It’s called a radome. Even though it’s not a dome, it doesn’t matter. The name is the same.
What is a radome?
Radomes are used in all sorts of antennas to provide both weatherproofing and some level of attractiveness. The weatherproofing part came first, the style came later.
Radomes were first used in ships at sea during the second World War. The term is a contraction of the words “radar dome,” and radar antennas were the first to need that sort of protection. Before radar, marine antennas were just painted. This probably diminished their effectiveness but not a lot. However, radar created a whole new set of problems.
OK then, what is radar?
Radar, or RADAR as it was originally called, is a system of RAdio Detection And Ranging. It combines several technologies that were just starting to be used in the 1940s.
Radio imaging was an offshoot of SONAR (SOund Detection And Ranging.) In either case you are sending a signal out and waiting until it echoes back. Then you count the amount of time it took and you can figure out how far away something is. It’s a lot harder to do with radio waves because they move faster, but it’s a lot more accurate. That’s why radio imaging had to wait for two other technologies: electronics and television.
Electronic computing didn’t exist before the second World War. Using amplifiers, gates and electron paths to perform complex calculations is a lot faster than using gears or (perish the thought) humans. However it took a lot of science to get us there. With electronic computers, distances could be accurately measured even in millionths of a second. It could all be done in real time, which is important. Electronic timing devices could measure tiny bits of time and electronic calculators could do the tough math.
The last piece of the puzzle is a way to show a radar operator what’s going on. The electronic television screen can put dots anywhere and this is perfect for creating a visual map of what’s all around you. It sounds so obvious today, but 80 years ago this was all pretty fancy stuff.
The problem with radar
Unlike regular broadcasting and reception, a radar antenna needs to keep spinning. That means the gears and electronics need to be kept clean and free from corrosion.
Radomes were invented to shield a radar installation from the elements. They also helped mask the movement of the antenna which might be seen from a long distance.
Today’s marine satellite dishes use radomes much the way that old radar installations did. The radome covers the antenna and keeps dirt and water away from the gears and electronics.
In the case of TV antennas, radomes provide some visual style and they also allow the antennas inside to be more delicate. Using more plastic and less aluminum means the antenna can be less expensive to make.
If you’re looking for a stylish TV antenna with a white or black radome, look no further than the excellent selection you’ll find now at Solid Signal.