You’ve seen them your whole life. Metal antennas that kind of look like a bow tie. Most likely your first experience with them was as a clip-on attachment to a very old antenna. They looked like this:
This is the classic bow-tie antenna, and depending on your age it may being back fond memories. It also may just make you feel old.
The bowtie antenna is also called a cat’s whisker antenna, especially if the antenna is a “X” shape rather than the bowtie shape. Both antennas are technically the same. The metal bar that “closes” the bowtie is there for strength, not for reception.
The solid history behind the bowtie
The bowtie antenna is a variation of the “folded dipole” which was one of the first antenna types invented. As early as the 1880s, radio pioneers realized two things:
- The size of an antenna should be an even multiple or fraction of the frequency you’re trying to receive.
- Placing the antenna diagonally instead of horizontally makes it capable of getting a wider range of frequencies.
Both of these came into play early in the development of TV. In the US, there were originally 13 channels allocated to TV, numbered 1 through 13. Channel 1 went away fairly early in the process. Just as early, TV broadcasters realized there was a need for far more than 12 channels.
TV in the 20th century was hard to do!
Back in the early days of TV, the technology used for TV broadcasting was really not that good. Broadcasting tech was so bad that the government put in rules to make sure that TV channels didn’t interfere with each other. If your city broadcast on channel 8, no other city that bordered yours could broadcast on channels 7 or 9. That’s just an example, but imagine building a national channel map trying to fit all those pieces together! With cities all over the country putting up TV stations, it was hard to make sure they all “got along.”
The answer was “UHF.” The US government allocated a whole new block of frequencies from 470-890MHz for television broadcasts. It was called “UHF” or “Ultra High Frequency.” This term was used for any broadcasting between 300MHz and 3,000MHz so it wasn’t really accurate. But it was a spiffy marketing term and it stuck.
Bowties and UHF: A perfect match
The bowtie antenna is a perfect match for the needs of UHF reception. The UHF waves are smaller, meaning the antenna can be smaller. The diagonally shaped elements mean the entire range comes in nice and clear. Also, making a bowtie antenna is fairly easy and inexpensive.
After 2009, about 90% of TV broadcasting moved to the UHF band making it easier than ever to get a lot of TV channels. Because all TV was now digital, a lot of those 20th century restrictions came off and you can have channels right next to each other with no problems.
Because you don’t need empty channels between each broadcast channel, the number of broadcast frequencies have dropped over time. While there were once 82 available channels, there are now 50 and very soon that number will drop to 35 in order to make room for more cell towers and cell data.
Don’t worry, the good old bowtie antenna will still work as well as it always has.
If you’re looking for a new antenna, check out the great selection at Solid Signal!