Will installing an amplifier or enhancer improve your TV antenna? The short answer to this is that it may or may not be. For long answers, continuing reading should help you determine if you need a TV antenna amplifier or signal "enhancer."
You may hear "amp not working", which is incorrect. When used at the right time and place, they absolutely work. Large public TV systems and systems connected to many TVs will rely on amplifiers to boost the signal so it can be distributed to many TVs, not uncommon in today's world of homes with TVs in most rooms.
Amplifiers play a vital role in keeping the signal at an acceptable strength through your TV antenna system. Just saying there is a time and place for antenna amplifiers and signal boosters, plugging them into a TV with poor reception won't magically produce a reliable signal. If so, all aerial installers and engineers do. It's certainly easier to do than climb over roofs, up ladders, and through attics.
An amplifier cannot create a signal where no other signal exists, nor can it simply make an unreliable signal reliable. Amplifiers should only be added to TV systems to overcome signal loss associated with coaxial cable resistance and signal loss due to splitting the TV signal to multiple TVs. So if your antenna is sending out an otherwise good signal, and because of the length of the cable or the type of cable, the coax is lost before it reaches your TV. Then a TV antenna booster will help, but it depends a lot on where you install your TV signal booster. This is a working scenario with TV signal strength, and it's worth noting that the minimum recommended signal strength for Freeview reception is 50dB, and we think ideally at least 55 dB.
Case 1: the Amplifier Is Installed Behind the TV. (Wrong Way)
TV antenna = 60dB
Coaxial cable, signal loss -25dB = 35dB
TV antenna amplifier + 15dB = 50dB
In this case, a TV signal booster has been installed behind the TV. The antenna itself provides a good signal strength of 60dB. For whatever reason, the connecting cable between the TV antenna and the TV receiver loses an unusual amount of signal, which is not uncommon with very long cables, cables that are in poor condition, or single-shielded coaxial cables, so A 60dB signal leaving the antenna is now 35dB on the TV. A TV antenna amplifier is mounted behind the TV, which itself has 15dB of gain and provides an acceptable 50dB signal strength.
Scenario 2: the Amplifier Is Installed Near the Antenna. (Right Way)
TV antenna = 60dB
Short cable length signal loss - 2dB = 58dB
TV air amplifier +15dB=73dB
Coaxial cable, signal loss – 23dB = 50dB
In Option 2, the signal booster is installed near the antenna end of the TV system. You can see that with this method, the signal is amplified before it is allowed to fall below the minimum strength or become weaker. This method will far outperform Option 1 in terms of TV reception and performance because you are carrying almost all the signal from the antenna throughout the TV system, something an amplifier cannot replicate.
And in the scene, you're only sending 35dB of the signal to the TV. However, if the signal is too weak to get to the TV, the amplifier will make the signal slightly better. That's because the TV itself adds its own noise figure to the signal as it processes it and sends it stronger, albeit the wrong way, which helps it drive all of the TV's parts.
Signal Amplifier Overcoming Splitting Loss
If multiple TVs are connected to a single antenna, there will be signal loss when the TV signal is split. Unless you physically disconnect one TV to connect another, it doesn't matter if all TVs are on at the same time, you lose signal every time you split the signal. This would be the perfect time to introduce a TV antenna amplifier.
Below are the associated losses using a good quality passive signal splitter on the frequencies used by TV and Freeview (UHF - 470-806Mhz) Note that there are other factors that can affect the amount of signal lost in a splitter such as the quality of the splitter temperature:
2-way splitter - 4dB
3-way splitter - 6dB
4-way splitter - 8dB
6-way splitter - 10dB
8-way splitter - 12dB
It's best to err on the side of caution when doing your calculations, so I recommend adding a few dB to each of these losses so your signal levels have little room to move. This is another scenario where splitters are introduced.
Scenario 3 - Distributing TV Signal to 8 TVs (Wrong Way)
TV antenna – 55dB
Short coaxial cable, signal loss - 1dB = 54dB
8-way splitter, signal loss - 12dB = 42dB
Coax to TV, signal loss - 2dB = 40dB
You can see above that the signal from the antenna works well when fed to both TVs with coaxial cables of similar length, condition, and quality. The introduction of an 8-way splitter to feed the required number of TV points is the immediate cause of a weak TV signal, which will most likely result in poor TV reception.