Are you looking for a BNC cable? You can buy these cables in different lengths with pre-assembled connectors. In addition to cables with a connector on both sides, you can also buy various adapter cables, for example BNC to VGA, to tulip, to SDI, to UTP, to N connector, to SMA, or to F connector. If you want to make a BNC cable yourself, you can choose the classic screw connector or the much faster crimp connector. For the latter you will need a special crimping tool, which we also sell.
Best BNC Cables
What is a cable with BNC connector?
This connector was developed by Paul Neill working at the American Bell laboratories and Carl Concelman working at the American connector manufacturer Amphenol. Both had a lot of experience in developing connectors. Neil developed the N connector and Carl the C connector. BNC stands for Bayonet Neil Concelman. The connector is a high-frequency coaxial connector where the signal is enclosed between the center conductor and the sleeve of the coaxial connection. The plug is easy to connect to a chassis part due to its clever construction. The connector is plugged into the socket with the electrical contact for the outer jacket being made by spring blades in the plug. The center pin is clamped in a spring loaded sleeve in the BNC chassis part. Two short pins on the outside of the chassis engage in the recesses of the plug’s rotatable sleeve. This can be mechanically easily locked by turning the sleeve of the connector a quarter turn, after which it clicks into place. This connector is suitable for use with high-frequency signals up to approximately 4 Gigahertz (GHz) at a maximum voltage of 500 volts effective.
The BNC connector
The BNC connector is a popular high-frequency (HF) connector and is used in many different places. This includes measuring equipment such as an oscilloscope, professional audiovisual equipment and antenna connections to transmitting and receiving equipment. It is a coaxial connection that is mounted on a coaxial cable. Because mounting is a precision job that takes time, many people choose to buy a cable with pre-assembled BNC connectors. If you want to make your own cables because you install them through walls or in cable ducts, you can order loose BNC connectors and separate coaxial cable. You can order this per meter or per roll.
When ordering, pay attention to the correct characteristic impedance of a BNC cable. The characteristic impedance is the ratio of the voltage between the conductors and the current through the conductors of a BNC cable, when transporting an HF signal. The characteristic impedance is determined by the inductance and capacitance between the conductors, which in turn are determined by the construction of the coaxial cabling and connectors.
Characteristic impedance
One of the first important properties of a BNC cable is the characteristic impedance. In practice, 50 ohms is the most commonly used value. This value is mainly used for measuring equipment, transmitting and receiving equipment, surveillance cameras and many other applications.
A well-known 50 ohm version is the commonly used RG58U cable. If you want higher quality cabling with a lower signal loss, you can choose a different type of coax cable. A BNC cable with a characteristic impedance of 75 ohms is available especially for equipment that uses 75 ohm inputs and outputs. Both the coaxial cable and the BNC connector have a characteristic impedance of 75 ohms. An example is the RG59U cable.
When connecting video equipment in particular, pay attention to the characteristic impedance and use cabling with the impedance indicated on the equipment. If you use a cord with a different impedance, this can lead to signal losses due to a poor standing wave ratio and ghost images in the image. These effects will be particularly noticeable when using longer cables.
Other properties
Every cabling suffers from signal loss due to its ohmic resistance. Only part of the signal that enters a cable on one side arrives on the other side. This effect is called cable attenuation and is especially noticeable with longer cables. Cable attenuation is specified in dB per 100 meters of cabling. DB stands for “deci Bell” and is a logarithmic scale in which every 3 dB means a signal attenuation of half. With a 6 dB attenuation, only a quarter of the signal remains. The advantage of using dB is that the attenuation values of cables in series can easily be added together.
Because in recent years more and more sources of interference such as smartphones and Wifi Access points have been added, the problem of interference increasingly occurs in practice. In the event of interference, a signal in a coaxial cable from the outside is negatively affected by an HF signal from the outside. A notorious example is the influence of cable TV signals by 4G telephone signals. To counteract this interference, it is important to use a BNC cable with good shielding, for example a triple foil shield.
