Television: RF Modulator Buyer’s Guide
However, you may not actually need an RF modulator to do this. If your TV already has RCA input jacks, you can directly connect the device to your TV and set it to the input channel. Also, some video cassette recorders have a built-in RF modulator. Make sure that the device actually needs an RF modulator to connect to your TV – refer to the device’s manual or try to find it on the internet if possible.
If you are trying to connect a computer with an RCA jack for video output (usually pre-1992) to your television, it may or may not need an RF modulator. Some computers, like the Tandy 1000 series, do require an RF modulator or RCA input jacks on the TV. Others, such as the Commodore 64, don’t need an RF modulator and won’t work with RCA input jacks. Computers of the 2nd type should instead be connected to a TV/computer switchbox (sometimes referred to as a “TV/game switchbox”), which then connects to the television. The same is true for some video games systems like the Atari 2600.
After you are sure that you need an RF modulator, consider some of the features you might want to look for in one. Some have s-video support, which is useful if you have a device with this type of video output. While many RF modulators (like the Radio Shack 15-1214) have a regular built-in power cord, others use a larger AC adapter. An RF modulator with a normal power cord is less likely to block other outlets it isn’t using, as adapters sometimes do.
Because a television which needs an RF modulator doesn’t have an input channel, the modulator uses a regular TV channel to provide the modulated video and/or sound. Most of them have a switch which lets you select VHF channel three or four. Unless there are strong local TV stations broadcasting on both channels three and four, this will probably be fine. If you do receive strong stations on both channels (and/or very strong adjacent stations on ch. 2 and 5) with your antenna/cable/satellite disconnected, you might want to look for an RF modulator which uses UHF (14-68) channels instead. Try searching for “UHF modulator” on eBay to find these.
If your television has 300 ohm antenna screws rather than a 75 ohm cable-style jack, you will probably need an additional adapter to connect the RF modulator to your television. This adapter is called a 75-300ohm matching transformer, and converts its cable wire to two wires which can be screwed in on the back of your TV.
While they can be found at some other types of stores and websites, the easiest places to find RF modulators are at Radio Shack stores or eBay.com. Radio Shack sells them for about $20, or you can find them new & used for approximately $7-$25 on eBay. RF modulators can also be found at yard sales, thrift shops, or used merchandise stores occasionally. They have been manufactured by a variety of brands, including Jensen, Archer, and Channel Master.