The TNC connector (initialism of "Threaded Neill–Concelman") is a threaded version of the

BNC connector The BNC connector is a miniature quick-connect/disconnect RF connector, radio-frequency connector for coaxial cable. It was introduced on military radio equipment in the 1940s, and has since become widely used in radio systems and as a common t ...

Description

The interface specifications for the TNC and many other connectors are referenced in MIL-STD-348. The connector has a 50 Ω impedance and operates best in the 0–11

GHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose formal expression in ter ...

frequency spectrum. It has better performance than the BNC connector at

microwave Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300&n ...

frequencies. Invented in the late 1950s and named after Paul Neill of

Bell Labs Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, Murray Hill, New Jersey, the compa ...

and Carl Concelman of

Amphenol Amphenol Corporation is an American 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. History Amph ...

, the TNC connector has been employed in a wide range of radio and wired applications. The TNC connector features a 7/16"-28 thread, not to be confused with a

7/16 DIN connector The 7-16 DIN connector or 7/16 (seven and sixteen millimeter DIN) is a 50 Ω threaded RF connector used to join coaxial cables. It was designed to reduce passive intermodulation from multiple transmitters. It is among the most widely used high pow ...

, which is the diameter of the mating surfaces as specified in millimeters.

Variations

Reverse-polarity TNC

Reverse-polarity TNC (RP-TNC, sometimes RTNC) is a variation of the TNC specification which reverses the polarity of the interface. A reverse polarity connector will have the opposite pin of standard connector. Gender is determined by the threading of the connector. On a male connector, the threading will be on the inside. On a female connector the threading is on the outside. Because they were not readily available, RP-TNC connectors have been widely used by

Wi-Fi Wi-Fi () is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for Wireless LAN, local area networking of devices and Internet access, allowing nearby digital devices to exchange data by ...

equipment manufacturers to comply with specific local regulations, such as those from the

FCC The Federal Communications Commission (FCC) is an independent agency of the United States government that regulates communications by radio, television, wire, internet, wi-fi, satellite, and cable across the United States. The FCC maintains ju ...

, which are designed to prevent consumers from connecting antennas which exhibit gain and therefore breach compliance. The FCC considered that the RP-TNC was acceptable in preventing consumers changing the antenna; but by 2000 it regarded them as readily available, though delaying its ruling indefinitely. As of 2013, leading manufacturers are still using RP-TNC connectors on their Wi-Fi equipment.

TNCA

The TNCA connector is a variant of the TNC connector specified in MIL-STD-348 designed to provide an air gap in the dielectric region between the male and female connectors. The female TNCA connector is nearly identically to the standard TNC female connector, while the male TNCA connector provides the air cavity differentiating it from a standard male TNC connector. As such, TNCA connectors are mechanically compatible with standard TNC connectors.

75 ohm TNC

Most TNC connectors are 50-ohm type even when used with

coaxial cable Coaxial cable, or coax (pronounced ), is a type of electrical cable consisting of an inner Electrical conductor, conductor surrounded by a concentric conducting Electromagnetic shielding, shield, with the two separated by a dielectric (Insulat ...

of other impedances, but a 75-ohm series is also available, providing a good SWR to about 1 GHz. These can be recognized by a reduced amount of

dielectric In electromagnetism, a dielectric (or dielectric medium) is an Insulator (electricity), electrical insulator that can be Polarisability, polarised by an applied electric field. When a dielectric material is placed in an electric field, electric ...

in the mating ends. They are intermatable with standard types.

References