP (or analog) devices.
The first issue addressed by the InSite connectors is weatherproof sealing. These connectors are installed using a compression tool that provides a 360-deg. compressed connection to the cable, making them virtually impossible to pull the cable out of the connector without using tools. At my ADI Expo presentations I have challenged many attendees to attempt to pull an InSite BNC off a coax cable; they tried their best, but it can’t be done with bare hands. These connectors will stay on for the life of the system.
The second issue that IDEAL’s InSite connectors address is the protection of the bare center conductor. If you look at the cut-away image on this page, you will see that once the cable is prepared, the center conductor slides into a gold-plated sleeve which completely covers the center conductor. This sleeve is the center pin that creates the connection to a camera or other device, and the gold plating is highly resistant to corrosion. And because the back of the connector is 360-deg. compressed, there is no possibility of moisture corroding the internal cable end.
Because the center pin goes into the sleeve, it is critical that the prepared cable end is fully inserted into the connector body. To provide visual verification that the cable is fully seated, the InSite connector has a clear window that allows technicians to verify that the cable is properly positioned in the connector before it is inserted into the compression tool and finished.
In terms of individual connector cost, the IDEAL InSite BNC connectors can be purchased for approximately $1.80 each, while old-style crimp connectors can be purchased for about $0.75 each. So spending an extra dollar for the highest quality connectors is a solid investment in your systems.
The next time you or your technicians are up on a bucket truck in the rain, replacing an old and bad BNC on a camera, do the right thing and use the highest quality connectors on service calls and new installations. It’s the connector that’s the final termination for making field devices such as cameras functional; why risk using old technology connector types when better and more robust connectors are available?