Engineers could use the frequencies between 88 MHz and 174 MHz for 13 channels of programming and begin channel 14 at 216 MHz. In the CATV position the switch tells the tuner to start at 88 MHz and go straight up in 6 MHz slices, with no break. While we're on the subject of tuning, it's worth considering why CATV systems don't use the same frequencies for stations broadcasting on channels 1 to 6 that those stations use to broadcast over the airwaves. Cable equipment is designed to shield the signals carried on the cable from outside interference, and televisions are designed to accept signals only from the point of connection to the cable or antenna, but interference can still enter the system, especially at connectors. When the interference comes from the same channel that's carried on the cable, there is a problem because of the difference in broadcast speed between the two signals.
Radio signals travel through the air at a speed very close to the speed of light.
In a coaxial cable like the one that brings CATV signals to your house, radio signals travel at about two-thirds the speed of light. Inc. All rights reserved. Simply register for a free Postbox in the country where your merchant is located.