RF adapter

An RF adapter with a manual switch and multiple outputs.

An RF adapter, short for radio frequency adapter, also known as a RF modulator, is a device which converts a baseband signal into a radio frequency that can be understood by the target device, usually a television or radio. They were commonly used by 8 and 16-bit home video game console and computers.

In order for a video game console to display on a television, it must produce a signal that the television understands. Prior to the creation of standardized direct input systems like composite, component, and S-video, the only way to send a signal to a television was through its antenna. So, video games had to simulate a radio signal in the same format as a television broadcast. This is what the RF adapter does. The signal is sent from the video game console, converted to radio frequencies by the device, and then connected to the antenna input of the television where the video and audio is interpreted as a television channel.

Hooking up the RF adapter would prevent a television from also being able to accept signal from its antenna, so, to prevent a user from having to disconnect their video game and reconnect their antenna (or vice versa) each time they wanted to switch from video game to television, video game manufacturers added a switch into the RF adapter, and selling it as a "switch box." A user connects both their video game and antenna to the switch box, and the switch box to the television. Switching between the video game and television means flipping the switch to the desire input. The original switch box models required the user to manually switch, but later models included automatic switches which would use the signal from the television antenna by default, but, when the video game console was turned on, would switch to the video game signal.

When televisions began including dedicated composite input plugs, video game manufacturers began incorporating the newer technology into their design. First and second generation consoles exclusively used RF adapters. Third generation consoles primarily used RF adapters, but some incorporated composite connectors as well. Fourth generation consoles had composite output, but still bundled RF adapters with the console. Fifth generation consoles used composite as their default, and didn't bundle RF adapters with the consoles, however OEM adapters could still be purchased separately. Only a couple later generation consoles saw RF adapters made by the original manufacturer, most were 3rd party adapters. Because every console for the first four generations of video games use RF adapters, there were many third party manufacturers, but these also decreased as consoles stopped using them.

Personal

My first video game console was an Atari 2600, which used an RF adapter with a manual switch box. My next console was a Nintendo Entertainment System which used an RF adapter with an automatic switch. My Super Nintendo Entertainment System used the same RF adapter, although, later on I hooked it up using composite plugs. That was the last home console I bought when it was still popular, all the later platforms I own connect through various other forms. Although I own several old consoles which require RF adapters, I never use them, and prefer playing games through emulation.

Platforms

Released	Platform	Adapter	Switch	Game to Adapter	Antenna to Adapter	Adapter to TV	Alternate Output
1972-08-??	Odyssey	Included?	Manual	Proprietary	Coaxial or 300Ω and 70Ω clips	Clips	None.
1976-11-??	Channel F	Included?	?	?	?	?
1977-09-??	Atari 2600	Included	Manual	RCA	Clips	Clips	None.
1977-??-??	Odyssey 2000	Included	Manual	Proprietary	Clips	Clips	None.
1978-??-??	Astrocade	Included?	Manual	RCA	Clips	Clips	None.
1978-12-??	Odyssey 2	Included?	?	?	?	?	None.
1980-??-??	Intellivision	Included?	?	?	?	?	None.
1982-05-??	Arcadia 2001	Included	Manual	Proprietary	Coaxial or 300Ω and 70Ω clips	Clips	None.
1982-08-??	ColecoVision	Included	Manual	RCA	Clips	Clips	None.
1982-11-??	Atari 5200	Included	Manual	RCA	Coaxial, alternate model also has 300Ω clips	Coaxial
1983-07-15	Sega SG-1000	Included?	?	?	?	?	None.
1983-07-15	Famicom	Included?	Automatic	RCA	Clips 300Ω and 70Ω	Bare wire	New Famicom model uses RF adapter with proprietary plug.
1983-10-??	Casio PV-1000	Included	Manual	RCA	Clips 300Ω and 70Ω	Clips	None.
1985-03-??	PCjr	Included	Manual	Proprietary	Clips	Clips	RCA composite video and mono audio.
1985-10-18	Nintendo Entertainment System	Included	Automatic	RCA	Coaxial	Coaxial	RCA composite video and mono audio. NES-101 model only has RF.
1985-10-20	Sega Mark III	Included?	?	?	?	?	?
1986-10-??	Master System	Included	Automatic	RCA	Coaxial	Coaxial	DIN 5 composite video and mono audio. Master System II only has RF.
1986-05-??	Atari 7800	Included	Manual	RCA	Clips	Clips
1987-06-??	Master System (PAL)	Included	Automatic	RCA	Coaxial	Coaxial	?
1987-10-30	PC-Engine	Included	Automatic	RCA	Clips 300Ω and 70Ω	Bare wire
1988-10-29	Mega Drive	Included	?	?	?	?	?
1988-08-14	Genesis	Included	Automatic	RCA	Coaxial	Coaxial	DIN 8 composite video and mono audio. PAL Mega Drive is the same. Model II and 3 use a mini-DIN 9.
1989-08-29	TurboGrafx-16	Included	Automatic	RCA	Coaxial	Coaxial	RCA composite video and stereo audio.
1990-11-21	Super Famicom	Included?	Automatic	RCA	Coaxial	Bare wire	Later model used the proprietary port and didn't have an antenna input.
1991-06-18	Neo-Geo AES	External	Manual	DIN 5	Coaxial	Coaxial	DIN 5 composite video and mono audio.
1991-08-23	Super Nintendo Entertainment System	Included	Automatic	RCA	Coaxial	Coaxial	Proprietary RCA composite video and stereo audio. RF adapter is identical to NES.
1993-10-04	Panasonic FZ-1	Included	Automatic	RCA	RCA	Coaxial	RCA composite video and stereo audio and S-video.
1993-11-23	Jaguar	Included?	Automatic	RCA	Coaxial	Coaxial	Proprietary composite or S-video.
1994-09-09	Neo-Geo CD	External	?	?	?	?	RCA composite video and stereo audio, DIN 5 composite, and S-video.
1994-11-11	Panasonic FZ-10	Included	Automatic	RCA	RCA	Coaxial	RCA composite video and stereo audio and S-video.
1994-11-22	Saturn	External	Automatic	Proprietary Mini-DIN 10	Coaxial	Coaxial	Proprietary Mini-DIN 10 outputs to RCA composite video stereo audio and S-video.
1994-12-03	PlayStation	External	Automatic	Proprietary	Coaxial	Coaxial	Proprietary composite video and stereo audio and RCA composite video and stereo audio. Later models removed RCA plugs.
1994-??-??	Genesis CDX	External?	?	?	?	?	DIN 5 composite video and mono audio.
1996-06-23	Nintendo 64	External	Automatic	Proprietary	None	Coaxial	Proprietary composite video and stereo audio.
1998-11-27	Dreamcast	External	Automatic	Proprietary	Coaxial	Coaxial	Proprietary composite video and stereo audio.
2001-09-14	GameCube	External	Automatic	Proprietary	Coaxial	Coaxial	Proprietary composite video and stereo audio and proprietary component video and stereo audio.
2001-11-15	Xbox	External	Automatic	Proprietary	Coaxial	Coaxial	Proprietary composite video and stereo audio and proprietary component video and stereo audio.