Do Cable TV Signal Boosters and TV Signal Amplifiers Work?
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.
When Is It a Good Idea to Install a TV Signal Booster?
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.
Scenario 4 - Distributing the TV Signal to 8 TVs (the Correct Way)
TV antenna – 55dB
Short coaxial cable, signal loss - 1dB = 54dB
TV antenna amplifier - signal gain +15dB = 69dB
8-Way Splitter - signal loss -12dB = 57dB
Coaxial cable to the TV, signal loss -2dB = 55dB
Do it the right way. Amplification stages are added before the signal loss associated with the 8-way splitter. This has completely overcome it, the signal gain on the amplifier is more than the signal loss on the splitter. This is not always needed, just to not allow the signal to go below the minimum. As a result, the TV now has more than enough signal to provide good and reliable reception.
There are widely available amplifiers that provide signal separation and amplification. These are called distribution amplifiers. Doing so won't necessarily provide a reliable signal though. It usually creates a cleaner install.
Mounting an Amplifier at the Antenna Side (Front End) of a TV System
An obvious disadvantage of installing a TV antenna amplifier is the need for a power source near the antenna. If you have a power outlet in the attic, that's fine, as it's usually just a short coaxial cable that connects the amp in the attic to an antenna on the chimney, or to an antenna on the wall. The antenna itself might even be in the attic. In this case, this would be perfect. However, electrical outlets with lofts are generally uncommon. In this case, you contact your local electrician to install one for you, which will obviously cost you more money.
One of the more appropriate options a TV antenna installer can make for you, though, is to install a line-powered amplifier instead of a mains amplifier, without the need for a qualified electrician. Line amps, and more commonly the most common type of line amp, the "header amp" is powered directly from the same coaxial cable that powers the TV. A small power supply unit or PSU is mounted on the overhead cable, and DC voltage (usually 5V-12V) is sent to the mast amplifier on the coaxial cable, allowing it to boost the signal.
The advantage of header amplifiers over traditional power amplifiers is that no power is required for the amplifier location, and the header amplifier itself can be very close to the antenna itself, most commonly found on antenna masts and housed in a weatherproof outer box, hence the name. This allows the signal to be amplified while it is still at its strongest, carrying the greatest amount of real signal throughout the TV system.
Conclusion - Antenna Amplifiers Do Work
All in all, if you still have any doubts at this point. TV antenna amplifiers and signal boosters really work. They can help overcome signal loss due to cable resistance and splitting the signal to multiple TVs.
However, they won't magically turn a poor or weak TV signal into a good, reliable one. But when used correctly, they can solve your signal problems.
It is best to fix TV antenna reception as passively as possible, with as little amplification as possible. So changing the antennas, aiming for peak reception, or relocating them to a better location, maybe from the attic to the roof is a better option. Also, using only the highest quality double shielded coax and shielded wall plates and high-quality flying leads where possible is a better solution than introducing unnecessary amplification.
Buy a TV Signal Amplifier from Haoze
Haoze is a professional custom antenna accessories manufacturer. Our products include TV signal amplifiers, CATV power amplifiers, CATV splitters, splitters, satellite splitters, CATV wall sockets (terminal boxes) and other high-quality CATV system accessories, Audio, and video connectors, etc. We have our own engineers, so we can design and produce products according to customers' requirements. All products are produced by automatic machines and fully tested to ensure the quality of our products. If you want to buy antenna accessories, please contact us.
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