BNC connector
Encyclopedia
The BNC connector is a common type of RF connector
used for coaxial cable
. It is used with radio
, television
, and other radio-frequency
electronic
equipment, test instruments, video signals, and was once a popular computer network connector. BNC connectors are made to match the characteristic impedance
of cable at either 50 ohms or 75 ohms. It is usually applied for frequencies below 3 GHz and voltages below 500 Volts.
Similar connectors using the bayonet connection principle exist, and a threaded connector is also available.
It is an alternative to the RCA connector
when used for composite video
on commercial video devices, although many consumer electronics
devices with RCA jacks can be used with BNC-only commercial video equipment via a simple adapter. BNC connectors were commonly used on 10base2
thin Ethernet
networks, both on cable interconnections and network card
s. The TNC (threaded) connector is used for stable performance at higher frequencies than used with the BNC connector.
BNC connections can also be found in recording studios. Digital recording equipment uses the connection for synchronization of various components via the transmission of word clock
timing signals.
locking mechanism and its inventors, Paul Neill
and Carl Concelman
. Neill worked at Bell Labs
and also invented the N connector
; Concelman worked at Amphenol
and also invented the C connector
.
The basis for the development of the BNC connector was largely the work of Octavio M. Salati, a graduate of the Moore School of Electrical Engineering of the University of Pennsylvania. In 1945, while working at Hazeltine Electronics Corporation, he filed a patent for a connector for coaxial cables that would minimize wave reflection/loss. The patent was granted in 1951.
versions, matched for use with cables of the same characteristic impedance
. The 75 ohm types can sometimes be recognized by the reduced or absent dielectric
in the mating ends. The 50 and 75 ohm connectors are typically specified for use at frequencies up to 4 and 2 GHz respectively.
Video and DS3
Telco central office applications primarily use 75 ohm BNC connectors, where as 50 ohm connectors are used for data and RF. Many VHF receivers used 75 ohm antenna
inputs, so they often used 75 ohm BNC connectors.
and a 75 ohm and a 50 ohm BNC connector which both comply with the 1978 standard, IEC 169-8, will mate non-destructively. At least one manufacturer claims very high reliability for the connectors' compatibility.
At frequencies below 10 MHz the impedance mismatch between a 50 ohm connector or cable and a 75 ohm one has negligible effects. BNC connectors were thus originally made only in 50 ohm versions, for use with any impedance of cable. Above this frequency, however, the mismatch becomes progressively more significant and can lead to signal reflections.
s in broadcast facilities like central apparatus room
s.
They are usually light weight, made with stainless steel
, and have screw driver type plastic
handle grips
for applying rotating torque
. Their shafts are usually double the length of a standard screw driver.
BNC tools help in safely, efficiently and quickly accessing BNC connectors, in jack fields. Using BNC tools also minimizes risk of accidentally disconnecting other connectors close by.
(СР-50 in Cyrillic) and SR-75
(СР-75 in Cyrillic) connectors. As a result of recalculating from imperial to metric measurements their dimensions differ slightly from those of BNC. They are however generally interchangeable with them, sometimes with force applied.
frequencies.
such as RG-108A. They can operate up to 100 MHz and 100 volts. They cannot mate with ordinary BNC connectors.
(also known as triax) connectors are a variant on BNC which carry both a signal and guard as well as ground conductor. These are used in sensitive electronic measurement systems, such as those made by Keithley
. Early ones were designed with just an extra inner conductor, but later triaxial connectors also include a three-lug arrangement to rule out an accidental forced mating with a BNC connector. Adaptors exist to allow some interconnection possibilities between triax and BNC connectors.
and SHV
connectors are typically used. MHV connectors are easily mistaken for BNC type, and can be made to mate with them by brute force. The SHV connector was developed as a safer alternative, and will not mate with ordinary BNC connectors.
00 miniature connectors which allow for higher densities. In video broadcast industry, the DIN 1.0/2.3 and the HD-BNC connector are used for higher density products.
RF connector
A coaxial RF connector is an electrical connector designed to work at radio frequencies in the multi-megahertz range.RF connectors are typically used with coaxial cables and are designed to maintain the shielding that the coaxial design offers. Better models also minimize the change in transmission...
used for coaxial cable
Coaxial cable
Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
. It is used with radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
, television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
, and other radio-frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
electronic
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
equipment, test instruments, video signals, and was once a popular computer network connector. BNC connectors are made to match the characteristic impedance
Characteristic impedance
The characteristic impedance or surge impedance of a uniform transmission line, usually written Z_0, is the ratio of the amplitudes of a single pair of voltage and current waves propagating along the line in the absence of reflections. The SI unit of characteristic impedance is the ohm...
of cable at either 50 ohms or 75 ohms. It is usually applied for frequencies below 3 GHz and voltages below 500 Volts.
Similar connectors using the bayonet connection principle exist, and a threaded connector is also available.
Use
The BNC connector is used for signal connections such as:- analogAnalog videoAnalog video is a video signal transferred by an analog signal. An analog color video signal contains luminance, brightness and chrominance of an analog television image...
and serial digital interfaceSerial Digital InterfaceSerial digital interface is a family of video interfaces standardized by SMPTE. For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video...
video signals - amateur radioAmateur radioAmateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
antennas - aviation electronics (avionicsAvionicsAvionics are electronic systems used on aircraft, artificial satellites and spacecraft.Avionic systems include communications, navigation, the display and management of multiple systems and the hundreds of systems that are fitted to aircraft to meet individual roles...
) - test equipmentElectronic test equipmentElectronic test equipment is used to create signals and capture responses from electronic Devices Under Test . In this way, the proper operation of the DUT can be proven or faults in the device can be traced and repaired...
.
It is an alternative to the RCA connector
RCA connector
An RCA connector, sometimes called a phono connector or cinch connector, is a type of electrical connector commonly used to carry audio and video signals...
when used for composite video
Composite video
Composite video is the format of an analog television signal before it is combined with a sound signal and modulated onto an RF carrier. In contrast to component video it contains all required video information, including colors in a single line-level signal...
on commercial video devices, although many consumer electronics
Consumer electronics
Consumer electronics are electronic equipment intended for everyday use, most often in entertainment, communications and office productivity. Radio broadcasting in the early 20th century brought the first major consumer product, the broadcast receiver...
devices with RCA jacks can be used with BNC-only commercial video equipment via a simple adapter. BNC connectors were commonly used on 10base2
10BASE2
10BASE2 is a variant of Ethernet that uses thin coaxial cable , terminated with BNC connectors...
thin Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
networks, both on cable interconnections and network card
Network card
A network interface controller is a computer hardware component that connects a computer to a computer network....
s. The TNC (threaded) connector is used for stable performance at higher frequencies than used with the BNC connector.
BNC connections can also be found in recording studios. Digital recording equipment uses the connection for synchronization of various components via the transmission of word clock
Word clock
A word clock or wordclock is a clock signal used to synchronise other devices, such as digital audio tape machines and compact disc players, which interconnect via digital audio. S/PDIF, AES/EBU, ADAT, and TDIF are some of the formats that use a word clock...
timing signals.
Origin
The connector was named after its bayonet mountBayonet mount
A bayonet mount or bayonet connector is a fastening mechanism consisting of a male side with one or more pins, and a female receptor with matching L slots and spring to keep the two parts locked together....
locking mechanism and its inventors, Paul Neill
Paul Neill
Paul Neill was an electrical engineer at Bell Labs in the 1940s and 1950s. He is credited with helping to invent the BNC, TNC and Type N connectors used for microwave and RF communications....
and Carl Concelman
Carl Concelman
Carl Concelman was the electrical engineer who, while working for Amphenol, invented the C connector and teamed up with Paul Neill of Bell Labs to invent the BNC connector....
. Neill worked at Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
and also invented the N connector
N connector
The N connector is a threaded RF connector used to join coaxial cables. It was one of the first connectors capable of carrying microwave-frequency signals, and was invented in the 1940s by Paul Neill of Bell Labs, after whom the connector is named.-Design:Originally, the connector was designed to...
; Concelman worked at Amphenol
Amphenol
Amphenol Corporation is a major producer of electronic and fiber optic connectors, cable and interconnect systems such as Coaxial cables. Amphenol is a portmanteau from the corporation's original name, American Phenolic Corp....
and also invented the C connector
C connector
The C connector is a type of RF connector used for terminating coaxial cable. Coupling uses two-stud bayonet-type locks. The C connector was invented by Amphenol engineer Carl Concelman. It is weatherproof without being overly bulky....
.
The basis for the development of the BNC connector was largely the work of Octavio M. Salati, a graduate of the Moore School of Electrical Engineering of the University of Pennsylvania. In 1945, while working at Hazeltine Electronics Corporation, he filed a patent for a connector for coaxial cables that would minimize wave reflection/loss. The patent was granted in 1951.
Types
BNC connectors exist in 50 and 75 ohmOhm
The ohm is the SI unit of electrical resistance, named after German physicist Georg Simon Ohm.- Definition :The ohm is defined as a resistance between two points of a conductor when a constant potential difference of 1 volt, applied to these points, produces in the conductor a current of 1 ampere,...
versions, matched for use with cables of the same characteristic impedance
Characteristic impedance
The characteristic impedance or surge impedance of a uniform transmission line, usually written Z_0, is the ratio of the amplitudes of a single pair of voltage and current waves propagating along the line in the absence of reflections. The SI unit of characteristic impedance is the ohm...
. The 75 ohm types can sometimes be recognized by the reduced or absent dielectric
Dielectric
A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
in the mating ends. The 50 and 75 ohm connectors are typically specified for use at frequencies up to 4 and 2 GHz respectively.
Video and DS3
Digital Signal 3
A Digital Signal 3 is a digital signal level 3 T-carrier. It may also be referred to as a T3 line.*The data rate for this type of signal is 44.736 Mbit/s.*This level of carrier can transport 28 DS1 level signals within its payload....
Telco central office applications primarily use 75 ohm BNC connectors, where as 50 ohm connectors are used for data and RF. Many VHF receivers used 75 ohm antenna
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
inputs, so they often used 75 ohm BNC connectors.
Compatibility
The different versions are designed to mate with each other,and a 75 ohm and a 50 ohm BNC connector which both comply with the 1978 standard, IEC 169-8, will mate non-destructively. At least one manufacturer claims very high reliability for the connectors' compatibility.
At frequencies below 10 MHz the impedance mismatch between a 50 ohm connector or cable and a 75 ohm one has negligible effects. BNC connectors were thus originally made only in 50 ohm versions, for use with any impedance of cable. Above this frequency, however, the mismatch becomes progressively more significant and can lead to signal reflections.
BNC inserter/remover tool
A BNC inserter/remover tool also called a BNC tool, BNC extraction tool or BNC apple corer, is used to insert or remove BNC connectors in high density or hard-to-reach locations, such as densely wired patch panelPatch panel
A patch panel or patch bay is a panel, typically rackmounted, that houses cable connections. One typically shorter patch cable will plug into the front side, whereas the back holds the connection of a much longer and more permanent cable...
s in broadcast facilities like central apparatus room
Central Apparatus Room
In broadcast facilities, a central apparatus room , central machine room, or central equipment room , or central technical area , or rack room is where shared equipment common to all technical areas is located. Some broadcast facilities have several of these rooms...
s.
They are usually light weight, made with stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
, and have screw driver type plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
handle grips
Handle (grip)
A handle is a part of, or attachment to, an object that can be moved or used by hand. The design of each type of handle involves substantial ergonomic issues, even where these are dealt with intuitively or by following tradition...
for applying rotating torque
Torque
Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....
. Their shafts are usually double the length of a standard screw driver.
BNC tools help in safely, efficiently and quickly accessing BNC connectors, in jack fields. Using BNC tools also minimizes risk of accidentally disconnecting other connectors close by.
SR-50 and SR-75
In the USSR, BNC connectors were copied as SR-50SR-50 connector
The SR-50 connectors are Russian-made 50 ohm RF connectors for coaxial cables.Some of the CP-50 connectors are versions of the 50 ohm BNC connector...
(СР-50 in Cyrillic) and SR-75
SR-75 connector
The SR-75 connectors are Russian-made 75 ohm RF connectors for coaxial cables.Some of the CP-75 connectors are versions of the 75 ohm BNC connector...
(СР-75 in Cyrillic) connectors. As a result of recalculating from imperial to metric measurements their dimensions differ slightly from those of BNC. They are however generally interchangeable with them, sometimes with force applied.
TNC (Threaded Neill–Concelman)
A threaded version of the BNC connector, known as the TNC connector (for Threaded Neill-Concelman) is also available. It has superior performance to the BNC connector at microwaveMicrowave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
frequencies.
Twin BNC or twinax
Twin BNC (also known as twinax) connectors use the same bayonet latching shell as an ordinary BNC connector but contain two independent contact points (one male and one female), allowing the connection of a 78 ohm or 95 ohm shielded differential pairDifferential pair
A differential pair is a pair of conductors used for differential signaling. Differential pairs are usually found on a printed circuit board, in cables , and in connectors...
such as RG-108A. They can operate up to 100 MHz and 100 volts. They cannot mate with ordinary BNC connectors.
Triaxial
TriaxialTriaxial cable
Triaxial Cable, often referred to as triax for short, is a type of electrical cable similar to coaxial cable, but with the addition of an extra layer of insulation and a second conducting sheath. It provides greater bandwidth and rejection of interference than coax, but is more expensive...
(also known as triax) connectors are a variant on BNC which carry both a signal and guard as well as ground conductor. These are used in sensitive electronic measurement systems, such as those made by Keithley
Keithley Instruments
Keithley Instruments is a measurement and instrument company headquartered in Solon, Ohio, that develops, manufactures, markets, and sells data acquisition products, as well as complete system solutions for high-volume production and assembly testing...
. Early ones were designed with just an extra inner conductor, but later triaxial connectors also include a three-lug arrangement to rule out an accidental forced mating with a BNC connector. Adaptors exist to allow some interconnection possibilities between triax and BNC connectors.
High voltage connectors
For higher voltages (above 500 V), MHVMHV connector
The MHV connector is a type of RF connector used for terminating coaxial cable.The connector looks almost identical to a typical BNC connector, but is not designed to mate with BNC jacks. MHV connectors can be recognized by the slightly protruding insulation on the male plug and the slightly...
and SHV
SHV connector
The SHV connector is a type of RF connector used for terminating a coaxial cable.The connector uses a bayonet mount similar to those of the BNC and MHV connectors, but is easily distinguished due to its very thick and protruding insulator...
connectors are typically used. MHV connectors are easily mistaken for BNC type, and can be made to mate with them by brute force. The SHV connector was developed as a safer alternative, and will not mate with ordinary BNC connectors.
Miniature connectors
BNC connectors are commonly used in electronics, but they are replaced by LEMOLEMO
LEMO is both the name of an electronic and fibre optic connector manufacturer based in Switzerland, and the name commonly used to refer to push-pull connectors made by that company, which are used in medical, industrial, audio/visual, telecommunications, military, scientific research and...
00 miniature connectors which allow for higher densities. In video broadcast industry, the DIN 1.0/2.3 and the HD-BNC connector are used for higher density products.