Have you ever used a TV antenna? If you haven't, that's okay; it means you're young 😊. The TV antennas I'm referring to are called over-the-air antennas, and they look like this.
Unfortunately, they aren't as common but are still very relevant; after all, they're free. People think that there are "special" antennas designed for HD (high definition), while in fact, it's the same antennas that we used to receive our "low definition." The TV stations didn't change the transmitting antennas, and we haven't changed our receiving antenna.
HD antennas are merely a marketing stunt; there is no such thing as an HD over-the-air antenna!
HD describes the quality of the audio-video being recorded and shared with the audience, and it's not about how the signal is transmitted or received. The recording devices got better, our viewing devices got better and bigger, and we'll leave it at that.
So, how is the signal broadcast to us? The signal travels on a band of a radio wave. There are different bands of radio waves (a whole subject on its own), but what we need to know is that there is a spectrum of frequencies. Frequency is measured in waves per second.
We are going to mention only two: VHF (Very High Frequency) and UHF (Ultra-High Frequency).
But wait, why am I mentioning radio frequencies and VHF/UHF bands when this blog is on HDTV? TV broadcasts are transmitted partly on VHF and partly on UHF, not the whole band, just a part of it. One of the misconceptions is that people think TV stations broadcast on the channel they identify with, for example, CBS2 on channel 2. That is not always the case; they can broadcast on channel 5 or 8.
Things changed greatly around 2012 when cellular companies paid billions of dollars to buy these channels from TV companies through the FCC (Federal Communications Commission). By doing so, it minimized the VHF/UHF spectrum of available channels for TV companies. Some TV companies completely stopped broadcasting over-the-air; others moved to another RF (Radio Frequency) channel and sacrificed the quality of reception for their viewers.
HDTV antennas are still sold in stores, but it's all a misconception and a marketing ploy, so don't be fooled. The RF (Radio Frequencies) channels allocated to TV broadcast in the US are as follows: VHF transmissions are received by your TV on channels 2 to 13, and UHF is received on channels 14 to 36.
The antenna is extremely important as each of the bands (VHF/UHF) requires a different element to optimize reception. UHF channels can be picked up by a small element antenna, typically less than 8” long, while VHF channels require a longer element antenna. The omni-directional (all directions) antenna sold in most general stores isn't ideal to receive these transmissions; in most cases, they are the bare minimum to allow you to receive something rather than nothing.
There are many intricacies to selecting the right antenna, as the two bands require different elements to optimize reception, as mentioned briefly above, but other than that, like the following: Did you know that UHF is less prone to electrical interference than VHF? However, one of the UHF disadvantages is that it requires fewer obstructions and more line of sight to receive the broadcast than VHF. Additionally, it requires more power to receive and often requires a preamp, also called an amplifier, to be installed. Finally, did you know that UHF is closer to 4G LTE and 5G frequencies, which can cause interference?
If you did, you are amazing! I didn't until I researched the subject. There are many other variables, and we haven't even mentioned the coaxial cable yet (see my other blog about them). I don't want you to be frustrated with the info or the fact that your TV doesn't work in your new location; I'm here for you to help you find a signal and improve your reception.
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