How Television Transmission Works?

TV Transmission Basics

1. Television transmissions are signals that come into your home to display an image on your TV. These signals can be sent over the air, through an antenna or satellite dish, or through a network of cables, as with cable television. These signals are converted to images before they are displayed on your screen.

Differences in Over the Air Transmissions

2. Over the air transmissions are usually radio signals. Antenna signals, such as UHF and VHF, and satellite signals are sent over different parts of the broadcasting spectrum, which is also used by cell phones, AM and FM frequencies and walkie-talkies. The difference between antenna and satellite signals is the frequency they transmit on, and the technology used to send them.

Antenna Signals

3. Antenna signals are sent from a radio broadcast tower, just like AM or FM signals. This is why many handheld radios can intercept antenna TV signals and play the sound. Antennas must be within range of the closest broadcast tower to receive a signal strong enough for display.

Satellite Signals

4. Satellite signals are transmitted from the broadcaster to the satellite, where they are blanket broadcast to any satellite dish capable of receiving them. Satellites are not limited by range, but by line sight, so a receiving dish must have a clear view of the satellite in the sky.

Cable Signals

5. Cable transmissions are converted to electrical impulses. The impulses can travel much further than antenna signals, but will lose integrity after long distances. They are over intercepted by stations that will strengthen the signal before retransmitting it to your home.

Conversion

6. Once the signal has reached your home, it is converted so you can view it on your screen. Satellite signals require special devices, known as receivers, to do this conversion. Analog cable signals sometimes need a special receiving unit, but nearly all modern TVs are considered "cable ready," meaning they have the receiving unit built in. Any analog antenna signal can be displayed without special equipment, and TVs that are not "digital ready" will require a digital to analog converter box to properly display.