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	{{short description\|RF connector for ~~coax~~ cable}}		{{short description\|Radio-frequency connector for coaxial cable}}
	{{Use dmy dates\|date=~~July~~ ~~2013~~}}		{{Use dmy dates\|date=January 2024}}
	{{Infobox connector		{{Infobox connector
	\|name = BNC connector		\|name = BNC connector
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	\|logo =		\|logo =
	\|caption = Male 50 ohm BNC connector		\|caption = Male 50 ohm BNC connector
	\|designer = ], ]		\|designer = ]
	\|design_date = ~~1940s~~		\|design_date = 1944
	\|manufacturer = Various		\|manufacturer = Various
	\|diameter = Outer, typical: <br />		\|diameter = Outer, typical: <br />
	{{plainlist\|		{{plainlist\|
	*{{convert\|0.570\|in\|mm\|abbr=on}}, male		* {{convert\|0.570\|in\|mm\|abbr=on}}, male
	*{{convert\|0.436\|in\|mm\|abbr=on}}, female		* {{convert\|0.436\|in\|mm\|abbr=on}}, female
	}}		}}
	\|width =		\|width =
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	\|maximum_voltage =		\|maximum_voltage =
	\|maximum_current =		\|maximum_current =
	\|cable = ]		\|cable = ]
	\|passband = Typically 0–4 GHz		\|passband = Typically 0–4 GHz
	\|physical_connector =		\|physical_connector =
	}}		}}

	The '''BNC connector''' ~~(initialism of "Bayonet Neill–Concelman")~~ is a miniature quick connect/disconnect ] used for ]. It is designed to maintain the same ] of the cable, with 50 ohm and 75 ohm types being made. It is usually applied for video and radio frequency connections up to about 2 GHz and up to 500 volts. The connector has a twist to lock design with two lugs in the female portion of the connector engaging a slot in the shell of the male portion. The type was introduced on military radio equipment in the 1940s and has since become widely applied in radio systems, and is a common type of video connector. Similar radio-frequency connectors differ in dimensions and attachment features, and may allow for higher voltages, higher frequencies, or three-wire connections.		The '''BNC connector''' is a miniature quick connect/disconnect ] used for ]. It is designed to maintain the same ] of the cable, with 50 ohm and 75 ohm types being made. It is usually applied for video and radio frequency connections up to about 2 GHz and up to 500 volts. The connector has a twist to lock design with two lugs in the female portion of the connector engaging a slot in the shell of the male portion. The type was introduced on military radio equipment in the 1940s and has since become widely applied in radio systems, and is a common type of video connector. Similar radio-frequency connectors differ in dimensions and attachment features, and may allow for higher voltages, higher frequencies, or three-wire connections.

			== History ==

			In 1941, the US Navy used a smaller version of the threaded ], the Type BN (Baby N), as the UG-85/U, UG-86/U, UG-114/U and UG-115/U.

			In 1943, the British introduced a ¼ inch 50 ohm coaxial cable, and companies immediately developed many connectors for it. In 1944, the US Navy called the designers together to find a single, standard design acceptable to all. ], the inventor of the original N connector, developed a prototype connector which had a constant 50 ohm impedance at frequencies beyond 1 GHz, used a bayonet fastening (faster to use than a threaded one), and was easier to manufacture and assemble. It was specified by the ] drawing ESL 662916, dated March 2, 1944.

			In April 1944, the Navy took Neill’s design, added a ''C'' (for ''constant impedance)'' to ''BN'' to get ''Type BNC'' (''Baby Neill Constant''), and assigned part numbers UG 88/U to the male and UG 89/U to the female (Amphenol still makes them). The Navy issued a final drawing RE 49F 246, dated December 2, 1944. <ref>{{cite web \|title=Hazeltine Research, Inc. v. Dage Elec. Co. \|url=https://casetext.com/case/hazeltine-research-inc-v-dage-elec-co \|website=Casetext \|access-date=7 January 2025 \|at=Section 13 and ''Prior knowledge'' section}}</ref>

			In May 1945, ] of ] applied for a patent for the BNC, which was granted in January 1951.<ref> {{cite patent \|country=USA \|number= US2540012A\|inventor= \|invent1= Octavio M. Salati \|title= Electrical connector \|pubdate= 1945-05-19 \|gdate= 1951-01-30\|url=https://patents.google.com/patent/US2540012A/en}}</ref> In 1958, Hazeltine sued Dage Electric Company, a maker of BNC connectors, for infringement on this patent. The court found that Salati’s patent was invalid because he knew of the Navy’s BNC before his application date <ref>{{cite web \|title=Hazeltine Research, Inc. v. Dage Elecric Co. 165 F.Supp. 226 (S.D.Ind. 1958) 118 U.S.P.Q. 397 No. IP 56-C-15. United States District Court, S.D. Indiana, Indianapolis Division. July 31, 1958. \|url=https://casetext.com/case/hazeltine-research-inc-v-dage-elec-co \|website=Casetext \|access-date=7 January 2025}}</ref>.

			==Name==

			The US Navy used the term ''BNC'' to mean "Baby Neill Constant".
			The term ''BNC'' appeared in 1948 in ads for ] connectors<ref name="RadiosMaster">{{cite web \|title=Radio's Master catalog 13th edition \|url=https://www.worldradiohistory.com/Archive-Catalogs/Radios-Master/Radio's-Master-13th-1948.pdf \|website=Word Radio History \|publisher=U.C.P. Inc. \|access-date=5 January 2025 \|pages=T-14 \|format=pdf}}</ref> together with the MIL-spec name ''UG-88/U''.

			While Paul Neill and ] did not invent the BNC, it is often suggested that BNC means ''Bayonet Neill–Concelman''.<ref name=Lee04>Thomas H. Lee, ''Planar microwave engineering: a practical guide to theory, measurement, and circuits, Volume 1'' Cambridge University Press, p. 111 (2004). {{ISBN\|0-521-83526-7}}.</ref> At the time of the BNC development, Concelman worked at ] and invented the ] as an improvement to the BNC. In the late 1950s, at Amphenol, Neill and Concelman invented the ], which could mean ''Threaded BNC'' or ''Threaded Neill–Concelman''. This may have led some to incorrectly assume that they must also have developed the BNC and created ''Bayonet Neill–Concelman'' as a ].

			Other suggestions include ''Bayonet Navy Connector'':<ref>{{cite book \|title=1979-80 Coaxial & Waveguide Catalog and Microwave Measurement Handbook \|publisher=Hewlett-Packard}}</ref> ''Bayonet N Connector'', ''Bayonet Nut Coupling'', ''Barrel Nut Connector'', ''Bayonet Nipple Connector'', ''Baby N Connector'', ''British Naval/National Connector'', and ''Berkeley Nucleonics Corporation''.

	==Description ==		==Description ==

	The BNC connector features two bayonet lugs on the female connector; mating is fully achieved with a quarter turn of the coupling nut. It uses an outer conductor with slots and some plastic dielectric on each gender connector. This dielectric causes increasing losses at higher frequencies. Above 4 GHz, the slots may radiate signals, so the connector is usable, but not necessarily stable, up to about 11 GHz. BNC connectors are made to match the ] of cable at either 50 ohms or 75 ohms (with other impedances such as 93 ohms for ] available though less common). They are usually applied for voltages below 500 volts.<ref name="amphenol">, Amphenol Connex</ref> The interface specifications for the BNC and many other connectors are referenced in MIL-STD-348.<ref name="MIL-STD-348">{{cite book \|title=RADIO FREQUENCY CONNECTOR INTERFACES FOR MIL-DTL-3643, MIL-DTL-3650, MIL-DTL-3655, MIL-DTL-25516, MIL-PRF-31031, MIL-PRF-39012, MIL-PRF-49142, MIL-PRF-55339, MIL-DTL-83517 \|date=2017-01-22 \|publisher=US DOD \|edition=B with change 3 \|url=http://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=35726}}</ref>		The BNC connector features two bayonet lugs on the female connector; mating is fully achieved with a quarter turn of the coupling nut. It uses an outer conductor with slots and some plastic dielectric on each gender connector. This dielectric causes increasing losses at higher frequencies. Above 4 GHz, the slots may radiate signals, so the connector is usable, but not necessarily stable, up to about 11 GHz. BNC connectors are made to match the ] of cable at either 50 ohms or 75 ohms (with other impedances such as 93 ohms for ] available though less common). They are usually applied for frequencies below 4 GHz<ref name=Lee04/> and voltages below 500 volts.<ref name="amphenol">, Amphenol Connex</ref> The interface specifications for the BNC and many other connectors are referenced in MIL-STD-348.<ref name="MIL-STD-348">{{cite book \|title=RADIO FREQUENCY CONNECTOR INTERFACES FOR MIL-DTL-3643, MIL-DTL-3650, MIL-DTL-3655, MIL-DTL-25516, MIL-PRF-31031, MIL-PRF-39012, MIL-PRF-49142, MIL-PRF-55339, MIL-DTL-83517 \|date=2017-01-22 \|publisher=US DOD \|edition=B with change 3 \|url=http://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=35726}}</ref>

	==~~Use~~==		==Usage==
	]		]

	The BNC was originally designed for military use and has gained wide acceptance in video and RF applications to 2 GHz. BNC connectors are used with miniature-to-subminiature coaxial cable in radio, television, and other ] ] equipment. They were commonly used for early computer networks, including ], the ], and the ] variant of ].		The BNC was originally designed for military use and has gained wide acceptance in video and RF applications up to 2 GHz. BNC connectors are used with miniature-to-subminiature coaxial cable in radio, television, and other ] ] equipment. They were commonly used for early computer networks, including ], the ], and the ] variant of ].

	The BNC connector is used for signal connections such as:		The BNC connector is used for signal connections such as:
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	*].		*].

	]]]		]]]

	The BNC connector is used for analog ] and ] interconnects on commercial video devices. ] devices with ] jacks can be used with BNC-only commercial video equipment by inserting an adapter. BNC connectors were commonly used on ] thin ] network cables and ]s. BNC connections can also be found in recording studios. Digital recording equipment uses the connection for synchronization of various components via the transmission of ] timing signals.		The BNC connector is used for analog ] and ] interconnects on commercial video devices. ] devices with ] jacks can be used with BNC-only commercial video equipment by inserting an adapter. BNC connectors were commonly used on ] thin ] network cables and ]s. BNC connections can also be found in recording studios. Digital recording equipment uses the connection for synchronization of various components via the transmission of ] timing signals.

	Typically the male connector is fitted to a cable, and the female to a panel on equipment. Cable connectors are often designed to be fitted by ]<ref> {{Dead link\|date=December 2020}}</ref> using a special power or manual tool.<ref></ref>{{failed verification\|date=December 2020}} ]s which strip outer jacket, shield braid, and inner dielectric to the correct lengths in one operation are used.<ref></ref>		Typically the male connector is fitted to a cable, and the female to a panel on equipment. Cable connectors are often designed to be fitted by ]<ref> {{Dead link\|date=December 2020}}</ref> using a special power or manual tool.<ref></ref>{{failed verification\|date=December 2020}} ]s which strip outer jacket, shield braid, and inner dielectric to the correct lengths in one operation are used.<ref></ref>

	==Origin==
	The connector was named the ''BNC'' (for Bayonet Neill–Concelman) after its ] locking mechanism and its inventors, ] and ].<ref name=Lee04>Thomas H. Lee, ''Planar microwave engineering: a practical guide to theory, measurement, and circuits, Volume 1'' Cambridge University Press, p. 111 (2004). {{ISBN\|0-521-83526-7}}.</ref> Neill worked at ] and also invented the ]; Concelman worked at ] and also invented the ].

	==Types and compatibility==		==Types and compatibility==
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	===Types===		===Types===
	BNC connectors are most commonly made in 50 and 75 ] versions, matched for use with cables of the same ]. The 75 ohm types can sometimes be recognized by the reduced or absent ] in the mating ends but this is by no means reliable. There was a proposal in the early 1970s for the dielectric material to be coloured red in 75 ohm connectors, and while this is occasionally implemented, it did not become standard. The 75 ohm connector is dimensionally slightly different from the 50 ohm variant, but the two nevertheless can be made to mate. The 50 ohm connectors are typically specified for use at frequencies up to 4 GHz and the 75 ohm version up to 2 GHz.		BNC connectors are most commonly made in 50 and 75 ] versions, matched for use with cables of the same ]. The 75 ohm types can sometimes be recognized by the reduced or absent ] in the mating ends but this is by no means reliable. There was a proposal in the early 1970s for the dielectric material to be coloured red in 75 ohm connectors, and while this is occasionally implemented, it did not become standard. The 75 ohm connector is dimensionally slightly different from the 50 ohm variant, but the two nevertheless can be made to mate. Note that a male 50 ohm BNC has the pin larger than the one of a 75 ohm male, then it can widen the female, causing a fault connection when inserted later a 75 ohm male connector. The 50 ohm connectors are typically specified for use at frequencies up to 4 GHz and the 75 ohm version up to 2 GHz.

	Video (particularly HD video signals) and ] Telco central office applications primarily use 75 ohm BNC connectors, whereas 50 ohm connectors are used for data and RF. Many VHF receivers used 75 ohm ] inputs, so they often used 75 ohm BNC connectors.		Video (particularly HD video signals) and ] Telco central office applications primarily use 75 ohm BNC connectors, whereas 50 ohm connectors are used for data and RF. Many VHF receivers used 75 ohm ] inputs, so they often used 75 ohm BNC connectors.
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	===Compatibility===		===Compatibility===
	The different versions are designed to mate with each other,<ref name="amphenol"/>{{failed verification\|date=December 2020}}		The different versions are designed to mate with each other,<ref name="amphenol"/>{{failed verification\|date=December 2020}}
	and a 75 ohm and a 50 ohm BNC ~~connector which~~ ~~both~~ comply with the 2007 IEC standard, IEC ~~60169~~-8,<ref name="IEC ~~60169~~-8"> Radio-frequency connectors - Part 8: Sectional specification - RF coaxial connectors with inner diameter of outer conductor 6,5 mm (0,256 in) with bayonet lock - Characteristic impedance 50 Ω (type BNC)</ref> will mate non-destructively. At least one manufacturer<ref name="canford-2">. "In over 15 years and many million BNC connectors we have no first hand experience of incompatibility between 50 ohm and 75 ohm types, other than extremely rare (and very obvious) manufacturing faults."</ref> claims very high reliability for the connectors' compatibility. {{Synthesis inline\|date=December 2020}}		and 75 ohm and 50 ohm BNC connectors that comply with the 2007 IEC standard, IEC 61169-8,<ref name="IEC 61169-8"> Radio-frequency connectors – Part 8: Sectional specification – RF coaxial connectors with inner diameter of outer conductor 6,5 mm (0,256 in) with bayonet lock – Characteristic impedance 50 Ω (type BNC)</ref> will mate non-destructively. At least one manufacturer<ref name="canford-2">. "In over 15 years and many million BNC connectors we have no first hand experience of incompatibility between 50 ohm and 75 ohm types, other than extremely rare (and very obvious) manufacturing faults."</ref> claims very high reliability for the connectors' compatibility. {{Synthesis inline\|date=December 2020}}

	At frequencies below 10 MHz the impedance mismatch between a 50 ohm connector or cable and a 75 ohm one has negligible effects.<ref name="canford-1">, The Canford Group</ref> 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.		At frequencies below 10 MHz the impedance mismatch between a 50 ohm connector or cable and a 75 ohm one has negligible effects.<ref name="canford-1">, The Canford Group</ref> 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.
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	==BNC inserter/remover tool==		==BNC inserter/remover tool==
	]		]
	A '''BNC inserter/remover tool''' also called a '''BNC tool''', '''BNC extraction tool''', '''BNC wrench''', or '''BNC apple corer''', is used to insert or remove BNC connectors in high density or hard-to-reach locations, such as densely wired ]s in broadcast facilities like ]s.		A '''BNC inserter/remover tool''', also called a '''BNC tool''', '''BNC extraction tool''', '''BNC wrench''', or '''BNC apple corer''', is a tool used to insert or remove BNC connectors in high density or hard-to-reach locations, such as densely wired ]s in broadcast facilities like ]s.

	BNC tools are usually light weight, made of ], and have ] type plastic ] for applying ]. Their shafts are usually double the length of a standard connector.		BNC tools are usually light weight, made of ], and have ] type plastic ] for applying ]. Their shafts are usually double the length of a standard connector.
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	{{Main\|TNC connector}}		{{Main\|TNC connector}}
	A threaded version of the BNC connector, known as the ] (for '''Threaded Neill-Concelman''') is also available. It has superior performance to the BNC connector at ] frequencies.		A threaded version of the BNC connector, known as the ] (for '''Threaded Neill-Concelman''') is also available. It has superior performance to the BNC connector at ] frequencies.
⚫	]

	===Twin BNC or twinax===		===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 ] such as RG-108A.<ref>{{cite web \|author=E-Base Interactive \|url=http://www.amphenolrf.com/products/twinbnc.asp \|title=Twin BNC connector series \|publisher=Amphenol RF \|access-date=26 November 2011 \|archive-date=23 July 2008 \|archive-url=https://web.archive.org/web/20080723220858/http://www.amphenolrf.com/products/twinbnc.asp \|url-status=dead }}</ref> They can operate up to 100 MHz and 100 volts. They cannot mate with ordinary BNC connectors. An abbreviation for twinax connectors has been BNO (~~Sühner~~).		'''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 ] such as RG-108A.<ref>{{cite web \|author=E-Base Interactive \|url=http://www.amphenolrf.com/products/twinbnc.asp \|title=Twin BNC connector series \|publisher=Amphenol RF \|access-date=26 November 2011 \|archive-date=23 July 2008 \|archive-url=https://web.archive.org/web/20080723220858/http://www.amphenolrf.com/products/twinbnc.asp \|url-status=dead }}</ref> They can operate up to 100 MHz and 100 volts. They cannot mate with ordinary BNC connectors. An abbreviation for twinax connectors has been BNO ({{interlanguage link\|Huber+Suhner\|de}}).

	===Triaxial===		===Triaxial===
	]] (also known as '''triax''') connectors are a variant on BNC that carry a signal and guard as well as ground conductor. These are used in sensitive electronic measurement systems. Early triaxial connectors 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 triaxial and BNC connectors. The triaxial may also be known as a Trompeter connection.		] ] (also known as '''triax''') connectors are a variant on BNC that carry a signal and guard as well as ground conductor. These are used in sensitive electronic measurement systems. Early triaxial connectors 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 triaxial and BNC connectors. The triaxial may also be known as a Trompeter connection.

	===High-voltage connectors===		===High-voltage connectors===
	{{Main\|MHV connector}}		{{Main\|MHV connector\|SHV connector}}
		⚫	For higher voltages (above 500 V), ] and ] 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: it will not mate with ordinary BNC connectors, and the inner conductor is much harder to accidentally contact.
	{{Main\|SHV connector}}
⚫	For higher voltages (above 500 V), ] and ] 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, it will not mate with ordinary BNC connectors and the inner conductor is much harder to accidentally contact.

	===Miniature connectors===		===Miniature connectors===

Latest revision as of 23:56, 13 January 2025

Radio-frequency connector for coaxial cable

BNC connector
Production history
Male 50 ohm BNC connector
Type	RF coaxial connector
Designer	Paul Neill
Designed	1944
Manufacturer	Various
General specifications
Diameter	Outer, typical: 0.570 in (14.5 mm), male 0.436 in (11.1 mm), female
Cable	Coaxial
Passband	Typically 0–4 GHz

The BNC connector is a miniature quick connect/disconnect radio frequency connector used for coaxial cable. It is designed to maintain the same characteristic impedance of the cable, with 50 ohm and 75 ohm types being made. It is usually applied for video and radio frequency connections up to about 2 GHz and up to 500 volts. The connector has a twist to lock design with two lugs in the female portion of the connector engaging a slot in the shell of the male portion. The type was introduced on military radio equipment in the 1940s and has since become widely applied in radio systems, and is a common type of video connector. Similar radio-frequency connectors differ in dimensions and attachment features, and may allow for higher voltages, higher frequencies, or three-wire connections.

History

In 1941, the US Navy used a smaller version of the threaded N connector, the Type BN (Baby N), as the UG-85/U, UG-86/U, UG-114/U and UG-115/U.

In 1943, the British introduced a ¼ inch 50 ohm coaxial cable, and companies immediately developed many connectors for it. In 1944, the US Navy called the designers together to find a single, standard design acceptable to all. Paul Neill, the inventor of the original N connector, developed a prototype connector which had a constant 50 ohm impedance at frequencies beyond 1 GHz, used a bayonet fastening (faster to use than a threaded one), and was easier to manufacture and assemble. It was specified by the Bell Laboratory drawing ESL 662916, dated March 2, 1944.

In April 1944, the Navy took Neill’s design, added a C (for constant impedance) to BN to get Type BNC (Baby Neill Constant), and assigned part numbers UG 88/U to the male and UG 89/U to the female (Amphenol still makes them). The Navy issued a final drawing RE 49F 246, dated December 2, 1944.

In May 1945, Octavio M. Salati of Hazeltine Corporation applied for a patent for the BNC, which was granted in January 1951. In 1958, Hazeltine sued Dage Electric Company, a maker of BNC connectors, for infringement on this patent. The court found that Salati’s patent was invalid because he knew of the Navy’s BNC before his application date .

Name

The US Navy used the term BNC to mean "Baby Neill Constant". The term BNC appeared in 1948 in ads for Amphenol connectors together with the MIL-spec name UG-88/U.

While Paul Neill and Carl Concelman did not invent the BNC, it is often suggested that BNC means Bayonet Neill–Concelman. At the time of the BNC development, Concelman worked at Danbury Knudsen and invented the C connector as an improvement to the BNC. In the late 1950s, at Amphenol, Neill and Concelman invented the TNC connector, which could mean Threaded BNC or Threaded Neill–Concelman. This may have led some to incorrectly assume that they must also have developed the BNC and created Bayonet Neill–Concelman as a backronym.

Other suggestions include Bayonet Navy Connector: Bayonet N Connector, Bayonet Nut Coupling, Barrel Nut Connector, Bayonet Nipple Connector, Baby N Connector, British Naval/National Connector, and Berkeley Nucleonics Corporation.

Description

The BNC connector features two bayonet lugs on the female connector; mating is fully achieved with a quarter turn of the coupling nut. It uses an outer conductor with slots and some plastic dielectric on each gender connector. This dielectric causes increasing losses at higher frequencies. Above 4 GHz, the slots may radiate signals, so the connector is usable, but not necessarily stable, up to about 11 GHz. BNC connectors are made to match the characteristic impedance of cable at either 50 ohms or 75 ohms (with other impedances such as 93 ohms for ARCNET available though less common). They are usually applied for frequencies below 4 GHz and voltages below 500 volts. The interface specifications for the BNC and many other connectors are referenced in MIL-STD-348.

Usage

The BNC was originally designed for military use and has gained wide acceptance in video and RF applications up to 2 GHz. BNC connectors are used with miniature-to-subminiature coaxial cable in radio, television, and other radio-frequency electronic equipment. They were commonly used for early computer networks, including ARCnet, the IBM PC Network, and the 10BASE2 variant of Ethernet.

The BNC connector is used for signal connections such as:

analog and serial digital interface video signals
radio antennas
aerospace electronics (avionics)
nuclear instrumentation
test equipment.

BNC tee connectors with resistive load terminators

The BNC connector is used for analog composite video and digital video interconnects on commercial video devices. Consumer electronics devices with RCA connector jacks can be used with BNC-only commercial video equipment by inserting an adapter. BNC connectors were commonly used on 10base2 thin Ethernet network cables and network cards. 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.

Typically the male connector is fitted to a cable, and the female to a panel on equipment. Cable connectors are often designed to be fitted by crimping using a special power or manual tool. Wire strippers which strip outer jacket, shield braid, and inner dielectric to the correct lengths in one operation are used.

Types and compatibility

Types

BNC connectors are most commonly made in 50 and 75 ohm 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 but this is by no means reliable. There was a proposal in the early 1970s for the dielectric material to be coloured red in 75 ohm connectors, and while this is occasionally implemented, it did not become standard. The 75 ohm connector is dimensionally slightly different from the 50 ohm variant, but the two nevertheless can be made to mate. Note that a male 50 ohm BNC has the pin larger than the one of a 75 ohm male, then it can widen the female, causing a fault connection when inserted later a 75 ohm male connector. The 50 ohm connectors are typically specified for use at frequencies up to 4 GHz and the 75 ohm version up to 2 GHz.

Video (particularly HD video signals) and DS3 Telco central office applications primarily use 75 ohm BNC connectors, whereas 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.

Reverse-polarity BNC (RP-BNC) is a variation of the BNC specification which reverses the polarity of the interface. In a connector of this type, the female contact normally found in a jack is usually in the plug, while the male contact normally found in a plug is in the jack. This ensures that reverse polarity interface connectors do not mate with standard interface connectors. The SHV connector is a high-voltage BNC variant that uses this reverse polarity configuration.

Smaller versions of the BNC connector, called Mini BNC and High Density BNC (HD BNC), are manufactured by Amphenol. While retaining the electrical characteristics of the original specification, they have smaller footprints giving a higher packing density on circuit boards and equipment backplanes. These connectors have true 75 ohm impedance making them suitable for HD video applications.

Compatibility

The different versions are designed to mate with each other, and 75 ohm and 50 ohm BNC connectors that comply with the 2007 IEC standard, IEC 61169-8, 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, BNC wrench, or BNC apple corer, is a tool used to insert or remove BNC connectors in high density or hard-to-reach locations, such as densely wired patch panels in broadcast facilities like central apparatus rooms.

BNC tools are usually light weight, made of stainless steel, and have screw driver type plastic handle grips for applying torque. Their shafts are usually double the length of a standard connector.

They help to safely, efficiently and quickly connect and disconnect BNC connectors in jack fields. BNC tools facilitate access and minimize the risk of accidentally disconnecting nearby connectors.

Similar connectors

Main article: RF connector

Similar connectors using the bayonet connection principle exist, and a threaded connector is also available. United States military standard MIL-PRF-39012 entitled Connectors, Coaxial, Radio Frequency, General Specification for (formerly MIL-C-39012) covers the general requirements and tests for radio frequency connectors used with flexible cables and certain other types of coaxial transmission lines in military, aerospace, and spaceflight applications.

SR connectors

Main article: SR connector

In the USSR, BNC connectors were copied as SR 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)

Main article: TNC connector

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 microwave 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 pair such as RG-108A. They can operate up to 100 MHz and 100 volts. They cannot mate with ordinary BNC connectors. An abbreviation for twinax connectors has been BNO (Huber+Suhner [de]).

Triaxial

Triaxial (also known as triax) connectors are a variant on BNC that carry a signal and guard as well as ground conductor. These are used in sensitive electronic measurement systems. Early triaxial connectors 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 triaxial and BNC connectors. The triaxial may also be known as a Trompeter connection.

High-voltage connectors

Main articles: MHV connector and SHV connector

For higher voltages (above 500 V), MHV 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: it will not mate with ordinary BNC connectors, and the inner conductor is much harder to accidentally contact.

Miniature connectors

BNC connectors are commonly used in electronics, but in some applications they are being replaced by LEMO 00 miniature connectors which allow for significantly higher densities. In video broadcast industry, the DIN 1.0/2.3 and the HD-BNC connector are used for higher density products

References

"Hazeltine Research, Inc. v. Dage Elec. Co". Casetext. Section 13 and Prior knowledge section. Retrieved 7 January 2025.
USA US2540012A, Octavio M. Salati, "Electrical connector", published 1945-05-19, issued 1951-01-30
"Hazeltine Research, Inc. v. Dage Elecric Co. 165 F.Supp. 226 (S.D.Ind. 1958) 118 U.S.P.Q. 397 No. IP 56-C-15. United States District Court, S.D. Indiana, Indianapolis Division. July 31, 1958". Casetext. Retrieved 7 January 2025.
"Radio's Master catalog 13th edition" (pdf). Word Radio History. U.C.P. Inc. pp. T-14. Retrieved 5 January 2025.
^ Thomas H. Lee, Planar microwave engineering: a practical guide to theory, measurement, and circuits, Volume 1 Cambridge University Press, p. 111 (2004). ISBN 0-521-83526-7.
1979-80 Coaxial & Waveguide Catalog and Microwave Measurement Handbook. Hewlett-Packard.
^ BNC Connector specifications, Amphenol Connex
RADIO FREQUENCY CONNECTOR INTERFACES FOR MIL-DTL-3643, MIL-DTL-3650, MIL-DTL-3655, MIL-DTL-25516, MIL-PRF-31031, MIL-PRF-39012, MIL-PRF-49142, MIL-PRF-55339, MIL-DTL-83517 (B with change 3 ed.). US DOD. 22 January 2017.
Typical crimp BNC connector
Typical manual crimp tool for fitting BNC and other coaxial connectors to cables
Typical coax one-operation stripper
Radio-frequency connectors – Part 8: Sectional specification – RF coaxial connectors with inner diameter of outer conductor 6,5 mm (0,256 in) with bayonet lock – Characteristic impedance 50 Ω (type BNC)
Canford. "In over 15 years and many million BNC connectors we have no first hand experience of incompatibility between 50 ohm and 75 ohm types, other than extremely rare (and very obvious) manufacturing faults."
BNC Connectors, The Canford Group
Trompeter Product Catelog (PDF). Trompeter. p. 51. Archived from the original (PDF) on 25 March 2014. Retrieved 24 January 2015.
MIL-PRF-39012
E-Base Interactive. "Twin BNC connector series". Amphenol RF. Archived from the original on 23 July 2008. Retrieved 26 November 2011.

External links

Media related to BNC connectors at Wikimedia Commons

v t e RF connectors (coaxial)
7/16 DIN APC-7 BNC Belling-Lee connector C F-type FME Hirose U.FL Hirose W.FL IPX Motorola MCX Microdot MMCX N QLS QMA/QN RCA MHV SHV SMA SMB SMC TNC TV aerial plug UHF / Mini-UHF
Variations and alternate names 10-32 2.9 mm (SMA) 7 mm AMC (UFL) IPEX MHF RP-SMA RP-TNC SnapN Triax / Triaxial Twin BNC / Twinax (BNC)
Old or seldom used EIA GR LEMO 00 Musa
See also Audio and video interfaces and connectors Radio frequency Radio spectrum

v t e Audio and video connectors
Analog audio	Banana plug Binding post D-subminiature Euroblock DIN Mini-DIN Audio jack RCA Speaker spring terminal Speakon XLR
Digital audio	BNC D-sub S/PDIF TOSLINK XLR
Video	BNC Component RGB Component YPbPr Composite video D-Terminal DB13W3 DFP DIN Mini-DIN DMS-59 LFH DVI Mini-DVI Micro-DVI RCA S-Video UDI VGA Mini-VGA
Audio and video	ADC Belling-Lee CCJ/EIAJ EVC Type F HDBaseT HDMI DisplayPort mDP MHL (superMHL) Minijack P&D PDMI SCART
Visual charts	List of video connectors
General-purpose	Thunderbolt USB

Audio and video interfaces and connectors

Audio only

Analog	PC System Design Guide connectors: TRS 3.5 mm Balanced audio connectors: TRS 6.35 mm XLR
Digital	S/PDIF connectors: RCA jack, coaxial TOSLINK, optical BNC AES3, AES/EBU connectors: RCA jack XLR TOSLINK, optical BNC

Video only

Analog	VGA connectors: DB-15 DVI-A Composite connectors: RCA jack yellow S-Video connectors: Mini-DIN 4 pin Component connectors: RCA jacks × 3 Composite S-Video, and Component connectors: VIVO using Mini-DIN 9 pin
Digital and analog	DVI connectors: DVI-I/DVI-D

Video and audio

Digital	HDMI connectors: HDMI connector DisplayPort connectors: DisplayPort connector HDBaseT connectors: 8P8C connector

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