You may have trouble hooking up your DVD player if you have an old TV.A yellow RCA video output is one of the things that most DVD players have.Older TVs have a cable input.
Step 1: Purchase a connecting cable.
The output of your DVD player can be converted into a signal that can travel over the cable.Radio Shack and eBay have such cables.
Step 2: The output of your DVD player should be connected to the RF modulator and the TV.
Step 3: You can choose whether the image is displayed on channel 3 or channel 4.