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Freeview : Do I Need a New Aerial ?   


The first question which most people ask is

"Can I get Digital reception with my present aerial ? "


Examination of the Digital Transmitters Nationwide page will tell you (amongst other things) of any change of group for your transmitter which is an essential starting point in order to answer the aforementioned question. After this it`s a matter of knowing the signal strength in your area to determine which aerial we would recommend. If your transmitter has a dedicated page on this site that is the first place you should look for the required information. The case of the Sheffield area (below) is a “worked example” of how to ascertain if you will need a new aerial or not.

 

As a “worked example” in the Sheffield area (not including those on the Chesterfield transmitter) if you used to get all five analogue programme channels perfectly then you would almost certainly get digital OK. This simple test proved that you are either on Emley Moor (which has not changed group) or you are on Sheffield/Crosspool [or Belmont] and you already have a wideband aerial potentially capable of receiving the digital broadcasts.  


One thing which needs to be stressed is the unreliability of the "Post Code Predictions of Coverage". That is only a guide and it is frequently wrong. The very idea of being able to accurately predict RF (Radio Frequency) coverage is laughable. How can they possibly know if (for example) there is a tree or high building in the path from any particular transmitter, or if the site is in an “RF dead spot” ? A site survey by a decent aerial installer is far more accurate, but (unless that includes climbing on the roof with an aerial and a Digi-meter) even that is not 100%. The only sure way to confirm Digital coverage is to change the aerial and (preferably) the down lead as well, particularly if it is "budget low-loss Co-Ax".


What is a Digital Aerial Installation ? The obvious (and correct ! ) answer is any aerial which receives a Digital signal well enough to allow reliable viewing. The word reliable cannot be over stressed because if your signal is marginal the Digital Cliff Edge can make viewing Digital a very frustrating experience, particularly when the sound mutes just at the punch line of a joke that`s taken 10 minutes to reach its denouement.......


Generally speaking a Digital TV aerial installation is one where the signal reception quality is maximised in order to minimise the effects of the Digital Cliff Edge. This may require a different group or quality of aerial, upgraded cable or wall plate, a better quality amplifier or splitter,

or nothing at all !  

And, arguably, most people fall into the latter category.

Note that since Digital Switchover (DSO) many aerials which were not “digital” before,

will now be able to pick up the Freeview signal.   

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Digital Myths


There are so many misconceptions and so much (deliberate ?) misinformation about "Digital" that we thought we should tell the unvarnished truth. Perhaps the biggest Digital myth is that it will make your TV obsolete and that is a complete fiction. You may need a Set Top Box (from around £15) but all TVs will work with a Digital  Box.

In fact, if you buy the correct box, even sets with no SCART input will operate perfectly well on Freeview.

The fact is that many unscrupulous people are trying  to make money out of the Digital Switchover as the BBC have found.

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High Definition TV  (HDTV)


High Definition TV is about more detail in the picture, and this is great when you`re watching the set from a few feet away, which is precisely the distance you`d see it from in the shop whilst the salesman tries to sell it to you. There is no doubt that HD has a better picture than standard digital and even (good) analogue but for the average size set I have my doubts about how much of the extra detail you would actually see from the normal distance which you would watch TV from. As an example, if you had a 28” TV and sat 10ft (or more) from it then most people would not see any difference in the picture over a (good) analogue 625 line resolution picture. There is no question that High Definition TV would be worthwhile if you had a screen the size of your wall but I`m unsure how many people would actually want a TV of that size. I suppose it would at least save on having to redecorate that side of the room and bearing in mind that these days anyone who doesn`t have a "House Makeover" every other month is considered abnormal (Home Makeovers, the new Rock & Roll ?, count me out....) this could save a considerable amount of time. This saved time could then be used to put in extra hours at work which would then help pay for the expensive wall sized TV you`ve just purchased, and so the circle is closed. Isn`t the symmetry of life beautiful ?

My advice is don`t bother talking to anyone or spending any time researching HDTV. Go down to the shop, try to be impartial (sub conscious influences, it looks very swish therefore it must be better....) and ask to see the set on showing a football match next to a SD TV.

Watch the picture from the same distance you would normally do so at home and then make up your own mind mind, but remember to bear in mind that (on either Freeview, Cable or Satellite) only a small percentage of all the channels will be High Definition anyway !


Originally HD on Freeview consisted of one MUX being given over entirely to HDTV, the programmes which were originally on it were then squeezed onto the other 5 MUXES. However, even using an entire MUX for HDTV only gave half a dozen HDTV channels and this was at the cost of increased compression (i.e. a worse picture) to all channels moved onto the other MUXES. Then, from Nov 13 onwards, two more  HD MUXES began to be rolled out but only to the 30 transmitters with the largest population coverages and at significantly less transmission power than the other digital channels.


NOTE !  You`ll only get a (Freeview) HD picture if either :


1  You`ve got a TV with built in HD (i.e. one purchased after Spring 2010), not an “HD ready” TV bought before that time, in which case will require an external HD Freeview box (see 2).

Many "HD Ready" TVs purchased before this date will appear not to receive any signal on the frequency that HD is being transmitted on. So, if you get good signals on the 5 other MUXES, but nothing at all on MUX3 (the HD MUX), how old is your TV ?


2  Your TV is “HD ready” and connected to your HD box via an HDMI lead and the TV is switched to the HDMI AV input. If the TV is just connected by SCART, or by the RF (i.e. through the tuner, as all distribution systems are) you should still get a picture but it won`t be in HD !


You can get HDTV through Sky though unsurprisingly the grasping Murdochs will require you to pay extra. For all that outlay not all the receivable programmes are available will actually be in HD. The actual number keeps changing so check with Sky as to the latest situation. NTL/Virgin Cable TV also do HDTV, but again not all programmes are in HD. Oh yes, and you will require different STB, at extra cost naturally, haven`t I just said that.......?  


In May 2008 the BBC (and ITV) launched a free to view satellite platform which is carrying some HDTV, but it will suffer from all the additional complication/expense involved in satellite reception.

Digital Negatives


A Digital TV picture (as in standard definition, not High Definition) is NOT superior to a good analogue picture, when it was being transmitted, obviously. In fact (and "the powers that be" are very quiet about this) it`s actually worse. Because the broadcasters want as many programme channels as possible they have sacrificed picture quality (and a robust signal) to that end. A good (I must stress that word) analogue picture took advantage of its greater bandwidth to give more detail and a "higher refresh rate" to the picture. I accept that one had to look closely at the picture (or be an expert) but a digital picture is worse, though some digital channels are worse than others, it`s down to the amount of compression used for that particular transmission. Look at the fine detail (particularly on a moving shot, a football match is a good example) and one can see it "blocking". Even more annoying, to me anyway, one can sometimes see the staccato movement associated with a low refresh rate. All the inferior picture qualities of Digital (plus a few more) are also present on LCD or Plasma Televisions.


The Digital signal is not as robust as the old analogue one. An analogue signal could be really quite poor and one still got a watchable picture. It might have been be grainy, and maybe even ghosting as well, but if Mr Rooney sent a right foot pile driver towards the top left corner of the Brazilian goal in the 2010 World Cup final (sorry, out of date, 2014 cup final, then the 2018 then the 2022 etc.....) you would see it go in, or not.

A digital signal will not degrade in the same manner. Generally you will either get (what passes for) a perfect picture, or you`ll get very annoying blocking/freezing, or you won`t get anything at all. Sods law being what it is (if you live in a marginal area) this picture loss will occur just when you really, really, don`t want it to.

Did he score ?

Did we win the World Cup ?

Of course we didn`t, what are you, a fantasist ?

Digital transmissions have in-built "error correction" (though many people feel there isn`t enough of it...) * which can overcome a certain amount of signal degradation. However, once that error correction data has been exhausted the picture has no alternative but to fail spectacularly. This is known as the "Digital Cliff Edge" and it is why one should go for the best aerial, the best cable, screened wall plates (if used), and [if required] a decent screened amp/splitter. Any one of these may (normally) only make a marginal difference, but if they keep your signals on the right side of that "cliff edge", then for what they cost, it`s an excellent investment.

To be perfectly honest you will always get the odd signal “glitch” (freezing etc) with Digital signals and that applies to Sky as well as terrestrial. All you can do is try to limit it as much as possible by maximising the quality of your signal, see graphic.


The “powers that be” keep changing the name of the MUXES, so we just refer to them as MUXES 1 to 6, as they should be anyway....

Don`t you just hate all this name changing b****x ?

Programme to MUX allocations      (For England, correct as at 30 Dec 15)


MUX 1 / BBC A =  Main BBC channels (including the BBC radio channels)


MUX 2 / D3 & 4 =  Main ITV, C4 and C5 channels + ITV2 + More 4 + E4 + Film4


MUX 3 / BBC B =  BBC1 / 2 / 3 + CBBC + ITV + C4 HDTV channels


MUX 4 / SDN =  ITV3 + CITV + Top Up TV + QVC + Bid TV + FIVE USA + Quest


MUX 5 / Arqiva A =  Dave + Sky News + Pick TV + Price Drop TV + Really + E4 plus 1


MUX 6 / Arqiva B =  Yesterday + ITV4 + Ideal World + 4Music + Al Jazeera


MUX 7 / COM 7 =  BBC4 + BBC News + CBeebies + Al Jazeera HDTV channels


MUX 8 / COM 8 =  QVC HDTV channels


For a comprehensive up to date list go to Digital UK channel listings

(England is the 1st column, Wales the 2nd, Scotland the 3rd, and N Ireland the 4th)


Notes.

The first three MUXES are known as PSBs (Public Service Broadcasting) and as such they receive higher priority in the allocation of channel space, or frequencies within a particular transmitters original group. The PSBs are the only ones broadcast by the smaller repeater transmitters (see 6 MUX transmitters). However, it should be borne in mind the three PSB MUXES contain all the “main” channels (including the main HD channels).

And let`s face it, most of the rest are either repeats, or rubbish.....


Between Nov 2013 and July 2015 things started getting even more complicated in that  2 planned (slightly lower power) HD MUXES were rolled out, but only from the 30 transmitters with the biggest population coverages. It remains to be seen how long these will be transmitted for…..

Digital TV


Note, due to the new phenomenon of MUXICAL chairs you may experience problems with certain MUXES disappearing. First try rescanning your TV / set top box, do it manually if possible.  If this fails to sort it check on transmitter work or call the reception advice phone numbers.


Also see basic digital fault finding.

Some people needed their aerial and/or downlead changing. This often mean swapping to a wideband antenna but for most people it didn`t, they got/get a perfectly good signal off their existing grouped antenna. In fact, in poor signal locations, grouped aerials actually work better anyway  Some houses are in such poor locations that they will never get decent terrestrial digital although it should get a lot better after DSO.

Unfortunately some people will have no alternative but to go down the "Freesat/Sky" route or  Cable TV but since switchover there really aren`t many people who can`t get a decent digital signal

Incidentally, I would always advise anyone with Sky to have a back up aerial. Not only will it mean you can feed any number of TVs or PVRs (capable of tuning independently) but if your LNB / Dish / STB fails you will still get Freeview. We regularly get customers phoning us up in desperation at Christmas, their Sky has stopped working and no-one can get out to repair it for 3 or 4 days.......

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Many people find the setting up/retuning of the Freeview boxes or TVs somewhat complicated, but unfortunately, the days of "tune in once then forget it" have gone because much swapping about of programmes and MUXES will happen over the years, and every time that`s done your box/TV will need retuning. In fact some PVRs also then need all the recordings re-entering.  


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In our experience Digital tuners are not the most reliable * pieces of modern technology and they aren`t really repairable either. That`s not a big deal if it`s a separate "STB" which has failed (they aren`t that expensive) but if its built into your TV then that`s a rather different story......  It used to be possible to economically repair around 80% of conventional TV`s (i.e analogue, non LCD, non Plasma, non Rear Projection) but with integrated sets it`s far lower than that, see Repairs. That`s why, whilst they were available, we advised people to buy an analogue TV and a separate set top box. Doing it that way was more flexible as well.


* The most effective way to increase the reliability of your STB (or any piece of electronics) is to keep it cool, i.e. do not place it in an enclosed area on top of a video.


Remember any TV will work with a digibox (provided the latter has an RF output) so don`t be forced to buy a new TV when you don`t have to.

Some of the oldest digiboxes and digi TVs gradually ceased to function from Summer 2008 when the broadcasters "Split NIT" network changes occurred. Note this only become apparent when the digi box was retuned, as they regularly have to be. There are also a number of models of digibox/IDTV which ceased working after switchover because the transmission mode changed, from 2K to 8K.

Remember analogue TV still exists !  Everyone who adds the signal from their Sky box (or CCTV via a modulator) to their distribution system is using analogue TV transmission/reception ! They`re both analogue signals modulated onto UHF frequencies.


Incidentally, different models of STB / TV have differing tuner sensitivities, and it`s not always the expensive ones which are the best either ! We`ve had customers tell us they`ve got significantly more reliable digital pictures by simply changing the STB.


See : Basic digital fault finding.

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Let`s be honest, nearly all of  the additional programme channels on Freeview (or Freesat) are either repeats, or they`re just crap. I know that`s a subjective opinion but I suspect most people would agree with it. Actually, come to think of it, it`s not a subjective opinion at all, most of the programmes are repeats ! (see below). And quality wise there is an inverse proportional law about TV, the more programmes there are, the worse they are. I`ll resist the temptation to give my opinion on producers who try to make their programmes more interesting by using “5 second attention span” editing, one can only assume it`s aimed at kids with attention deficit disorder.

Hold on, I`ve just realised, I haven`t been able to resist the temptation, sod it.

If they continue increasing the number of channels there will eventually come a point where it takes longer to go through the TV guide very week, than actually watch the bleedin` programmes. Whisper it quietly but there really are far more interesting things to do than watch TV, though these days “Health & Safety Bollocks” seems to try and to put the mockers on most other things......

I tried to avoid getting digital for as long as possible because the wife spent far too long watching TV  even when there were only five channels.

Let`s face it, she should be giving me more attention.

And doing more housework, obviously.

Remember, a wife isn`t just for doing the cooking.

She`s for doing the cleaning as well.

Only joking girls !


The comments on extra TV channels obviously doesn`t apply if you`re a sports or film fan,

but you won`t (generally speaking) get much of either of these on "Free to View" TV.


Quote from the Radio Times :

“ALL PROGRAMMES ON DIGITAL CHANNELS ARE REPEATS UNLESS STATED OTHERWISE”

Nuff said......


When I last checked the Radio Times no longer gives this information, not prominently anyway, but when I questioned why they said the`d look into replacing it. Time will tell.


Ahh, it`s back, for now anyway.......

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Digital Switch Over (DSO)

Digital has actually been transmitted since 1998 when it started as On Digital (remember them #1). In 2001 it was rebranded ITV Digital (remember them #2), finally becoming Freeview in 2002.

The analogue switch off took place in the UK between 2008 and 2012, and as it was turned off in each area two things happened :

First, the hundreds of smaller repeater transmitters (which up to that point had only transmitted analogue) swapped over to transmitting [only] digital.

Second, the digital power was substantially increased at the 80 original digital transmitters.

The timings were :


2008 Cumbria & Borders.

2009 SW England, Wales & NW England.

2010 West of England & N Scotland. (Note that Borders is 2008).

2011 Central Scotland, Midlands, Yorkshire & East Anglia.

2012 Ulster, NE England, London, South & SE England.


How the switchover occurred


The switch always occurred mid week (usually on a Wednesday) in order to give people time to sort out any aerial work they needed before the weekend. In almost every case analogue BBC2 was switched off first and at the same time the (low power) pre DSO MUX 1 [the main BBC channels] was switched off as well. MUX1 was then reallocated to its post DSO frequency (often that vacated by analogue BBC2) and at its new, much higher, power.

Two later the rest of the analogue channels were switched off and the other MUXES reallocated to their new frequencies at their (higher) post DSO power. There was no technical reason for this phased switchover, in fact it`d have be easier for the broadcast authorities to do it all at the same time. It was to give Joe (or Joanne) Public a chance to sort himself (or herself) out, to get a box if needed or upgrade their aerial, whilst they could still get the other 3 (or 4) analogue channels apart from BBC2 [which will have been switched off].

That said, due to co-channel problems not all transmitters went straight to their final frequencies (or powers) at the second switchover event. Some areas experienced additional switchover events, due to neighbouring transmitters reallocating their frequencies as they switched over. In fact some transmitters also experienced this before their switchover.


At every stage of the process all Freeview digiboxes and TVs needed retuning. Those who had to employ someone to come and retune their box had to worth consider whether they could do without some of the channels after the first retune event so they only had to pay for an engineer to call once, when the second retune is required.


Incidentally, on the subject of retuning, try not to be a cheeky git, phoning up a retailer for free retune advice if you didn`t actually buy the TV from him !  If he tells you to “sod off !” he`s quite within his rights…… Remember, you really should get your information from where you spend your money, and vice versa (as it applies to us).  Don`t unfairly exploit harassed TV shop staff (or us) !


Alternatively phone reception advice.


Remember, they`re paid to advise you, unlike the above mentioned chap (or us).


The golden rule is, if having problems with your digital TV, FIRST TRY RETUNING IT !

If possible delete all the existing tuning, then try a full retune.


Retuning help available here www.tvretune.co.uk and on telephone number 08546 05 11 22

Digital aerialand Postcode predictions

Digital picture quality  (worse, for some people)


Less robust digital signal


"Digital cliff edge"  including "error correction" (FEC)


Replacement aerial


Retune, retune, retune......


Unreliability (and unfixability) of digital sets


Obsolete digital equipment


Extra programmes ? It`s all repeats anyway !

Do I need a new aerial ?  including :

Digital Myths

Digital Negatives  including :

Subjects on this page are listed in the following order :

Digital Positives   including :

Basic Fault Finding & Retuning Tips

Freesat (Free To Air Digital Satellite)

Cable TV

High Definition TV (HDTV)  including : What exactly does HD Ready mean.......

Digital Switch Over (DSO)  including : How the switchover occurred

Digital Multiplexes (MUXES) including :

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Programme to MUX allocations


PSBs (Public Service Broadcasting)


MUX naming, and renaming......

Digital picture/sound quality (better, for most people)


More channels


PVRs (Personal Video Recorders) / Freeview +


Improved reception since digital switchover (DSO)


Nearly all aerials work for digital after DSO


Selling off some of the spectrum  (incl CH61/62 clearance)


High power 4G transmissions (filtering problems)


Extra channels after DSO ?  1 Interleaved Spectrum

2  Channel 31 to 37 "gap

We are more than willing to give advice to those actually purchasing from us. Could those only seeking information please just find the answer somewhere on this site, or ring an aerial installer local to them, or call the reception advice phone numbers.

Digital Positives


What I said about inferior digital picture quality is undoubtedly true, but that`s only if you had good analogue signals. Unfortunately, many people did not have good analogue signals because they either live in a "fringe" area or they have a poor quality aerial installation. If your signal is of sufficient quality to reliably drive a digital box there are a lot of people who have got a greatly improved picture,  digital is particularly effective at eliminating ghosting, provided the signal stays at the top of the "cliff edge", see graphic.

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The sound quality on digital TV is “near CD quality”. Better sound quality is always a positive but remember the analogue system had FM sound anyway, also see Nicam. If you were unhappy with the sound quality of your analogue TV it was more likely to be deficiencies in the sets amp and speakers than anything else. If your set had a SCART (or Phono audio out) putting the sound output through your stereo would have improved things, as, in fact, it still will with digital, though think of the neighbours if you`re tempted to turn it up !

If sound quality is important to you I would buy a Freeview box (or digital TV) with separate Phono audio out sockets (though you can also use a SCART to Phono lead) which gives you the option to connect the STB to your Hi Fi. This is particularly useful if you want to listen to the radio stations which are also available on Freeview.

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There are more programme channels available and the chances are you`ll like at least one of them. Most STB`s have basic "interactive" functions on "the red button" which could be really useful, for instance by giving you a choice of which sport at the Olympics you want to watch. Unfortunately at last Olympics the choices seemed to be Synchronised Team Pursuit Fencing or Rhythmic Freestyle Sandcastle Building rather than the swimming that I actually wanted. Consequently I was even more frustrated than I was before ! Let`s give it the benefit of the doubt though, it`s potentially a worthwhile feature.   

One can buy the relevant card for ones PC and watch TV on it.

In addition there are a number of radio channels available including R5 Live which is not transmitted on FM, see paragraph above.

Lastly you can buy a Personal Video Recorder (or PVR) which can pause and rewind live TV. From only about £100 you can buy one which will record up to 180 hrs of TV and has 2 tuners to record one channel whilst you watch the other, or record 2 different channels at the same time ! Who needs Sky+ (at great expense) when you can get Freeview+?  PVRs certainly make recording much easier, particularly when using "series link", but it`s not all good news. PVRs do have their down sides. Some are quite complicated to use, they can also be unreliable in recording programmes, occasionally they freeze up and must be hard reset (i.e. switched off then on at the mains....) and if they ever fail completely all the recordings are lost. Furthermore I think it appalling design that most PVRs (or Virgin + or BT Vision boxes* ) don`t have RF modulated outputs, which means you can`t pipe the output of the PVR round the house to watch on other TVs, like you can with Sky boxes (actually you can but you`ll need to buy and fit an RF modulator).

Cynics, like me, would say they only do that to force you to pay for another box.

To be fair, extra PVRs can easily be added to the system, unlike an extra Sky box, but some PVRs are £200, and anyway, if you`ve recorded a programme on a PVR in the lounge and you want to go and watch it in the bedroom, it`s not like a Video where you can just take the tape out.

It`s even worse with Virgin (cable) and BT (BT Vision) because it`s not as easy (or cheap) to source an extra box, and it`s not as easy to add it into any distribution system you may have.

In my professional opinion those companies` designs are so poor that customers should complain to them and get them to pay for any modulator you may require.

Read some more of the manufacturers` pathetic excuses on this Forum thread.


* Not the newer black ones (from late 2009) anyway.

The reliability of digital transmissions improved when they turned off the analogue signal at Digital Switch Over (DSO). They considerably upped the power outputs of the 80 transmitters already broadcasting digital, as an example Crystal Palace`s power went up from 20kW to 200kW. Just as significantly they also began transmitting 3 of the 6 MUXES (the most important ones, the so called “PSBs”) from all of the smaller repeaters. The latter are the “fill in” transmitters which are used to increase coverage in fringe areas. Note how they do not broadcast all of the Freeview output from all of these relays*. Better still, of all the hundreds of repeaters all but three [including Cefn Mawr in Wales] probably continued to work fine with existing aerials. Though this was/is less likely to apply for some cheap crappy Contract aerials though......


As we`d been telling everybody for years the great majority of transmitters reverted to their original groups and unsurprisingly this includes all of the “Big Five” which cover about 30 million of us.

In fact all  the original 80 Digital transmitters continued to broadcast the main three MUXES (the so called PSBs) within band, i.e. those who are quite satisfied with the “basic” five channels, almost certainly continued get them with the aerial they already had !

As for the other three MUXES, 21 of the 80* transmitters broadcast between one and three of the other 3 MUXES outside of their original group. Fortunately five of these transmit the new frequencies below the existing group, meaning that those in reasonable signal areas will still have a good chance of picking up the signal OK.

That leaves 16 out of 80 transmitters, but of these only eight are “main” transmitters, these being Belmont, Bilsdale, Craigkelly, Knockmore, Rumster Forest, Sandy, Sudbury and The Wrekin. It must be admitted that for these  an aerial change may well be required in order to receive all the digital transmissions, as opposed to just the PSBs, which will be available from your existing antenna in the nearly all cases.

So, for the great majority, when the DSO occurred most of those who hadn`t yet “upgraded” to a wideband  (and most people never needed to do so anyway) then picked up the digital signal OK. Furthermore many of those who live in fringe areas could then, if required, take advantage of the superior gain of grouped aerials to improve their signal.


Also see Major Transmitters : Which Aerial To Use.


* Only 80 of the biggest transmitters broadcast all 6 MUXES, they`re all listed here. Officially "only" 90% of people can get on a 6 MUX transmitter, but I`m sure it`s far higher than that.

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As mentioned above Ofcom have identified some ‘spare’ channels within the new (smaller) TV band which they believe will be available after DSO, possibly for TV transmission. There are two different (potential) plans here, but, as far as TV broadcasting is concerned, neither include CHs 61 to 68.   

(Information correct as at December 2011 : Ofcom)


The first is known as interleaved spectrum channels. These were originally slated for auction to the highest bidder but in 2011 the government announced that they could only be used for local TV stations. It remains to be seen how many will actually get off the ground but that`s the plan. The latest list of possible frequencies and radiation patterns for use by local TV channels is on this Ofcom PDF document (p14 to 17 of 115) and it will be noted that the virtually all of them would be receivable on the same aerial group as the post DSO transmissions. There are tentative plans for up to 49 local TV stations (p14 to 17 of 114 in the PDF). In the Ofcom document 21 of the stations are designated phase 1 and 28 are phase 2. The former are more likely to be transmitted than the latter.

For more up to date details of local TV stations see this web page.

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Even the higher post switchover digital power outputs are all significantly lower than the analogue ones were but the nature of the digital signal means the output levels do not have to be as high to give a noise free picture, i.e. no “grainyness”. Theoretically the Digital signal only needs a 26 dB signal to noise ratio to achieve a “perfect” picture, as opposed to the analogue which requires around 44dB. Thus the Digital signal received at the antenna can be 18dB lower and still give (what passes for) a perfect picture.

Thus, after switchover, when the powers were all increased significantly, all transmitters outputs are actually higher (relative to what they theoretically need to be) than they were when transmitting analogue. It must be remembered that the consequences of a digital drop out are more annoying to the viewer than for a flash of interference on an analogue picture.


Also see "lower is higher" and actual signal levels.

     

OK, so you may need to pay for a new aerial (most people won`t though) but you`ll need a new one sometime anyway. Nothing lasts for ever, though some things last longer than others !

If you have a steel pole it will eventually rust through (see poles), your down lead will eventually perish and/or wear through (by the action of the wind if it is not pinned to the slates, see cable) and sooner or later your aerial will fall apart, particularly if it is a "Contract" or a Bacofoil  X-Beam.


See article on finding a decent aerial installer (and tradesmen generally).

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“FreeSat” (Free To Air Digital Satellite)


Freesat is transmitted from the same satellite (Astra 2D 28.2°E) as Sky. This is important because it means that any dish which was installed for Sky should pick up Freesat !


Those who live in an area which can`t get Freeview (terrestrial digital through your aerial) have no choice but to go down the “Freesat” route, that is to say through a satellite dish.

The thing is, are you sure you can`t get Freeview ? We`ve had customers come in to us saying they can`t get it in their area, we look on our installs map (more accurate than the Post Code checker....) and we`ve done digital install jobs on their road, no problem !  That said, there are sites which will struggle, though an even higher percentage of people can get Freeview post switchover.


Freesat is a completely different system from Freeview

and the STBs are not interchangeable.


When I last looked Sky would supply and fit the system for about £150. This seems quite

reasonable against the cost of a decent quality aerial installation (though you obviously have to pay through the nose for the programmes.....). In fact if a more sophisticated antenna/amplifier is required then Freesat may actually appear to be cheaper. In May 2008 the BBC (and ITV) launched a free to view satellite. Unfortunately that is not the whole story and for the reasons listed below I would strongly advise anyone, who has any sort of option, to go for the Freeview system.

Obviously those who actually want the pay channels may need to go for Sky or Cable, though Top Up TV is available through your aerial.


1 Set top boxes (STBs) for Freeview are available from around £15 upwards and can be obtained virtually anywhere, even at the supermarket. Sky satellite boxes are about 3 or 4 times this price and are rather more difficult to obtain as well. Freesat boxes are quite a bit cheaper than Sky boxes, and easier to buy, but they still don`t sell them down my local Morrisons.


2 More or less all TVs/Videos/PVRs they have a Digital tuner “built in”. For these to work you need a Terrestrial Digital (i.e. Freeview) signal. Most of those on Freesat still require a separate STB for every set.


3 Many homes have TV aerial distribution systems fitted so as to get decent signals to all the  sets in the house. Assuming it is of reasonable quality (or you are just lucky ! ) the system should be compatible with Freeview. Since the signal is at UHF frequency it may even work with the kind of budget low specification cable that house builders (and some aerial installers......) put in as standard. Satellite distribution systems (i.e. signals from the dish to a number of  STBs, rather than from one STB to a number of TVs) are very much more complicated and expensive.

Because the satellite signals are at much higher frequency than the Freeview UHF signal it is unlikely that the type of low quality cabling mentioned above would suffice, so you may even require your house rewiring too. If the cable is run in the walls that is obviously rather problematic to put it mildly.


4 Heavy rain or snow (remember that ? ) can degrade the picture "rain fade", possibly giving no picture at all for particularly persistent powerful precipitation [I love alliteration]. I was reminded about this during a phone conversation with my brother in New Zealand, and he said they had no (Sky) TV because they were suffering from heavy snow !  The vast majority of people have the standard 43cm mini dish (standard fit from Sky), a larger Zone 2 dish would usually improve matters but many people wouldn`t want one on their property.


5 If you`re using the Sky free channels (as opposed to Freesat) in order to receive all the available free channels sometimes need a Sky card . At the moment this is quite cheap but it is only available from Sky and anyone who has had dealings with them can testify that it can be a frustrating business..... In fact when Which? researched call centres in Jan 11 they found Sky was the worst, and they`ve got some decent opposition in that department, particularly Royal Mail, and (ironically) BT, plus all the broadband providers, obviously.  That`s the modern trend, companies don`t actually want to talk to their customers, not unless it`s a voice activated computer. I never talk to them. Well actually I do, I swear at them till they put me through to a human being. You should try it, it`s very satisfying.  

Some of the of the programmes on Freeview are not available on Freesat. As far as I am aware Dave or the UK History channel are not available on Freesat although the situation could change so you are advised to check. Apparently UKTV History changed its name in March 09 to “Yesterday”, and it also changed its Freeview MUX allocation. Yet another example of name changing bollox.  Isn`t all this digital TV complicated enough......

On the other hand there are a few more channels on Freesat than on Freeview.

So you might get 120 odd channels of crap *, instead of the 80 odd channels of crap on Freeview.

Big deal.

So you can waste even more time going through the TV guide confirming there`s nothing actually worth watching anyway.  Life`s wonderful.


* Remember they aren`t all TV channels, some are radio channels.

Who listens to the radio through a bleedin` satellite anyway ? That`s what I want to know. Whatever next ? Gas companies selling electricity ? And I bet they`d charge too much for it.

The world`s gone mad.

Cable TV    


The third option for Digital TV is Cable, of which NTL Telewest was the main supplier though it`s now called “Virgin Media.   (Don`t you just hate all this name changing b****x ?)

As with Sky it is a completely different system and the STBs are not interchangeable for either Freeview or Sky.

Cable is similar to Sky in that it has far greater bandwidth (by utilising fibre optic cable) than Freeview. “Pay To View” is also available should you want it. Unfortunately it also has many of the disadvantages of Sky. A separate STB is required for each TV (and always will be) should you want to watch different Digital channels on different sets. All of these boxes are chargeable, a nice little earner (for them) methinks

For details of the implications of splitting a Cable signal  (i.e. to the STBs rather than from one STB) see relevant article in the Appendix. As for splitting the signal from a Cable box (to multiple TVs) one other disadvantage of nearly all cable boxes, is no modulated RF out, which means you can`t send the output of the Cable box around the house, like you can with a Sky box. My cynical side has an obvious explanation for why Virgin don`t allow you to easily do this....... In fact, my professional opinion, it`s absolutely crap design, and if it were me I`d get onto Virgin and ask them  to pay for the cost of an external RF modulator, which is what you`ll need to buy to do what you should be able to do without one.......

You`ll obviously have to find out for yourselves but I`ve heard some cringe inducing tales about how difficult it can sometimes be to get through to them on their customer service telephone line. In fact the Which? report of Jan 2011 says they`re nearly as bad as Sky, and that`s bad.......

I always think it`s worth checking any potential suppliers phone service before you commit yourself to them, and not just the sales line !  

There is one definite advantage over Satellite though, no bleedin` dish on your wall !

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The next step is to pull everything out (having made sure you draw a diagram of where all the cables go back in, obviously.....) and connect the lead direct from your aerial straight into your STB or digital TV. For the purposes of this diagnostic test it is very important that the signal from the aerial isn`t going through anything else (like a Sky box for instance) before being plugged into your TV. Does the fault disappear ?  If so find the cause by elimination. Is the fault co-channel from an RF modulator ?


Still faulty ?

Well at least you`ve eliminated a lot !

Incidentally, different models of STB (or indeed digital TV) have differing tuner sensitivities, and it`s not always the expensive ones which are the best either. We`ve had customers tell us they`ve got significantly more reliable digital pictures by simply changing the STB.


If after trying all the above you`re still in doubt as to if the fault is the signal or the box I`d swap round the digiboxes/TVs (or even consider buying a another STB) and trying that by substitution. It`d be cheaper than calling someone out to check your signal !


Use of a “hard reset” (technical name for pulling out the mains plug for a

minute or so....) is often successful at “rebooting” a locked up digital TV or STB,

and this is especially the case with PVRs/hard disc recorders.

Don`t forget to check your TV (or box) is tuned in correctly, and to the

most suitable transmitter. It may be necessary to tune your TV in manually

or at least do a “Full Scan”, as opposed to “Add Channels”. Be bold, do not be dissuaded if you get a message warning you will delete existing channels !


Some boxes allow you to delete all channels before you do a scan, and this can be particularly helpful if you`re suffering from transmitter overlap and you want to reorder the channels on your TV.

A few boxes/TVs, notably some Humax, require you to go into the channel list and manually delete all channels before then doing a rescan, otherwise they just add more channels on, leaving the incorrectly tuned ones also on the list !  If your TV/STB hasn`t got a delete channels function you could try factory reset (though this will delete all your planned recordings….), or you could try pulling out the aerial, then doing a “Full Scan” (to try and delete everything) then replace the aerial and repeat “Full Scan”.  


Particularly if you`re doing your first rescan and having problems it may even be the signal strength is too strong and your TV`s tuner is overloaded. In fact you may even need an attenuator, or if you have an amplifier, try removing it (but don`t just turn it off because then you won`t get any signal through it). Note, many TVs/Set Top Boxes indicate no signal (or low signal), even when the actual fault is excessive signal !   I had this very problem at the shop.


From Autumn 2013 beware of the new powerful 4G broadcasts. These are most likely to affect systems with amplifiers, RF modulated signals (like from a Sky box) and transmissions at the very top of the band, particularly channels 59 and 60.


Finally, some TVs and boxes (particularly PVRs) seem to take time to sort themselves out. I don`t know why. So if you`re only getting one set of channels (i.e. you`re not suffering from transmitter overlap) but the channel numbers are all to cock, try leaving the box for a day or two after your full retune. They sometimes sort themselves out !


Lastly, after you`ve exhausted all alternatives, you could try the extra hard reset.

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(incl possible Local TV CHs)

The graph on the right shows how the relative picture qualities of the analogue and digital systems vary as the signal quality deteriorates.


Note how with a perfect signal the analogue picture is superior to digital (not HD), then falls behind as the signal quality degrades, before retaking the lead when the digital signal runs out of error correction data and falls precipitously down the ”Digital Cliff Edge”.


Note that the quality of the [SD] digital picture can vary according to programme, some (mainly the crappy, “all repeats” esoteric ones.....) are more compressed than others.

Incidentally (analogue) FM radio and (digital) DAB radio follow the same kind of pattern as the above graphic.

When the Digital Switch Over (DSO) occurred those with Portable TVs running off “set top” aerials tended to be affected in the most negative way. The same situation applied (at some sites) to boaters and caravanners, particularly those using Omni aerials. You do need to be in a pretty strong signal area for a set top, and particularly an Omni, to give you a reliable signal.


* The amount of error correction data (known as FEC, or Forward Error Correction) was reduced on the COM MUXES during early mid 2012. This was so the broadcasters can squeeze more programmes onto each MUX.

This is, I`m sure you`ll all agree, absolutely fantastic !

We got even more crap and/or repeated programmes, and, they`re more likely to break up whilst we watch them.

Now I don`t know about you, but I love life.


Note, the FEC reduction only occurred on the COMs (MUXES 4 to 6), not  the PSBs (MUXES 1 to 3) and, if it causes a problem, it can usually be overcome by a better aerial install.


Most people had Teletext and that was a also digital system, so was Nicam stereo. Both of these demonstrated the same type of failure mode as digital TV, and also the importance of a decent signal / aerial system because it is deficiencies in reception which were the most likely cause of problems with either Teletext or Nicam.

Teletext is particularly relevant when it comes to error correction data. The header line had significantly more of the latter than had the main body of text. This explained why even when most of the page was a meaningless collection of random letters the header line could still make a reasonable amount of sense. And in the case of Nicam many TVs had the facility to switch it off (and revert to the original FM sound) if the signal level degrades to the point where drop outs are excessively annoying.

This is perhaps the ultimate proof of the more robust nature of the analogue signal .

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After switchover completed a gap from CH31 to CH37 opened up in the UHF transmission spectrum. In June 2013 Ofcom announced this gap would used for two new HD MUXES to be broadcast from the 30 transmitters with the largest population coverages. These transmissions starting late 2013/early 2014. Details of each transmitter`s MUX allocations are to be found on pages 34 to 36 of this Ofcom document, also see this link and this one. It will be noted that the transmission powers of the new HD MUXES are lower than for the existing 6. The CH31-37 gap is actually quite significant because because nearly all aerials will work there. All A group aerials will pick it up as will most B group aerials. Even many C/D group aerials (the decent ones anyway) will still work, after a fashion, in the channel 30s [see aerial group curves] though it must be admitted that most C/Ds wouldn`t be working at their best at CH31, particularly in a poor signal area. So, if you`re on a C/D group transmitter (e.g. Winter Hill)  and you want to "cover all bases", but sacrifice a bit of gain/directivity, I`d go for a Yagi18E (or a DY14WB) rather than a Yagi18C/D (Dec 2011).


Back in 2012 Ofcom started a discussion about selling off even more of the TV spectrum, i.e. that from CH49 up to CH60 : “the 700MHz clearance”, and in Nov 2014 they more or less confirmed this would happen. This is effectively the death of the C/D group… The new wideband will be the (existing) K group !  In October 2016 Ofcom confirmed that the 700MHz band would be available for mobile data by the second quarter of 2020.  Also see changing the groups, past, present and future ?


The newer low power HD transmissions may be relatively short term if “the powers that be” keep trying to nick more and more frequencies for mobile broadband and stuff !


I`ve often thought that the CH31 to 37 gap (where, let`s remember, all TV aerials will work, to a greater or lesser extent) could be more than a mere co-incidence. Could it be there`s a long term plan to transmit all MUXES throughout the UK on a Single Frequency Network (though there are problems with this) using just these channels, then sell off the rest of the spectrum ? ! ? But then I am an infamous cynic…… (Oct 2013)

Unfortunately many of these interleaved spectrum frequencies will not be transmitted omni directionally (or at full power) due to co-channel issues with adjacent transmitters, the radiation patterns are in the linked Ofcom publication (in alphabetical order from page 25 of 115 There is a possibility of up to 49 local TV stations, but the thing to bear in mind is the local stations are just that, local. Unlike the transmitters` other TV output in most cases the broadcasts are targeted at a particular area. Take the possible local channel for Reading, the radiation pattern from Hannington (p95 of 115 on the above linked Ofcom PDF) is narrowly focused to the north east, whereas all its other output is essentially omnidirectional.

(Link)

I do wonder how the government are going to end up with spare slots in the RF spectrum to sell off because one only has to look at the Transmitter Channel Allocations for the Sheffield area to see how well filled the RF spectrum is, but the "powers that be" think there will be so they reserved some channels to sell off. For the record, originally the “reserved” channels were 31 to 37, 39 & 40 and 63 to 68, but in 2009 the “800MHz clearance” was adopted. This basically means that CHs 61 and 62 will be cleared of Freeview transmissions but CHs 39 and 40 will be released for it. Thus the “reserved channels are now planned to be 31 to 35, 37, and 61 to 68. This has some unfortunate consequences in that all MUXES originally allocated to channels 39, 40, 61 & 62 will require reallocating with all the retuning that that will entail. Basically the MUXES which were on CHs61 and 62 will be moved to CHs 49 and 50, and those which were on CHs 49 and 50 will be moved down to CHs39 and 40. The reason for all this muxical chairs is to keep the MUXEs within the original groups of the aerials, though I have to say it`s probably somewhat unnecessary because I`ve never tested a (decent) C/D group aerial which isn`t still working pretty well down on CH39. There is one beneficial side effect of moving some of the MUXES down the band, because grouped aerials generally work OK below there designed for band, so more people may well be able to use grouped aerials post DSO than was originally planned. However, generally speaking, some crappy contract C/Ds might  not work as well in this regard.

There is a bit of a problem using CH61 and upwards for very high power 4G (sometimes called LTE = Long Term Evolution) mobile phone signals, and that is you can cause overload interference in any amps used in TV distribution systems, or even, in extreme cases, in the actual tuners of the TVs or STBs. It is important to note here that interference is most likely to occur in amplifiers (sometimes called “boosters”) and therefore that`s one more reason to try and use a splitter - rather than an amp - in the first place !  Now the standard way of curing this type of problem is to use a filter but you cannot make a filter which will sufficiently attenuate a large signal on CH61, yet let all, or even most of, the signal on CH60 though. Well you can to a certain extent, but it`d be horrendously expensive. To economically achieve the degree of filtering necessary to remove the proposed high power mobile signals would need a gap of between 2 and 4 channels (depending on the losses in the filter). The mobile phone companies are supposed to be paying for the filters but only one per house, so if you`re feeding more than one TV you`ll have to put it on the input to the splitter (or amp). But if it`s an external splitter how are people going to retrofit such filters ? Particularly if they can`t even get to it ! Somebody hasn`t really thought this through have they ? Even if you put a filter on the front end of a system there`s still the problem of all the houses wired up with cheap crappy cable, unscreened wall plates and budget fly leads ! ! !

It`s worth noting that an A group, B group or K group aerial (plus the Log36) can help filter out the 4G signals, but not, it must be admitted, as well as a decent inline filter. Also, if you fo suffer from 4G interference,

Anyway the auction for the 800MHz frequencies was held up to Feb 2013 and raised £2.3 billion. Now that might sound a lot but it was actually 1.2 billion less than expected, and let`s not forget that the 3G auction back in 2000 raised £22.5 billion....... So that might decrease still further the chance that FM will be switched off !  

Note EE actually started 4G in October 2012 but that wasn`t using ex TV spectrum it was using frequencies further up the frequency range (at around 2GHz). Transmissions of 4G within the TV UHF spectrum are due to start from summer 2013.


Helpline number for 800MHz / 4G / LTE  problems = 0333 31 31 800. Also see at800 (SPX….)


External link to article on 4G problems.

Map of TV transmitters planned to use CH59 or 60, which are those which might require the most efficient (i.e. expensive) filters, not that any CH 60 filter will work perfectly on CH61 !

Radiation pattern from Hannington transmitter for the proposed Reading local TV station Failure modes of digital v analogue TV illustrating the digital cliff edge Digital picture breakup, FRUSTRATING........

(incl additional HD CHs)

Digital TV MUX names, and renames, and renames......

And it got even more complicated as the planned local TV channels began transmissions….

So, we now have three levels of service :


8 MUXES from the 30 largest transmitters (coverage wise)


6 MUXES (the main ones) from the 50 next biggest transmitters


3 PSB MUXES from all the smaller repeaters.

Digital Multiplexes (MUXES) / PSBs


The Digital system (at a loss of some quality and signal reliability......) can broadcast up to 20 programmes per transmission channel. Each one of the latter is called a Multiplex or MUX for short. The channel numbers/broadcast frequencies of a number of the main transmitters can be found using the Nationwide Transmitters page, also see Digital UK`s regional transmitters, it`s set on Yorkshire but the others are available via the drop down menu.

The basic programmes found on each MUX are listed below. This information can be used as a diagnostic tool to identify the cause of reception problems. For example if blocking/freezing tends to occur on programmes of the same MUX (but the other MUXs are OK), then the problem is almost certainly a signal or “set up” fault rather than the box, see Digital Cliff Edge. On the other hand if all the MUXES are affected it`s far more likely to be a faulty box, or an incorrectly set up system. Also see digital multiple transmitter reception.


Do not discount the obvious !  I can remember when the ITV channels started breaking up on one of our PVRs (digital recorders) but the BBC channels were fine. At the time MUX1 as at much higher power than MUX2, so I put it down to that, until my wife started complaining, so I felt I had to try and sort it out, you know how it is........  I was amazed to find that the lead into the affected PVR had nearly fallen out. It was incredible it worked at all. Still, it was easy to repair the "fault", and the wife was impressed I`d fixed it, so what more can you say !

3  700 MHz clearance

K group to rule OK !