View source for RF (300Ω twin-lead)

'''RF (300Ω twin-lead)''' is a balanced antenna connection using flat twin-lead ribbon cable, terminated at the television via a pair of screw terminals. It was the original standard for connecting VHF and UHF antennas to television receivers in North America and remained common through the 1990s.

== Overview ==

[[File:JVC AV-2556 photo 6.jpg|thumb|300px|Rear panel of a [[JVC AV-2556]] showing 300Ω twin-lead screw terminals (left, labeled "UHF") alongside a 75Ω [[RF (F-type)]] coaxial jack (center, labeled "VHF").]]

Twin-lead is a balanced transmission line consisting of two parallel conductors separated by a flat plastic insulator, with a characteristic impedance of 300Ω. The cable connects to the television through a pair of spade-lug screw terminals on the rear panel, typically labeled with the band (UHF or VHF) and impedance.

On many sets from the 1970s through early 1990s, the UHF input used 300Ω twin-lead terminals while the VHF input used a 75Ω [[RF (F-type)]] coaxial connector. A 75Ω-to-300Ω balun adapter can be used to bridge between the two cable types.

== Characteristics ==

{| class="wikitable"
! Parameter !! Value
|-
| Impedance || 300Ω (balanced)
|-
| Cable type || Flat twin-lead ribbon
|-
| Termination || Spade lugs or bare wire under screw terminals
|}

== See Also ==

* [[RF (F-type)]] — 75Ω coaxial F-type connector
* [[RF (Belling-Lee)]] — 75Ω push-on RF connector common in Europe

[[Category:Connector types]]