What Is an RF Modulator Used For?

By Fred Decker

Outmoded home electronics still have a lot of entertainment potential, from vintage video game systems and VCRs, to elderly television sets. Getting them to work together can be an interesting exercise in nostalgia, often requiring the use of oddball pieces of equipment such as RF modulators. These were common in the 1980s and early 1990s, permitting the use of newer technology with older television sets.

The Back of the Set

Modern televisions can accept signals from a large number of differing types of equipment, but older sets are much simpler. Most have only one or two types of simple inputs. The oldest models have a pair of screw terminals, designed to accept the 300-ohm signal from an external antenna. Televisions from the 1970s and 1980s typically added a round, threaded 75-ohm connection known as an "F-connector," though most consumers know it simply as a cable-TV connection. As new forms of electronics came onto the market, those basic connections quickly became outmoded.

A/V Connections

Newer devices, such as VCRs and the early video game systems, began to separate out the audio and video signals for better sound and picture quality. If your TV set had the corresponding inputs, you could connect them with a simple patch cord. However, if all you had was a cable connection or antenna terminals, you needed an additional piece of equipment to help the device communicate with the TV. This device, the RF modulator, combined the audio and video signals back together in a form your TV could accept.

Using an RF Modulator

Although the product has mostly disappeared from the marketplace, used RF modulators are still widely available online, and can be found at thrift stores and yard sales. Typically, they provide a set of audio/video inputs for your game system or DVD player, and newer versions might also include an S-video input. The output is a short piece of cable with an F-connector, designed to screw to the back of your TV. Slide the switch on your RF modulator to either the channel 3 or channel 4 setting, then turn on your TV and tune it to that channel. You should see the signal from your video game, camcorder, VCR or DVD player.

A Few Extra Adaptors

Depending on the equipment you connect, you might need a few extra adaptors. For example, if your TV has only screw terminals for an antenna, you'll need a small "pigtail" adaptor that screws into the RF modulator's F-connector and provides screw connectors at the other end. Most RF modulators only have one input for audio, so if your source provides left and right stereo signals you'll need a Y-adaptor to combine them into one connection.