The F connector is a coaxial RF connector commonly used for “over the air” terrestrial television, cable television and universally for satellite television and cable modems, usually with RG-6/U cable or, in older installations, 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 television antenna connections in the United States, as coaxial cables replaced twin-lead, and later for UHF also.
The F connector is inexpensive, yet has good 75 Ω impedance match for frequencies well over 1 GHz and has usable bandwidth up to several GHz. One reason for its low cost is that it commonly uses the solid conductor (center wire) of the specified types of coaxial cable as the pin of the male connector. Universally, stainless steel is used for all types of F connectors – as opposed to aluminum for Belling-Lee connectors.
This design is subject to the surface properties of the inner conductor (which must be solid wire) and is not corrosion resistant; hence waterproof versions are needed for outside use (for example, on aerials).
Corrosion resistance can be improved by coating all bare copper wires with silicone grease. The male connector body is typically crimped, or sometimes screwed, on to the exposed outer braid. Female F Type connectors have an external 3/8-32 UNEF thread (9.5 mm diameter). Most male connectors have a matching internally threaded connecting ring, though push-on versions are also available.