Full Freeview on the Crystal Palace (Greater London, England) transmitter
 | Google Streetview |  | Google map |  | Bing map |  | Google Earth |  | 51.424,-0.076 or 51°25'26"N 0°4'32"W |  | SE19 1UE |
The symbol shows the location of the Crystal Palace (Greater London, England) transmitter which serves 4,490,000 homes. The bright green areas shown where the signal from this transmitter is strong, dark green areas are poorer signals. Those parts shown in yellow may have interference on the same frequency from other masts.
Are there any planned engineering works or unexpected transmitter faults on the Crystal Palace (Greater London, England) mast?
Crystal Palace transmitter - Crystal Palace transmitter: Possible effect on TV reception week commencing 25/11/2024 Pixelation or flickering on some or all channels 
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Digital television services are broadcast on a multiplexes (or Mux) where many stations occupy a single broadcast frequency, as shown below.
64QAM 8K 3/4 27.1Mb/s DVB-T MPEG2
DTG-12 QSPK 8K 3/4 8.0Mb/s DVB-T MPEG2
H/V: aerial position (horizontal or vertical)
Which Freeview channels does the Crystal Palace transmitter broadcast?
If you have any kind of Freeview fault, follow this Freeview reset procedure first.Digital television services are broadcast on a multiplexes (or Mux) where many stations occupy a single broadcast frequency, as shown below.
64QAM 8K 3/4 27.1Mb/s DVB-T MPEG2
DTG-12 QSPK 8K 3/4 8.0Mb/s DVB-T MPEG2
H/V: aerial position (horizontal or vertical)
Which BBC and ITV regional news can I watch from the Crystal Palace transmitter?
BBC London 4.9m homes 18.4%
from London W1A 1AA, 12km north-northwest (335°)
to BBC London region - 55 masts.
ITV London News 4.9m homes 18.4%
from London WC1X 8XZ, 11km north-northwest (345°)
to ITV London region - 55 masts.
Are there any self-help relays?
| Charlton Athletic | Transposer | Redeveloped north stand Charlton Athletic Football Club | 130 homes |
| Deptford | Transposer | south-east London | 100 homes |
| Greenford | Transposer | 12 km N Heathrow Airport | 203 homes |
| Hendon | Transposer | Graham Park estate | 50 homes |
| White City | Transposer | 9 km W central London | 80 homes |
How will the Crystal Palace (Greater London, England) transmission frequencies change over time?
| 1950s-80s | 1984-97 | 1997-98 | 1998-2012 | 2012-13 | 21 Mar 2018 | ||||
| VHF | A K T | A K T | A K T | A K T | W T | ||||
| C1 | BBCtvwaves | ||||||||
| C22 | ArqA | ArqA | |||||||
| C23 | ITVwaves | ITVwaves | ITVwaves | BBCA | BBCA | ||||
| C25 | SDN | SDN | |||||||
| C26 | BBC1waves | BBC1waves | BBC1waves | D3+4 | D3+4 | ||||
| C28 | -ArqB | ArqB | |||||||
| C29 | LW | ||||||||
| C30 | C4waves | C4waves | C4waves | -BBCB | BBCB | ||||
| C33 | BBC2waves | BBC2waves | BBC2waves | com7 | |||||
| C35 | com8 | ||||||||
| C55tv_off | com7tv_off | ||||||||
| C56tv_off | COM8tv_off |
tv_off Being removed from Freeview (for 5G use) after November 2020 / June 2022 - more
Table shows multiplexes names see this article;
green background for transmission frequencies
Notes: + and - denote 166kHz offset; aerial group are shown as A B C/D E K W T
waves denotes analogue; digital switchover was 4 Apr 12 and 18 Apr 12.
How do the old analogue and currrent digital signal levels compare?
| Analogue 1-4 | 1000kW | |
| SDN, ARQA, ARQB, BBCA, D3+4, BBCB | (-7dB) 200kW | |
| com7 | (-13.7dB) 43.1kW | |
| com8 | (-14dB) 39.8kW | |
| Mux 1*, Mux 2*, Mux A*, Mux B*, Mux C*, Mux D*, LW | (-17dB) 20kW |
Local transmitter maps
Crystal Palace Freeview Crystal Palace DAB Crystal Palace AM/FM Crystal Palace TV region BBC London LondonWhich companies have run the Channel 3 services in the Crystal Palace transmitter area
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Tuesday, 21 August 2012
P
Peter Suthers10:22 AM
Several times since Chrystal Palace Digital Switch Over, messages appear informing that new TV Channels are available & suggest a re-scan.
Does anyone know where one can find information regarding what the changes are each time?
Due to the height of my block I have to manually tune all 5 of my receivers (TV, DVD, PC & 2 x PVR) to prevent reception from other transmitters.
This is only worth it if the changes are relevant to me. I'm not interested in data & chat channels (& most of the TV channels to be honest, the guy who sang "57 channels & nothing on" was a prophet for our times).
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M
Michael11:42 AM
London
Michael: Peter - I am probably wrong but I have a suspicion that the "new services" detected may be the same old services coming from a different transmitter.
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Thursday, 30 August 2012
M
Michael2:48 PM
London
Michael: Finally tried our digibox next door. Same result as at my father's house - reduced signal strength, steady 98% quality, fine picture.
So we have:
- digital TVs that work fine on our signal;
- a digibox and a HD recorder which do not work on our signal, producing a lot of pixellation and breakup, but the digibox does work next door and (in a dip) at my father's house. I haven't moved the HD recorder but I am assuming it would also work elsewhere;
- one older digital TV (not mentioned before) which is a bit iffy;
- results similar whichever TV points I use, and whatever configurations of equipment and cabling I use.
- it was worse in mornings and evenings, but more recently yhe problem seems to there all day.
- an aerial engineer confirmed some weeks a go that the signal as received at the TV point was OK, but (a) I'm not sure he looked at quality as wella s strength and (b) it was behaving when they called.
So it appears that the digibox, HD recorder and (to some extent) older digital TV cannot cope with the low (and highly variable) signal quality, but the newer digital TVs can.
There are four TV points in the house, fed from a rooftop aerial with a distribution amplifier/splitter in the loft. As far as I know there is no masthead amplifier (not sure how I can tell, though).
If I switch off the amplifier, the signal goes, as I would expect. So to test if it is the problem I would have to mess around up in the loft playing around with what I have found in the past to be rather awkward connections.
With this setup, is it possible that I could have too much signal strength, and that quality problems not apparent next door are being amplified into something which is upsetting half my equipment?
Is there anything else I can try?
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Friday, 31 August 2012
J
jb3812:39 AM
Michael: I was having a look back through your various earlier postings for purposes of checking the history of your problems, but though whilst doing so came across a statement that appeared somewhat contradictory and which I couldn't quite fathom out, and so I would be obliged if you could clarify the following as far as the devices you are using to receive Freeview is concerned.
The statements referred to being:
>> Our main TV is analogue so has to be fed by either out Toshiba RDXV59DTJB2 HDD recorder or our (very) old Sagem Freeview box. <<
>> Is it plausible that the recorder and Freeview boxes are unable to cope with quality variations that are no problem to the TV? <<
What TV is being referred to in the latter statement?
However no matter what is being referred to it should be appreciated that no two Freeview devices have the same sensitivity tuners unless they are identical models to each other, this being the cause of the differences in performance that you have noticed, Panasonic TV's and Humax boxes being devices fitted with two of the best tuners around, and capable of giving reasonably glitch free reception in circumstances where other devices would be glitching every 30 secs or so.
The other point to remember being, that if when observing a signal its strength and quality is seen to be continually fluctuating (especially quality) when its known that your aerial is electrically sound as far as bad connections are concerned, then the problem is in effect out with your control, as its liable to be caused by either atmospheric reasons allowing distant stations to be picked up thereby blocking local reception, or that the problem is due to the intermittent effect of tree foliage blowing about, worse obviously if wet.
In both cases about the only thing a person can do is make sure that the signal being received is at a high enough level above their receivers cut off threshold whereby when the signal drifts downwards its still above the cut off point and not constantly dipping under it.
Occasionally moving the aerial a few feet either way (left or right) can help the situation, but frequently its at the expense of some other mux, so its really a hit and miss situation.
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M
Michael7:22 PM
London
Michael: Ah yes. The main TV is an old analogue one so has to be fed via SCART from a box with a digital tuner.
The other TVs in the house are digital, an LG, a Mikomi (Argos own brand?) and a Samsung borrowed from my father. The Mikomi was a bit iffy on Ch 22/23/28 muxes at times but the others were working fine.
I said "were", you may have noticed. The LG got really bad on those muxes a couple of nights ago, and the digibox has also started playing up. The Mikomi also got much worse. No footie for me last night!
Then today I switched off the distribution amplifier in the loft, expecting this to lose nearly all the signal. But no, the HD recorder worked fine. So too the Samsung and the LG, though later that started to be really bad on the Ch 26 mux. The Mikomi in the kitchen seemed to lose signal altogether, but at the main TV point it worked better than usual. So, for the first time, I was onserving differences between different TV points in the house.
The signal strength shown on the kit that can show it was a lot lower. Quality seemed more settled (and sometimes consistently high) - except where a tuner was having problems. The digibox is better, but not by much.
This does seem to suggest that the problem for the HD recorder was too strong a signal. But reducing the overall signal by switching off the amp seems to cause other kit problems, at least in some locations. Trying to amplify it at some points and attenuate it in others would surely be a complex trial and error exercise.
Every time I write this stuff up, something else occurs which does not seem to fit the pattern. I'm starting to think that the distribution amp is malfunctioning, particularly as the problems were not there until a few weeks ago. Deterioration of internal cable, perhaps?
Outside foliage seems an unlikely culprit, as next door, with a similar aerial (and similar Freeview via a box) setup shows nice level quality. The main change in the immediate locality has actually been the removal of a large pine!
The whole think s starting to make my head hurt!
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J
jb3811:11 PM
Michael: One particular thing you have said is extremely interesting, this being the results you obtained with the distribution amplifier switched off, because although distribution amplifiers boost the signal to varying degrees dependant on the spec of the model used, on the other hand when they (all types) are switched off they act like an attenuator having been placed in line with the aerial, this being why if done on an analogue signal it always resulted in a grainy picture.
The point about this situation being, that you must be receiving a reasonably good level of signal at your location for it to overcome the attenuation effect of an unpowered amplifier being in line, and so although I realise that you obviously require the distribution amplifier for purposes of feeding the signal to other locations its possible that the overall signal level created by this is slightly too high (for some devices) whereby an attenuator being placed in-line with the amplifiers "input" could help the situation, as an excessive level of signal displays exactly the same symptoms to one that's on the weak side, including "false" low signal indications caused by instability in the tuner.
I would therefore suggest that you try a test on one of the TV's by connecting its feed directly onto the aerial lead that feeds into the distribution amplifier albeit I do realise that in most cases this is a bit inconvenient to arrange, but though its the type of test that is necessary to evaluate what's happening.
Another point to note is, and although very unlikely to be applicable in your situation, but on "some" occasions when the signal quality is observed to be continually fluctuating this can also be due to a signal being on the verges of being excessively high, because signals in non line-of-sight situations tend to drift up and downwards in strength throughout a 24 hour period, and if they are hovering at the top end of high (with good quality) and they drift slightly further upwards then as soon as that happens the quality drops, this resulting in the fluctuations referred to.
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Saturday, 1 September 2012
J
jb387:33 AM
Michael: Just a small addition to that said, its not exactly unknown for a distribution amplifiers internal power supply to fail and especially during the warm weather, and so although what was mentioned about the amplifier still applies in every way its best to check that its still working.
The procedure is to have the amplifier switched on and carry out a signal strength / quality on a reasonably stable channel noting the readings, then connect the TV' aerial feed straight into the aerial and carry out a second check noting what the difference is, and provided an excessive level of signal is not upsetting the readings what's indicated with the direct aerial connection should be "slightly" lower than before.
If though its higher, then either the amp is defective or the signal level is excessive.
By the way, I will not personally be available to give further assistance until about next weekend as I will be on holiday, although someone else will probably answer any query you might have.
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M
Michael12:34 PM
London
Michael: Thanks, jb38. It was my experience with analogue which made me expect little or no picture, rather than a better picture, with the amp off, so what transpired was a major surprise to me.
I had wondered about putting an attenuator in line near the equipement but it would be guesswork as to how much I need.
Carrying TVs or other digital equipment up to the loft is liable to result in not having said digital equipment in working condition any more, which is one reason why I have not tried it yet. (Would a long cable down to floor level be expected to work? Think I've got some spare cable - without connectors - somewhere. I suppose that with a suitable connector - whatever it might be - I could connect each cable directly to the aerial as well.) The other is that the connections look awkward to me, and if there is a way of terminally messing up the cable, I will probably find it!
I think it is clear that the amp was amplifying the signal that the digibox and HD recorder were using, as the signal strength they show is markedly lower without and the signal has either been lost or is seriously degraded at other points. That's not the test you suggest, of course. I've been careful to say "amplifying the signal" rather than "working" because it might be doing so in a highly variable manner. If the PSU is giving a jerky supply, might that cause the behaviour I am observing? PSUs are usually presented as being specific to one device but I think I have a variable one knocking around somewhere, so it might be worth trying that (cue exploding amp in loft...).
Whatever is going on, it is something that has only been going on seriously for about eight weeks. As the aerial signal seems strong enough unamplified, and the kit I have tried elsewhere works fine, a malfuctioning amp does seem to be the fault that best fits the bill.
However, thinking about it, there have been some smaller, easily dismissed, deteriorations before this. In particular, I have a TV card in my computer connected to one point, and 9 times out of 10 I get a green mass of pixellation at the foot of the picture. Yet 1 time out of 10 it is fine! That's been the case since I got the computer a couple of years ago, but of course the cause could be completely, er, unconnected.
As it happens, I have even got the digibox working off the unamplified signal at the main point this morning. It does seem inconsistent, and I do worry that deterioration arising from the constant swapping around of cables might itself be an issue. I think I'll leave well alone for the weekend and see what happens.
Just for the record, there are four outputs from the amp, servicing five TV points. One of the cables must split out of sight; I think this is the one to the points which now seem dead, which makes sense as they would get the least signal at all.
Finally, thanks for all your help, and enjoy your holiday!
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Sunday, 2 September 2012
M
Michael1:43 PM
London
Michael: Just an update. Tested the power supply and it gives a steady 5 volts DC, as it should do. Suggests to me that it has to be the amplifier/splitter itself.
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Wednesday, 5 September 2012
M
Michael9:04 PM
London
Michael: Sorted! Aerial technician replaced the splitter/amplifier with a straightforward splitter, and eveything works.
He said that the aerial was actually picking up too much signal. Also that when I unplugged the splitter/amp, the improved (but still variable) signal seen on the main TV was being picked up purely by the cable between the splitter and the aerial point, that cable being high quality and (if it matters) outside the house.
This begs a number of questions (though I am not too worried now everything is fine). If the aerial signal was too strong, how did it work before? My guess is that when it was working properly the amplification was less than the attenuation provided by splitting. At some stage it stopped splitting the signal properly, hence overload on some aerial points and poor or no signal on others. But what do I know?
Anyway, I have to eat humble pie about blaming it all on the Crystal Palace signal.
The other question, I suppose, is why the excessive signal was not diagnosed by the earlier technicians I had in. In their defence, things seemed to be working OK that morning, and the deterioration at other times was less than more recently; they only checked the output at one aerial point as well, rather than the input to the splitter.
So long and thanks for all the fish...
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