Hillsborough
Sheffield
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Digital TV
Note, as work takes place on various digital transmitters (to prepare for the DSO) you may
experience problems, e.g. with certain MUXES disappearing. First try rescanning your
TV / set top box (do it manually if possible), but if this fails to work check on transmitter work
or call the reception advice phone numbers. Also see basic digital fault finding.
Subjects on this page are listed in the following order
Do I need a new aerial ? including “Digital Aerial”
Digital Negatives including "Digital Cliff Edge", Teletext and Nicam
Digital Positives including consequences of the Digital Switch Over / DSO
improved digital at switchover
Freesat (Free To Air Digital Satellite)
Proposed Digital Switch Over (DSO) Dates including how the switchover will occur
Digital Multiplexes (MUXES) / PSBs including MUX names/renames
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 get all five programme channels perfectly then you will almost certainly get Digital OK.
This simple test proves 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. If you are in the Sheffield area and only get a poor C5
the chances are you will require your antenna changing. You may, or may not, experience
intermittent blocking/freezing depending on the signal strength in your location and the quality of
your aerial installation.
One thing which needs to be stressed is the unreliability of the "Post Code Prediction 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-
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-
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 punchline 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, a better quality amplifier/splitter, or nothing at all ! And, arguably, most people fall into the latter category.
Note that after Digital Switchover (DSO) many aerials which are not “digital” now
will be able to pick up the Freeview signal.
There are so many misconceptions and so much (deliberate ?) misinformation about "Digital"
that we thought we should tell the unvarnished truth. We can do that because unlike the
government (wanting to use the RF spectrum to make money, not that we should object to that ! )
or the TV retailers (wanting to sell you a new TV...) we have no hidden agenda. 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 £25) 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. Furthermore, for ease of repair, we actually recommend that you continue to buy an
analogue TV and use it with a Set Top Box. The fact is that many unscrupulous people are trying
to make money out of the Digital Switchover as the BBC have found, also see www.paras.org.uk.
I thought we would list the Positives and the Negatives of Digital.
So we can end on an upbeat note we`ll start with the Negatives.
2 Some people will need their aerial and/or downlead changing.
This can mean swapping to a wideband antenna but for most people it does not, they will
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. Occasionally it can be helpful to use a
second aerial on a different transmitter to achieve the best of both worlds.
Unfortunately some people will have no alternative but to go down the "Freesat/Sky" route,
Boo Hiss. Yes, you aren`t the only one who hates Sky ! Or there`s Cable TV but that has
its own drawbacks as well.
Incidentally, I would always advise anyone with Sky to have a back up aerial. Not only will
it mean you can tape one programme whilst watching another but if your LNB/Dish/STB
fails you will still get the basic analogue 5 channels plus (for most people) Freeview.
We regularly get customers phoning us up in desperation at Christmas, their Sky has
stopped working and no-
3 The Digital signal is not as robust as the analogue one. An analogue signal can be really
quite poor and one will still get a watchable picture. It may be grainy, and maybe even
ghosting as well, but when Mr Rooney sends a right foot pile driver towards the top left
corner of the Brazilian goal in the 2010 World Cup final, you will 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-
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 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.
When (if....) the Digital Switch Over (DSO) occurs those with Portable TVs running off
“set top” aerials are likely to be affected in the most negative way. Many people use
portables in upstairs rooms (with no connection to their outside antenna) and put up with
a less than perfect -
reasonably strong signal, they may not get much worth watching after the DSO. That said,
the digital transmission power is going to be significantly increased, so who knows ?
You may well find that the BBC channels are slightly more robust because they use a
different method of transmission, 16 QAM rather than 64 QAM. This is at the cost of fewer
channels per MUX but I think it was a wise decision to use it. Having said that, the most
likely cause of superior BBC channels is because they are often broadcast within the
original transmission group of the transmitter and your aerial may require changing to
improve the reception of the other channels, see Digital Transmitters Nationwide.
Most people already have Teletext and this is a digital system, so is Nicam stereo.
Both of these demonstrate the above mentioned modes of failure and also the importance
of a decent signal / aerial system because it is deficiencies in reception which are 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 has
significantly more of the latter than has the main body of text. This explains why even when
most of the page is a meaningless collection of random letters the header line can still
make a reasonable amount of sense.
In the case of Nicam many TVs have 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 !
4 Every conventional (i.e. analogue) TV or video will need its own Freeview "Set Top Box"
(STB) if it is to continue working when (if...) they turn off the analogue signals. It is quite
common to come across people who find the operation of the Freeview box somewhat
complicated, in fact a significant part of our business is "setting up" customers systems.
This setting up also applies to many Integrated TVs.
5 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...... We can economically repair around 80% of conventional TV`s
(i.e analogue, non LCD, non Plasma, non Rear Projection) but with integrated sets it`s
rather lower than that, see Repairs. That`s why we advise people to buy an analogue
TV and a separate set top box. Doing it that way is more flexible as well.
Furthermore, until they turn off the signals at DSO, the analogue channels can be a
valuable diagnostic tool for tracing signal faults or indeed when “peaking up” your aerial at
installation. Signal fault finding on analogue is much easier than with digital signals.
* 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, which
most do) so don`t be forced to buy a new TV when you don`t have to. One last thing, there
have been rumours that the Digital system may be changed at some time in the future from
from MPEG 2 to MPEG 4. If were to occur than all the integrated sets could then become
obsolete or at the very least require a STB feeding them through the SCART socket.
So that`s yet another reason to go with a separate STB in the first place.
Some of the oldest digiboxes and digi TVs will gradually cease to function from Summer 2008 when the broadcasters "Split NIT" network changes occured. Note this will only become apparent when the digi box is retuned, as they occasionally have to be, like on the 30 of Sept 2009 when C5 moved from one MUX to another.
There are also a number of models of digibox/IDTV which will stop working at switchover because the transmission mode will change, from 2K to 8K. Just to clarify that, the 2K/8K problem will only become an issue when your transmitter actually switches over, e.g. Crystal Palace won`t be until 2012, (source Ofcom 30 Sept 2009).
There`s one last advantage to an analogue TV with a separate STB (or at least a digital TV
which also has an analogue input) in that many people add the signal from there Sky box
to their distribution system and the same with the signals from their CCTV cameras.
They`re both analogue signals modulated onto UHF frequencies. What`s going to them with
a digital only TV ? They won`t work ! It must be admitted that the vast majority of digital
TVs sold up to press are still analogue compatible, but still, it`s something to remember.
Incidentally, different models if 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 you do have any trouble with your Freeview signals the first thing to try is a “rescan” of
your set top box and if necessary do a manual scan. Next try pulling out the mains plug,
wait 5 or 10 minutes then put it in again. If it`s still playing up (and it isn`t a signal fault)
then throw it in the bin..... (also see What is an “old” TV ?)
6 Let`s be honest, most of the additional programme channels on Freeview (or Freesat)
are either repeats or they`re rubbish. I know that`s a subjective opinion but I suspect most
people would agree with it. 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, oh well.......
Then there`s gravitas, whatever happened to that........
Whisper it quietly but there 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 with only five channels.
Let`s face it she should be giving me more attention.
And doing more housework, obviously.
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......
1 What I said about inferior Digital picture quality is undoubtedly true, but that`s only if
you have good analogue signals. Unfortunately, many people do 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 will get a greatly improved picture. Digital can be particularly effective at
eliminating ghosting, provided the signal stay`s at the top of the "cliff edge", see graphic.
2 The sound quality is “near CD quality”. Better sound quality is always a positive but
remember the analogue system has FM sound anyway, also see Nicam. If you are
unhappy with the sound quality of your analogue TV it`s more likely to be deficiencies in
the sets amp and speakers than anything else. If your set has a SCART (or Phono audio
out) try putting the sound output through your stereo, 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 with separate Phono audio
out sockets 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.
3 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 which could be really useful, for instance by
giving you a choice of which sport at the Olympics you want to watch. Unfortunately at the Athens
2004 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 Freeview Plus recorder which can pause and rewind live TV. For 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) ?
4 The reliability of the Digital signal will improve when (if....) they turn off the analogue
signal at Digital Switch Over (DSO). The plans are to considerably up the power outputs of
the main transmitters and transmit 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 there are no plans to broadcast all
of the Freeview output from all of these relays. When the DSO occurs it is proposed that
(wherever possible) these transmitters will stay in their original groups. The planned
switchover for the Borders area reflects this strategy. Of the 61 transmitters in the Borders
region only 6 will be broadcasting Digital outside of their original groups and in all six cases
the new frequencies are below the existing group. This is significant because Yagi aerials
are reasonably responsive below their designed for band, so even those 6 locations will
probably still pick up the digital signal OK !
The frequencies for the repeaters for the Anglia, Borders, Central, Granada, London
Meridian, Scotland (Central), Scotland (North), Wales, West Region, West Country and Yorkshire have been released by Ofcom (up to Jun 2010). Of all the hundreds of repeaters listed there all but one [Cefn Mawr in Wales] will probably work fine off existing aerials. Though this is less likely to apply for some cheap crappy Contract aerials though......
There is a full list of “post DSO” channels for all the repeaters but it does contain some
inaccurate/incomplete MUX allocations, I`d recommend getting info straight from Ofcom.
On the 5 July 07 Ofcom released the planned “post DSO” channel
allocations for the 81 transmitters currently broadcasting digital
and full details can be found by clicking on this link.
As we`ve been saying for years * the great majority of transmitters are reverting to their
original groups and unsurprisingly this includes all of the “Big Five” which cover about 30
million of us. In fact all the existing Digital transmitters will broadcast the main three
MUXES (the so called PSBs) within band, i.e. those of us who are quite satisfied with the
“basic” five channels, will almost certainly get them with the aerial we already have !
As for the other three MUXES, 24 of the 81 transmitters will be broadcasting between one
and three of the other 3 MUXES out of their original group. Fortunately seven of these
will be transmitting 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 17 out of 81 transmitters, and of these only six are “main” transmitters, these being Belmont, Bilsdale, Craigkelly, Sandy, Sudbury and The Wrekin. It must be
admitted that for these “Dirty (half) Dozen” 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 vast majority of cases.
For the great majority, when the DSO occurs many of those who haven`t yet “upgraded” to
a wideband should then pick up the Digital signal OK. Furthermore many of those who live
in fringe areas can, if required, then take advantage of the superior gain of grouped aerials
to improve their signal.
* There aren`t many others who have been telling people about this because there are so
many vested interests who would rather the Great British Public didn`t know this little
snippet of information, i.e. that the vast majority of locations will get all the Digital
channels without an “upgrade” if they just wait till DSO.
Think about it. The aerial installers don`t want to publicise it because they`ll lose work.
The aerial manufacturers and retailers don`t want to publicise it because they`ll lose sales.
Even the BBC don`t want to publicise it because it`s part of their remit to increase the
uptake of Digital now, not at (or after) DSO. It`ll be interesting to see how many others
come clean about this vital piece of information now that it`s confirmed. Unless I`ve missed something the “Digital Television Group” didn`t even put this highly significant piece of information on their “Latest News”, just remember, we`ve always been up front about it !
Also see Digital Transmitters Nationwide and Major Transmitters: Which Aerial To Use.
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.
For the record the “reserved” channels were 31 to 35, 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.
See these two Ofcom documents, 600Mhz band and CH21 to CH60.
Anyway, the long and short of it is there`ll be a load of swapping about of the MUX allocations to accommodate this change in the reserved band but hopefully, when they`re flogged off, these are going to raise a decent amount and save us all some tax dollars..... One possibility is that CH63 to 68 will form the basis for the “Fourth Generation” high speed mobile broadband network (The Times 28 Nov 2008).
Ofcom have also identified some ‘spare’ channels which they believe will be available after
DSO and these are known as “interleaved spectrum” channels. There is quite a bit of
misinformation, about these so I got the relevant information direct from Ofcom (29 Oct 08).
The interleaved spectrum are frequencies which will probably be made available for
broadcasters to bid for and there are generally one or two per transmitter, though there is
no guarantee that they will be purchased for TV broadcasting. The full list is on P49
(or P46 ? ! ) of this Ofcom document. It will be noted that the virtually all of them are within
same groups as the previously announced post DSO transmissions. However many of
these interleaved spectrum frequencies will not be transmitted omni directionally or at full
power, due to co-
CH42 off Crystal Palace, which is one of the few of these channels which is not in the
same group as the previously announced post DSO channels. Also see Emley Moor.
For more details including the proposed radiation patterns of the main interleaved spectrum
channels see the relevant Ofcom page.
It must be remembered that all these radiation patterns may be subject to change due to
the “800MHz clearance”, and if the frequencies change so do the co-
At the moment the Digital power outputs are all significantly lower than the analogue ones
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
26dB 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. As an example, Emley`s 10kW Digital
output coverage is approximately equivalent (radiation patterns differ between the two) to
its 870kW on analogue. I`m not convinced that the power outputs are actually equivalent
but in any event they are due to be greatly increased when (if...) the analogue switch off
occurs. To continue the Emley Moor example its present Digital power of 10kW will be
increased to 174kW. That`s a big increase, even if one does bear in mind the inverse
square law, which means that to get double the coverage you need four times the power,
or something like that ! Some frequencies from some of the transmitters will only go up
to full power towards the end of the DSO in order to prevent interference to areas which
haven`t yet switched over. As an example, MUXES 4 to 6 off Caldbeck were originally
1.6kW before DSO, they will be 15kW during DSO, but will become 50kW after DSO.
There is a distinct possibility that many people, particularly those with with aerial amps,
may experience cross modulation interference or other deleterious effects when the power
is turned up, see variable gain amplifiers.
5 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 poorly constructed X-
See article on finding a decent aerial installer (and tradesmen generally).
For dates of the individual transmitters see Digital Nationwide
Note these dates, if you are going to have any work done on your aerial system I wouldn`t wait
until the last minute because at that point in time the laws of supply and demand will not be
working in your favour ! That said, read section 4, including increased power.
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.
Note how the planners have cleverly arranged the last date to coincide with the London Olympics.
I`m sure it`ll be OK, well probably.......
The switch will always occur mid week (usually on a Wednesday) in order to give people time to sort out any aerial work they need before the weekend.
In almost every case it will occur with analogue BBC2 being switched off first and at the same time the (low power) pre DSO MUX 1 [the main BBC channels] being switched off as well. MUX1 will then be reallocated to its post DSO frequency (often that vacated by analogue BBC2) and at its new, much higher, power. Two to four weeks later the rest of the analogue channels will be switched off and the other MUXES reallocated to their new frequencies at their (higher) post DSO power. There is no technical reason for this phased switchover, in fact it`d be easier for the broadcast authorities to do it all at the same time. It`s 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 can still get the other 3 (or 4) analogue channels apart from BBC2 [which will have been switched off].
That said, due to co-
At every stage of the process all Freeview digiboxes and TVs will need retuning.
If you have to employ someone to come and retune your box it`s worth considering whether you can do without some of the channels after the first retune event and just pay for an engineer to call when the second retune is required.
Incidentally, try not to be a cheeky git, phoning up a retailer for free advice if you didn`t
actually buy the TV from him. If he tells you to “sod off” he`s quite within his rights.
We sometimes get these kind of people phoning us, only ask advice from the supplier
where you spend your money ! It`s only fair ! Alternatively phone BBC/ITV 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 !
Retuning help available here www.tvretune.co.uk and on telephone number 08546 05 11 22
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 but also see Digital
Nationwide. The information for all the transmitters used around Sheffield can be found on
Transmitter Channel Allocations.
The basic programmes found on each are listed below. This information can be used as a
diagnostic tool to identify where faults may be on the system. 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 and 16 QAM. On the other hand if all the MUXES are affected (and, in
the Sheffield area *, all 5 of your analogue channels are OK) it`s far more likely to be a
faulty box, or an incorrectly set up system. Also see digital multiple transmitter reception.
* For other areas use the Digital Nationwide list to check if the digital MUXES in your area
are spread across same section of the band as the analogue. The same basic rules apply
though, even if just one of the MUXES is received perfectly but the others are not, it is
most likely to be a signal or “set up” fault.
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 digital STB. Does the fault disappear ? If so find the cause
by elimination. 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
seriously consider just buying a cheap STB and trying that by substitution. It`d be cheaper
than calling someone out to check your signal !
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 !
You could also try pulling out the aerial, then doing a “Full Scan” (to delete everything) then replace the aerial and repeat “Full Scan”.
“FreeSat” (Free To Air Digital Satellite) (Also see Cable TV)
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 most should be OK after the DSO.
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 and a Freeview box.
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 £20 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. Remember, until every TV
has digital as standard (see 2), you will need an STB for every set (or video) in the house.
2 Although we don`t recommend their purchase (see unreliability of Digital tuners) sooner
or later all TVs/Videos etc will probably be integrated. That is to say they will have a Digital tuner
“built in”. For these to work you will need a Terrestrial Digital (i.e. Freeview) signal. Those on
Freesat will still require a separate (and expensive) 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.
At the very least you will need a Quattro LNB (with it`s associated wiring) and possibly even a
multiswitch system, which should use a 60cm (or even 80cm) dish by the way.
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, possibly giving no picture
at all for powerful persistent 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 ! I accept that the same can happen for Freeview in marginal
areas but you can often do something about that by using a higher gain aerial. The vast majority
of people will just use the standard 43cm mini dish supplied by Sky, and wouldn`t usually want a
60cm or 80cm dish on their property, even if one of these were an option.
5 In order to receive all the available free channels you will need a card from Sky. 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..... The customer service of the BBC / ITV (for their
system) may be less frustrating, you`d have to phone them to find out !
There are more channels on Freesat, but they`re all crap anyway. Though to be fair so are most
of the programmes on Freeview...... Some of the of the programmes on Freeview are not
available on Freesat. As far as I am aware the UK History channel is 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......
Basically Sky are in it for the money (they want you to become a subscriber) and so tend
to go for a lot of “Shopping channels” and so forth.
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) and “Pay
To View” is 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, though as I understand it NTL do pipe the five basic
channels through the system, so on the second set (or the video) you have the choice of those
plus whatever is selected on the STB. As far as I`m aware the STBs themselves can only be
rented (not purchased outright) so if you want additional boxes that`s £15 a month each thank
you very much. Installation of the latter is free, though surely that`s the least you could expect for
£180 a year ! It is not really possible to split the incoming signal (i.e. to the STBs rather than
from one STB) yourself and install your own distribution system. That said, since you cannot buy
the boxes outright (not legitimately anyway....) this is not really that relevant.
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.
Having said that they`re supposed to have improved recently.
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 !
HD on Freeview (recommended by Ofcom in Apr 08) will consist of one MUX being given over entirely to HDTV, and the programmes which were originally on it then squeezed onto the other
5 MUXES. Note how this would not require any more wideband aerials to be installed than are currently required, or not as the case my be.... However, even using an entire MUX for HDTV will only give three (four by 2010 ?) HDTV channels and this would be at the cost of increased compression (i.e. a worse picture) to all channels moved onto the other MUXES.
Oh yes, and you`ll need a new box as well. No Freeview box/TV on the market (as at Sept 2009) will decode the new HD signals, though they are due to the market in 2010.
This raises interesting questions as to whether the TV sold to you as "HD ready", has been
mis-
Personally I think they`d have been better advised using the additional bandwidth to increase the error correction content of the signal (see Digital Cliff Edge) and thus make it more robust and less likely to freeze and pixellate. I suspect there are millions of people in marginal signal areas who would agree with me.
Whatever happens there won`t be a huge number of HDTV channels on Freeview, or any other
system, because there simply isn`t the bandwidth for it. You may get a few, but probably not that
many, and definitely not all of them. The plan is to begin broadcasting the three HDTV
MUXES as DSO occurs in each area (starting with Granada -
But, to be fair, what comes first, the chicken or the egg ? ! ?
From early/mid 2010 as the transmitters switchover they`ll start transmitting HD
on MUX3 (e.g. Mendip in Mar/Apr 2010), with those that had already switched (e.g.
Stockland Hill) being phased in, probably before the end of 2010. There are plans
underway for some of the larger transmitters (Emley Moor, Pontop Pike, Lichfield
[ = Sutton Coldfield], Crystal Palace & Black Hill) to start low power HDTV transmissions
in 2010 in advance of their full digital switchover. Crystal Palace is planned to
start earlier than the others (in Dec 2009) with the expectation that 50% of households
will have access to Freeview HD by the World Cup, subject to having the correct set
top box of course ! These initial transmissions will be subject to restrictions in
certain directions due to co-
The government want to sell off the spare slots in the spectrum (which could have been used for
more HDTV at DSO) and, to be honest, if it`s going to save me paying some tax they can go
ahead as far as I`m concerned.
You can get HDTV through Sky though unsurprisingly the grasping Murdochs will require you to
pay extra (when I last checked it was about £10 per month, that`s £120 per year, every year....)
and a special STB is required, at extra cost naturally, that`s £180 (or more). For all that outlay only
about ten HDTV programmes are available on Sky when I did this research, but check for the
current situation.
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.
NTL/Virgin Cable TV now do HDTV, but when I last checked there were only 2 (that`s TWO) HDTV
channels available. Oh yes, and you will require different STB, at extra cost naturally, haven`t I
just said that.......? The box is the equivalent of Sky plus (pause live TV, record a different channel
etc) but there`s a £75 installation fee, then £25 per month, every month, that`s £300 per year...... (Check for the latest position on cable 0845 045 0001)
High Definition TV is all 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 ?
Having said all of the above if HDTV gives a higher refresh rate to the picture (i.e. to get you what
you had before with the "obsolete technology" of analogue.....) then this would be worth having.
What I mean by refresh rate is the frequency the picture responds to new images, i.e. movement.
This is the weakness in the present generation of flat screen TVs (and the present digital system)
so 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 conventional CRT TV (with
a decent analogue signal) and a "normal" LCD or Plasma. 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 !
Having said all the above, and liberally taken the piss (you wouldn`t expect anything less, surely),
when the switchover comes the superior analogue picture (superior to “standard” digital that is)
will no longer be available. So, if and when my trusty 1988 B&O 21” TV (it`s really only a
Ferguson/Thomson in disguise...) finally expires I may well get an HDTV.
That`s mainly because I`m a TV engineer (an ex TV engineer ?) and I`d constantly be looking for
all the imperfections in the standard digital picture......
But I won`t pay any extra for HD, no way ! Why ? Because by then the three (later four) promised Freeview HD channels will have started broadcasting !
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.
1 A (standard definition) Digital TV picture is NOT superior to a good analogue picture. 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 can take advantage of its greater bandwidth to give more detail and a "higher refresh rate" to the picture. I accept that one has 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 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, then falls
behind as the signal quality degrades,
before retaking the lead when the
digital signal runs out of error
correction data and falls down
the ”Digital Cliff Edge”.
Incidentally (analogue) FM radio and
(digital) DAB radio follow the same
kind of pattern.
Now I know I`m a cynic, and I do expect the analogue switch off to occur *, but I also know you
can`t ever say anything for sure. I also know that if the switch off becomes a hot political issue,
and any of the parties think it will help get them into power...., they will change their mind on it
faster than you can say Jack Robinson....., or even just Jack......
* This is even more likely to take place if one takes into account that most wideband transmitters
are due to return to their original groups. Even those that don`t, will transmit the main three PSBs
within their original groups. The importance of this cannot be over estimated because it means
that most of those with no enthusiasm for digital (and I include myself in that ! ) will be able to get
the most important Freeview channels without paying for a new aerial or even a new TV come to
that. Hopefully all they will need is an STB at £25 or so.
The above may not apply to portable TVs running off “set top” aerials though !
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
Pre DSO : Programme to MUX allocations (For England, updated 30 Sept 09)
MUX 1 = BBC1 & BBC2 + BBC3 + CBBC + BBC News
MUX 2 = ITV1 + ITV2 / ITV4 + C4 + C5 / More4 / 4plus1 / E4 (Note Film 4 is on MUX 6)
MUX 3 / A = ITV3 + Top Up TV 1, 2 & 3 + QVC + GOLD + CNN + Virgin1 + Fiver / Five USA
MUX 4 / B = BBC4 + BBC Parl + CBeebies (+ BBC Radio 1, 2, 3, 4, 5 & World S+ BBC Asian N)
MUX 5 / C = Dave + Sky News / Sports News + Sky 3 + E4plus1(+ Talk Sport Radio etc )
MUX 6 / D = Yesterday + Film 4 + The Hits + Top Up TV 4 + Ideal World
For a comprehensive up to date list go to www.dtg.org.uk/retailer/dtt_channels
(England is the 1st column, Wales the 2nd, Scotland the 3rd & N Ireland the 4th)
Note that there was a reallocation of MUXES on Sept 30th 2009, the most significant being that C5 was be moved to MUX2. All digiboxes need to be retuned at every event.
Post DSO : Latest guess of programme to MUX allocations
MUX 1 / BBC A = Main BBC channels
MUX 2 / D3 & 4 = Main ITV, C4 and C5 channels
MUX 3 / BBC B = Three (four by 2010 ?) HDTV channels (initially BBC1, ITV & C4 ?)
MUX 4 / SDN = Top Up TV + QVC + UK Gold + Ideal World + E4 + FIVER + FIVE USA
MUX 5 / Arqiva A = Sky 3 + Dave + Sky News + E4 plus 1 + Price Drop TV
MUX 6 / Arqiva B = Yesterday + Film 4 + ITV4 + Ideal World + 4Music
For a comprehensive list go to www.dtg.org.uk/industry/dtt_channels.html#post
Note. 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. Post DSO these will be the only ones broadcast by
the smaller repeater transmitters. However It should be bourne in mind the these three
PSBs will contain the “main” channels, most of the rest are either repeats, or rubbish.....