You use a digital UHF modulator to convert video and audio signals into HF signals. Since a TV set recognizes these signals, you can use the digital UHF modulator to view your video recordings on your TV screen at home.You connect your camera to the digital UHF modulator at the video input and audio input (cinch). Connect the HF output with the antenna input of your TV set. Alternatively, you can use a 2-way or 3-way adapter to feed HF signals into larger antenna systems (e.g., apartment building with several flats). The modulator can be set to the UHF channels 14-69 or the cable/satellite channels 65-135 (except channels 95-99). Programming is easy with up and down channel selection buttons on the front of the device. Its compact construction makes the digital UHF modulator perfect for integration in a outdoor camera housing. With your camera installed at the front door, you can use a digital UHF modulator in combination with your TV to see who is at the door.