RF (F-type)
RF (F-type) is a 75Ω coaxial RF connector widely used for terrestrial television antennas, cable television, satellite television, and cable modems. It is the most common RF connector found on consumer CRT televisions in North America and has been a standard connection for TV equipment since the 1970s.
History
The F connector was invented by Eric E. Winston in the early 1950s while working for Jerrold Electronics, a company developing equipment for the emerging cable television industry.[1][2] The connector became commonplace on VHF television antenna connections in the United States during the 1970s, and later on UHF connections as well, as 75Ω coaxial cable gradually replaced 300Ω twin-lead ribbon cable for home antenna installations.[3]
The F connector's design prioritized low manufacturing cost and ease of termination. The cable's own solid center conductor serves as the connector's center pin, eliminating the need for a separate contact and keeping the part count minimal.[2] This made it well suited for mass deployment in residential cable TV systems and consumer electronics.
Design
The F connector is a gendered, threaded compression connector. Male connectors are used to terminate cables, while female connectors (also called jacks or ports) are mounted on equipment panels and used as inline couplers. The connectors mate using a 3/8-32 UNEF thread, providing a secure mechanical and electrical connection.[3]
On television rear panels, the F-type jack is typically a panel-mount female connector, often labeled "ANT," "VHF," "VHF/UHF," "CATV," or "75Ω." Push-on (unthreaded) variants also exist but provide inferior shielding compared to threaded versions.[3]
The connector is not inherently weatherproof, though versions with O-ring seals are available for outdoor antenna installations.[3]
Specifications
| Parameter | Value |
|---|---|
| Impedance | 75Ω |
| Usable frequency range | DC to well over 1 GHz |
| Thread | 3/8-32 UNEF |
| Common cable types | RG-6/U, RG-59/U |
| Standard | IEC 61169-24:2019[4] |
Common Uses on CRT Televisions
On CRT sets, the F-type connector serves as the primary antenna/cable input. Common configurations include:
- Single F-type jack (labeled "ANT" or "VHF/UHF") — found on most sets from the mid-1980s onward, where a single 75Ω input feeds an internal splitter for both VHF and UHF bands
- Separate VHF (F-type) and UHF (300Ω twin-lead) — common on earlier sets from the 1970s through early 1990s, where each band has its own dedicated input and connector type
- Dual F-type jacks — less common; separate 75Ω inputs for VHF and UHF
For sets with only twin-lead antenna terminals, a 75Ω-to-300Ω balun adapter allows connection of coaxial cable.
See Also
- RF (300Ω twin-lead) — 300Ω balanced twin-lead screw terminals
- RF (Belling-Lee) — 75Ω push-on RF connector, standard in Europe
- RCA (connector) — Common audio/video connector
References
- ↑ Eric E. Winston, "Electrical Connector", US Patent 3,537,065, filed 1968.
- ↑ 2.0 2.1 "F Type Connector for TV Coax Cables", Electronics Notes.
- ↑ 3.0 3.1 3.2 3.3 "F connector", Wikipedia.
- ↑ "IEC 61169-24:2019: Radio-frequency connectors — Part 24", International Electrotechnical Commission.
