TV Antenna Amplifier: aerial booster

TV antenna or aerial boosters are sometimes required when signals reaching the television set are low and the signal needs to be boosted at the antenna.

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Sometimes televisions need an antenna or aerial amplifier /booster. This TV antenna amplifier will enable the signal to be increased in strength so that a better signal can be viewed.

However when thinking about buying and installing an antenna amplifier / aerial booster, there are a number of points to consider so that the best antenna amplifier can be bought and installed to give a better picture and better TV reception.

TV antenna booster and 3 way splitter in a roof space
TV antenna booster splitter in a roof space

Pick the wrong antenna amplifier, or if one is not suitable for the particular circumstances, then an antenna booster or aerial amplifier can make things worse.

Get the right one working under the right circumstances will make a big difference, giving a much better picture with less pixellation and general picture disruption.

The right TV aerial booster amplifier may increase the signal strength of the received signal so that more stations are available, giving a better choice of programming

What is a TV antenna booster

A TV aerial or TV antenna booster is an amplifier that boosts the signal level of the received television signals to enable a better picture to be received.

As the name indicates a TV antenna signal booster or amplifier is a unit that amplifies the incoming signal before it enters the television itself.

The aim is that when signal levels are low, the amplifier is able to boost the signal to a sufficient level to enable a good picture to be received by the television so that it is able to give a good picture.

One of the reasons an amplifier may be needed is that if the signals are borderline good enough, then the attenuation in the coaxial feeder may mean that they are too weak to provide a good picture because the signals are closer to the background noise level in the RF sections of the television.

If the signal is amplified at the television antenna, then the amplifier has a better signal to amplify and the noise levels are kept lower.

Amplifying the signals at the television will not improve matters much because the signals may already be too low in strength as a result of the coax signal loss that the background noise levels then mean they cannot be recovered properly.

When is a TV antenna booster needed

A television antenna booster should only be used at the antenna as we have already seen. Although some boosters may be designed for use next to the television set, these are unlikely to provide a huge improvement improvement.

They are just amplifying the same signal that the television would receive and normally televisions are designed to provide a very high level of sensitivity. Just putting another amplifier next to the TV may not give any improvement.

A television antenna booster may be needed when signal levels are very low and the coax cable or feeder los can impact the signals to the degree when thee do not produce a good signal.

Normally a television will have a well designed aerial input stage and just adding another amplifier there will not provide much improvement if any and could make matters worse because it might overload the stage.

A TV antenna amplifier may also be needed when it is necessary to drive two or more televisions from the same antenna. Any antenna splitter without an amplifier will introduce loss, so having an amplifier as part of the splitter enables this loss to be overcome.

Again, the best place for the splitter amplifier is as close to the antenna as possible, but in reality this may not always be practicable of feasible, so compromises an be made, and can often pay off well.

Concept of a TV antenna booster and splitter
Concept of a TV antenna booster and splitter

The diagram above shows a TV antenna booster and splitter installed close to the antenna powering two down-leads to two separate televisions.

TV antenna booster buyers guide

There are several points to consider when buying TV antenna booster or antenna amplifier.

It is always best to take a good look at the whole television system with its antenna and the like. In this way a proper assessment of the requirement can be made.

  •   Check the antenna cable first:

Before installing a TV antenna signal booster / amplifier, it is worth checking the antenna coax cable is this has been installed for some time.

If the cable is used for an external antenna, and it has been in place for a while, it is more than likely that moisture has entered the cable. This will cause the cable to attenuate or reduce the signal strength - this attenuation occurs slowly and the incremental increase in loss will pass unnoticed until the system becomes unworkable.

It is very difficult to prevent moisture from entering the coax cable even though there is a housing on the antenna where the connection is made. Sealing the end of the coax can help prevent this moisture ingress and slow the deterioration of the cable. Even without this, sunlight and toxic gases present in the air will cause the cable to degrade over time, so periodically renewing the TV antenna installation can ensure the performance is up to the required standard.

In cases like these, installing a new booster amplifier for the television will not cure the source issue. In some instances the cable loss may be so high that even with a signal booster it will not overcome the losses in the cable. As a result, it is always good to check the cable before considering a television antenna amplifier / booster.

  •   Do you need a splitter / amplifier or booster:

In some instances it is necessary to supply more than one television from a single antenna. When this is done using a passive splitter, i.e. one without an amplifier / booster, the signal levels drops because it has to be split. To overcome this, amplifier / booster splitters can be used. The booster normally amplifies the signal to above that of the original signal, more than making up for the loss of a passive splitter.

  •   Internal or external:

Very often antenna boosters are made for internal use. They have an ordinary cable entry point and power leads. For external use a power supply is located by the TV and power transferred up the antenna coax lead.

Also the unit will be waterproof as it will need to withstand the rigours of the weather. Any moisture entering the amplifier / booster will cause damage and ultimately lead to its failure.

  •   Not too much gain:

One of the key parameters of any antenna booster / antenna amplifier is the level of gain it provides. This is typically expressed in decibels, dB. Often it may be around 10 to 12 dB, although some offer up to 20dB and more is what is best. Too much gain can overload the TV input and cause the signal to be even worse. So never put two amplifier / boosters on the same antenna.

It is possible to estimate what is needed. As a broad rule of thumb, there is a signal loss of 1 dB for every 5 metres of cable. So, a cable of 10 metres needs 2 dB gain and a cable of 20 metres needs 4 dB gain. It is surprising quite how much cable is used running the signal down from the television antenna to the set.

It is important that the TV aerial booster does not provide too much gain. This can overload the television input and provide more issues than it solves. Some television antenna boosters have an adjustable an adjustable amplifier, so it is possible to adjust the amplification to get the right level of signal.

  •   Locate the booster close to the antenna:

As described above, it is always best to locate the TV signal booster as close to the antenna as possible. It is for this reason, that if an amplifier is required for an external antenna, then it needs to be located outside close to the antenna.

External amplifiers, if they are well made and are able to last, are expensive. They are normally fitted within weatherproof boxes that have rubber gaskets, etc to prevent any weather, moisture and the like entering. They also have special fixings so that they can be attached to the mast.

However, if the amplifier fails it does mean that the amplifier will need to be retrieved and replaced and as it is likely to be inaccessible, this can be costly. It may be worth considering a higher gain antenna first.

  •   Mobile phone filter:

With digital television signals now being transmitter in most countries, it has been possible to release soem spectrum for other uses. The digital television systems are far more efficient in terms of the usage of bandwidth and signal spectrum.

Often the spectrum that has been released has been given over to use for mobile phones / mobile communications. As a result it is sometimes possible that interference may arise, especially if a mobile phone is located close to the television antenna. To help overcome this issue many modern television aerial or antenna boosters incorporate a filter to help remove these signals. Before investing in a new TV antenna booster it is worth checking that it has one of these filters if it can be a problem in your country. They may be labelled as 3G, 4G, 5G or LTE filters.

There are normally several different TV antenna boosters or TV antenna amplifiers that are available. Choosing the right one should be relatively easy, but have a look at the reviews and check how reliable they are. Also check on their performance.

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