Wrong, @makaiguy . @The Atari 2600 and ALL home computer and video game consoles (with a few exceptions, i.e., the Apple II series) had a built in RF modulator, including MY first computer, the Tandy Radio Shack TRS-80 Color Computer (26-3002), which used a Motorola MC1372 chip for the RF modulation to interface the MC6847 VDG to the TV.
However, to the OP, this is a tip I learned from the Malted Media Productions CoCo Mailing List (run by Dennis Báthory Kitsz, a prominent figure in the CoCo and TRS-80 Model I communities):
Your Atari 2600 (if it's a real Atari VCS, made by Warner Communications, NOT the AtGames clone) uses a 75-ohm coaxial connection to a switch. GET RID OF THE SWITCH. Even though it was required back then so the device could get FCC approval under Part 15 guidelines back in the late 1970s and 80s as a Type I TV Attachment, but the FCC relaxed that recently.
You have to go on Amazon and get a female RCA jack to Male F adapter. Back then, you *could* just drive to the Radio Shack and get the adapter for about $2 but Radio Shack ain't around anymore.
Connect the wire that went to the TV/Game switch to the adapter. Screw the F connector to the TV.
Then, at the Home screen, press the (*) Star button while the "Live TV" option is highlighted, then scan for channels.
Pay attention to the first screen. It will ask if Channels 3 and 4 are needed for a VCR or similar. Select "Yes, channels 3 and 4 are needed".
Hope this helps.
