The ABC’s of Antennas, part 3


Ladder
When going up on the roof to install an antenna, use a sturdy ladder and have a friend stand by and steady it if possible. Don’t rely on a cheap ladder that isn’t rated for your actual weight. This isn’t the time to lie about those cookies you have been sneaking… if you’re a 230-pounder don’t pretend you’re at 195 just to get a cheaper ladder.


Megahertz
A simple way to think of Megahertz is as an address. Every TV signal broadcasts on a different frequency so that they don’t cause problems with each other. For example channel 22 is at 518 megahertz (MHz) while channel 23 is at 524 megahertz. A TV antenna is designed to pick up frequences from 175 to 806 megahertz.


North
In order to aim an antenna properly, you need to know where north is. Antenna aiming is done using compass directions.


Ohm
The Ohm, usually abbreviated with the Greek letter Omega (shown above) is a measure of resistant. It’s important to use the right cable when installing an antenna. Coaxial cable should be 75Ω.


Preamplifier
A preamplifier is used on a large antenna to try to lock in distant signals, and to make sure that the signal that reaches the TV is strong enough. Preamplifiers are installed at the antenna site.