The F connector (also F-type connector) is a coaxial RF connector commonly used for "over the air"

terrestrial television Terrestrial television or over-the-air television (OTA) is a type of television broadcasting in which the signal transmission occurs via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an ante ...

cable television Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with bro ...

and universally for

satellite television Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location. The signals are received via an outdoor parabolic antenna com ...

and cable modems, usually with RG-6/U cable or with RG-59/U cable. The F connector was invented by Eric E. Winston in the early 1950s while working for Jerrold Electronics on their development of cable television. In the 1970s, it became commonplace on VHF, and later UHF, television antenna connections in the United States, as coaxial cables replaced

twin-lead Twin-lead cable is a two-conductor flat cable used as a balanced transmission line to carry radio frequency (RF) signals. It is constructed of two stranded or solid copper or copper-clad steel wires, held a precise distance apart by a plastic ( ...

. It is now specified in IEC 61169-24:2019.

Description

The F connector is an inexpensive, gendered, threaded, compression connector for radio frequency signals. It has good 75 Ω impedance match for frequencies well over 1 GHz and has usable bandwidth up to several GHz. Connectors mate using a 3/8-32

UNEF UNEF may refer to: * United Nations Emergency Force, a UN force deployed in the Middle East in 1956 * UNEF, a designation for Extra-Fine thread series of Standard Unified Screw Threads (ANSI B1.1) * Union Nationale des Étudiants de France (Natio ...

thread. The female connector has a socket for the center conductor and external threads. The male connector has a center pin, and a captive nut with internal threads. The design allows for low-cost construction, where cables are terminated almost exclusively with male connectors. The coaxial cable center conductor forms the pin, and cable dielectric extends up to the mating face of the connector. Thus, the male connector consists of only a body, which is generally crimped onto or screwed over the cable shielding braid, and a captive nut, neither of which require tight tolerances. Push-on versions are also available. Female connectors are typically used on bulkheads or as couplers, often being secured with the same threads as for the connectors. They can be manufactured as a single piece, with center sockets and dielectric, entirely at the factory where tolerances can easily be controlled. This design is sensitive to the surface properties of the inner conductor (which must be solid wire, not stranded).

Weatherproofing

The F connector is not weatherproof. Neither the threads nor the joint between male connector body and captive nut provide a water-tight seal. However, male connectors are commonly enhanced with an o-ring (of about 7mm) inside the captive nut. This seals between the mating faces of both connectors, providing some protection for the center conductor. Alternatively, waterproof versions or enclosures are recommended for outside use (for example, on antennas). Corrosion resistance, reliability of connector electrical conduction and water resistance can be improved by coating all bare copper wires and the connectors themselves with

silicone grease Silicone grease, sometimes called dielectric grease, is a waterproof grease made by combining a silicone oil with a thickener. Most commonly, the silicone oil is polydimethylsiloxane (PDMS) and the thickener is amorphous fumed silica. Using this ...

Usage

The cable and satellite television entities (as a near standard practice) use compression fittings with F connectors on customer premises. In Europe, block down-converted satellite signals (950–2150 MHz) from LNBs and DC power and block signalling from satellite receivers are near exclusively passed through F connectors.

Flex F connectors

Push-on (aka Flex) F connectors provide poorer shielding against microwave signals of high

field strength In physics, field strength means the '' magnitude'' of a vector-valued field (e.g., in volts per meter, V/m, for an electric field ''E''). For example, an electromagnetic field results in both electric field strength and magnetic field streng ...

. This leakage problem is more an artifact of bent or partly broken push on connectors, but is mostly not observed with compression connectors. Nearby television, FM radio, mobile & cordless phones, government radiolocation (54–1,002 MHz)Cityfreq United States Scanner Frequencies, Phone Numbers, and IP Addresses.
/ref> transmitters can potentially interfere with a CATV or DTH Satellite reception or operation if the Flex connector is poorly installed. File:Commutateur-diseqc4x1-switch.jpg, F connectors attached to a 4-way DiSEqC switch. File:Flex Coax Connector F Type.jpg, A visual collection of standard and right-angle coaxial F connectors, a commonly used but less documented form of the F connector.

Notes

References

External links

Compression Tool for crimping

Antenna-cables&connectors
{{DEFAULTSORT:F Connector RF connectors Television technology