Broadcasting Frequencies Used By TV Aerial, Radio & Satellite

June 10, 2019
by
Tom

TV Aerial & Satellite Frequencies Used For Terrestrial TV/ Radio & Satellite

 

If you are wondering what frequencies are used for TV & radio or do not know your VHF from your UHF, read this blog for all the information that you need. In this article I will discuss all the common frequencies that are used for terrestrial TV & radio services as well as the satellite frequencies which are used for satellite TV services like Sky & Freesat. I will also discuss some of frequency bands that are used by other services like mobile broadband and Tetra than can interfere with your TV signal and cause TV pixelation, so it’s important to know about these too.

 

Hertz (HZ), Kilohertz (KHZ), Megahertz (MHZ) & Gigahertz (GHZ)

Before I discuss the actual frequencies that are used for TV & radio services it’s important to have at least a basic understanding of frequency and how this is measured. TV signals are broadcast on radio waves which typically operate below 1Ghz for TV aerial services and around 12Ghz for satellite TV services. But what does this mean?

 

An Alternative current (AC) waveform you may already be familiar with. It rotates between a charge either positive or negative gradually growing stronger until it reaches it’s peak measurement. At which point it begins it’s journey back growing lower in charge until it reaches the neutral point or zero charge, then the wave performs the exact opposite process in the alternative positive/ negative charge until it reaches the zero charge point again. The amount of times it does this in a second is referred to as Hertz which stands for cycles per second, commonly abbreviated to Hz. The AC electrical supply in the UK is 50 Hz but other countries like the USA use 60 Hz. Although these Extremely Low Frequencies (ELF) are suitable for carrying power they are not suitable for numerous reasons of carrying information required for TV & radio signals which instead use Very High Frequency & Ultra High Frequency. I will come on to this a bit more later.

 

To understand the difference between Hz, Khz, Mhz & Ghz it really helps to understand the prefixes that are used for measurements. There are more that are higher, lower and in between but this will give you a good basis to start with:

Tera – Trillion

Giga – Billion

Mega – Million

Kilo – Thousand

Milli – Thousandth

Micro – Millionth

Nano- Billionth

Pico – Trillionth

The frequency ranges that concern us for terrestrial TV/Radio & satellite are in the kilohertz, megahertz & gigahertz ranges. You can see from the above that kilo-hertz means one thousand hertz, mega-hertz means one million hertz & giga-hertz means one billion hertz. So if something is broadcasting on 608Mhz which is an approximate centre frequency in the UHF, this means that in every second the signal is rotating between positive & negative charge six hundred and eight million times!

 

Frequency & Wavelength

As frequency raises the wavelength shortens. This means that the lower the frequency that larger the receiving antenna needs to be. The elements or dipole that are designed to receive a signal need to be the correct wavelength and spacing to be able to pick up that frequency. This is in essence the basics of how an aerial works. The designs of aerials that people are most familiar with are TV aerials, FM & DAB aerials. Of the three, the largest of these would be the FM antenna as FM is broadcast on the lowest frequency, followed by DAB and then TV aerials.

 

A good reference point for this is 300Mhz. I choose 300Mhz despite it being between DAB and terrestrial TV services as it has a 1 metre wavelength. Receiving antennas should have an element size of half a metre as to use one metre would mean that the antenna would pick up both positive and negative charged signals at the same time which would cancel them out. FM and DAB aerials would both have larger elements than this as they both use a lower frequency. If you wish to install a higher gain directional model of one of these the antennas themselves can be very large. AM radio again uses a much lower frequency band of 535khz – 1605khz would require a very, very large antenna. Believe it or not there are high gain versions of these and the antennas are absolutely massive! Not the sort of thing that you could install on your chimney stack and certainly not the sort of thing that is going to make you popular with the neighbours.

 

On the flip side of this as you get into the higher frequencies like are used for satellite TV, radio, internet and communications it becomes impractical to use a traditional aerial type design as the wavelengths become so short, satellite dishes are used instead.

 

Ultra-High Frequency (UHF) – 300Mhz – 3Ghz

For TV aerial reception and terrestrial TV services the Ultra high frequency (UHF) band is used. The UHF is the frequency band between 300Mhz-3Ghz, within this band we have the digital TV signals and the satellite Intermediate frequency band. As well as a WIFI frequency and interfering sources like mobile broadband and Tetra.

 

Digital TV (Freeview) Frequencies – 470Mhz – 800Mhz (Future 700Mhz)

With regards to TV aerial reception for digital TV services is 470-850Mhz. TV signals used to occupy the whole of this frequency range in the old analogue days but since the digital switch-over and greater number of services can be delivered using far less bandwidth. This meant that the governments could sell off a proportion of it, the 800Mhz range for 4G mobile broadband services. Going forward there is also a 700Mhz clearance which will be used for fifth generation devices & 5G meaning that the effective frequency range will only be 470Mhz- 700Mhz.

For TV aerial reception you will need an antenna that can pick up within this frequency range. Some aerials will only pick up a section of this frequency band. These are called grouped aerials and are good for maximising signal strength and minimising the pick up of out of band signals which can cause problems with your TV reception.

In the UK the digital TV service that can be received through this frequency range is called Freeview and is compatible with BT Vision, Freeview Play, Freetime & Youview to name a few. In Ireland the equivalent of Freeview is called Soarview.

 

TV Aerial Frequency Bands

The part of the UHF that is used for digital TV is split into 47 UHF channels each 8Mhz wide. Separate groupings of frequencies have been created within this that form ‘Groups’ or ‘Bands’. Below are the aerial groups past and present that you should be familiar with. Grouped aerials exist that are designed to maximise the signal strength and out of band interference but are less common these days. Below are the TV aerial groups, the frequencies and UHF channels they cover, and the corresponding colour associated with that aerial band.

Group A – Red – UHF Channels 21-37 – 470-606Mhz

Group B – Yellow – UHF Channels 35-53 – 582- 734Mhz

Group C/D – Green –UHF Channels 48-68 – 686Mhz – 854Mhz

Wideband (Old) – Black– UHF Channels 21-69 – 470-854Mhz

Group E – Brown – UHF Channels 35-68 – 582-854Mhz

Group K – Grey – UHF Channels 21-48 – 470-686Mhz

Wideband LTE (current) T Band – Black- UHF Channels 21-60 - 470-790Mhz 

 

Very High Frequency (VHF) – 30Mhz – 300Mhz

The Very High Frequency range used to be used for terrestrial TV services once upon a time when there was only a few analogue channels that can be used. These days the VHF is used for FM and DAB radio broadcasts.

 

FM Radio Frequency Band – 88Mhz – 108Mhz

FM radio uses a frequency band between 88Mhz-108Mhz. You will already be familiar with having to tune in your radio/ car radio and switching between radio stations.

 

DAB Frequency Band – 215Mhz-230Mhz

In the UK DAB & DAB+ radio is broadcast between 215Mhz-230Mhz. Most DAB radios have their own aerial but the good ones allow for the connection of an external aerial for better reception. 

Satellite TV Frequencies

There are few frequencies that are important to know about with regards to satellite TV reception. The main two for most satellite TV services for things like Sky & Freesat reception are the KU band and the satellite Intermediate Frequency (IF) band. I will come to the difference in a moment but we also have the satellite KA band and the satellite C band.

 

Satellite KU Band Downlink – 10.7Ghz – 12.75Ghz

The satellite signals that are used for satellite TV services in the UK like Freesat & Sky are broadcast in the satellite KU band downlink. Other countries around the world also use this for their satellite TV. For example Fransat/ TNTSat in France, Tivusat in Italy, Turksat in Turkey etc. There is a full 2Ghz of potential bandwidth here which is why you get more TV services over satellite than you can a terrestrial TV.

 

Satellite Intermediate Frequency (IF) Band – 950Mhz –2150Mhz

As the coaxial cable that connects to your satellite dish cannot handle the frequencies that are being broadcast from the satellite KU band. The satellite LNB oscillates down the transmitting frequencies to the satellite intermediate frequency band of 950Mhz- 2150Mhz. In reality coaxial cables are not suitable for carrying frequencies above 3Ghz as the signal losses would be too great. The IF band is just above the frequencies used for terrestrial TV. As these are different frequencies TV aerial and satellite signals can be combined onto the same coaxial cable with diplexers, triplexers etc.

 

Sky Q Wideband LNB IF Band – 300Mhz-2150Mhz

I have included this here as it’s important to know the Intermediate frequency used by a Sky Q wideband LNB. As there is no switching on the wideband LNB extra bandwidth is provided by sending the vertical and horizontal polarised signals down different cables from the wideband LNB and also by oscillating the signal down as low as 300Mhz. You can see from earlier in the blog that this is the beginning of the UHF and also directly on top of the UHF frequencies that are used for terrestrial TV services. The downside of this means that a Sky Q wideband LNB and terrestrial aerial signals can not be combined on to the same cable. If you needed to be able to do this you would need to convert the satellite signals to dSCR signals and then set the Sky Q box into single feed mode.

 

Satellite KA Band 17.7Ghz – 20.2Ghz

Another band that is used for satellite services is the satellite KA band. This is most commonly used satellite broadband services like Tooway & SES broadband, but is also used in other countries like Ireland for their Soarsat service, when an acceptable Soarview signal can not be achieved. Owing to the higher frequencies used than traditional satellite TV services in the KU band, dish alignments have to be even more accurate you obtain a good signal.

 

C Band Satellite

I have included this in here as some countries use it like in the USA I believe. C Band satellite operates around 3-4Ghz. I can honestly admit that I have never used the satellite C band is my 13 years installing satellite dishes as it’s very rare in the UK. Owing to the lower frequencies C band satellites are far larger than satellite dishes associated with most satellite TV services.

 

Common TV Interference Frequencies

There are some frequencies and technologies that you should be aware of, these could cause your TV not too work or your satellite dish not to work also when they reach above a certain strength and are known to overload TV tuners and amplifiers.

 

Tetra – 395Mhz

Tetra is a telecommunications system used to the emergency services like the police, ambulance and fire service. It uses a part of the spectrum that is illegal to tune into for obvious reasons, but this doesn’t mean that it can’t be picked up with a TV aerial as it’s just below the frequencies that are used for terrestrial digital TV, especially when you’re near a Tetra transmitter. Tetra operates at 395Mhz and most TV equipment is designed to automatically filter this out.

 

4G – 800Mhz

4G mobile broadband uses a few different frequencies depending on what provider is delivering the service. These are 800Mhz, 1800Mhz, 2600Mhz.The frequency that we are most concerned with as TV aerial installers is 4G in the 800Mhz range. This is because it is the one most likely to cause disruption to your TV service. 4G in the 800Mhz range prior to being used for 4G was bandwidth for TV services. Once the digital switch-over was completed and more services could be fit is less space (bandwidth). Frequencies above 800Mhz were auctioned off the mobile phone operators. The problem with this frequency band is how close it is to Freeview signals. 4G can interfere with TV signals as most old aerials are designed to pick up this frequency, add the fact that most old amplifiers also amplify this frequency the signal can become too strong overload TV tuners and the distribution equipment itself. In recent years there have been huge upgrades to the 4G infrastructure meaning that 4G interference is actually very common. Fortunately going forward most new aerials, amplifiers and distribution equipment have 4G filters built in and separate 4G filters can also be purchased.

 

For the eagle eyed among you, some of you will also notice that 4G in the 1800Mhz region could also interfere with your satellite signals on the sat IF band. This is possible though much less common owing to the way satellite dishes are aligned and the way they receive the signal. As satellite signal don’t work with inferior single screened coaxial cables, only double screened will do. It’s unlikely that the interference will make its way onto the cable.

 

5G – 700Mhz

At the time of writing this hasn’t yet happened yet as they are still in the process in moving digital TV off the 700Mhz band like they did previously with 4G on 800Mhz band. But once complete it looks likely 700Mhz will go to 5G. This isn’t the only frequency band that 5G will be using as it will be using loads including millimetre wave frequencies of 30Ghz and beyond. This again has the potential to cause the exact same problems as 4G has and going forward new aerials and amplifiers will start to reject these frequencies. I have already started installing K band aerials where possible which are not designed to pick up these frequencies, but many people will also need 5G filters on their aerials. To be honest I’m not looking to 5G for numerous reasons, but I appreciate that this isn’t the place to discuss this any further.

 

WIFI Frequencies - 2.4Ghz & 5Ghz

These don’t regularly cause problems with TV reception,although they can if your broadband router is installed too close to your TV equipment. There are currently two frequencies that are used for WIFI, these are 2.4Ghz and 5Ghz. Most new broadband routers transmit of both these frequencies, If you were wondering which one is best. 5Ghz can transmit more data but is more affected by walls etc and can not travel as far distance in which case 2.4Ghz is more suitable. The 2.4Ghz range is also very full up with many devices operating in the range, especially if you live in a built up area you may be better off using 5Ghz in these situations.

 

Aerial & Sat Frequency Questions

If you have any questions or would like to leave a comment on the blog. Please do so by leaving a comment in the blog comment section below. This is the only way that you will receive a response. Our telephone lines are reserved for customers only and we only serve Sussex and parts of Kent. Please do fill not fill out our website contact forms or e-mail. Again these are reserved for customers only and I do not have the time to deal with every enquiry that comes in individually. By posting your comment in the blog comment section below it gives me a central location to deal with all the questions I get asked plus everyone reading the blog will get the benefit of the question asked and the answer given. If you do fill out the website contact forms ore-mail you will either not receive a response or you will receive one asking you to post your question in the blog comment section of the blog that you have read. Anyway I hoped that this article has helped you on TV/ SAT frequencies for Sky, Freeview & Freesat.

 

Until next time,

Tom

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