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 28/10/2024 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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Monday, 11 June 2012
N
NICK ADSL UK 4:14 PM
There's just one other thing that i have just come across in that all leads that go into equipment need to be of quality as most leads do have a habit of starting out OK but then if moved or touched losing the connection for some odd reason
So it's vital that you use leads of a high standard to rule this out
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M
Mike Dimmick5:56 PM
Steve: Signals from plain dipoles are diffused in a ring-doughnut shape. With more tiers of panels connected in-phase with each other, you get more gain in one plane and a number of additional smaller lobes. There are some angles that would indeed get no or nearly-no signal, referred to as nulls. The antenna designer therefore adds small differences in the lengths of the connections to each panel, which has the effect of reducing the nulls, at the cost of some efficiency. This is called 'null filling'.
Also, the main lobe of the transmitted signal would normally be exactly horizontal, which - due to the curve of the earth - actually misses the ground completely. Again, the changes to the relative phases allow this to be adjusted down a bit so that the peak signal lands at a reasonable point just short of the horizon - this is called 'beam tilt'.
Both null-filling and beam-tilt adjustment are performed to ensure that even those living very close will get sufficient signal. It will be less than the full 200kW, but people living this close do not need anything like that amount of power.
We don't have the design for the current transmitting aerial, but the BBC report for the old analogue aerial, with graphs showing its performance, is available at http://downloads.bbc.co.u….pdf . The vertical radiation patterns are on p13-p15 (figures 10-12). One-tenth or one-twentieth of the field strength is still very high indeed, there are many local relays intended to serve areas 1-2km away from the mast that have less than 100W. There are transmitters with less than 2W output, indeed there are some 'Link' sites with less than 1W, although these are really to get the signal to another relay . People that close to CP are more likely to have too much signal than too little.
As for the leaves: I believe they're more effective at blocking radio signals at UHF than your walls are, because they're mainly water (even worse when wet leaves). They also move in and out of the path when the wind blows, making for a lot of additional variation.
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J
jb388:38 PM
martyh: With regards to your query as to whether it matters what make of adaptor is used, I have to apologise for missing that posting and which on searching back I see was made on April 25th @ 7.41pm, although I would always advise anyone thinking on purchasing any digital receiving equipment to avoid the cheap end of the market, the Konig I used for an example not being as well as having a reputation for good performance, albeit of course as with all digital equipment there will always be someone with a problem.
However, on studying what you have reported I see its really a case of you having two separate issues, that of the picture ratio being incorrect plus that you cant find a happy medium when trying to balance out the colours etc on the TV. Your TV has four ratio modes 16:9 / 14:9 / 4:3 and Auto format, so what happens if you leave it on Auto and try a combination of settings on the logic? because to put it in a factual way a satisfactory outcome can only be achieved by experimenting with the setting options offered on the device as nothing external can be done to alter this.
This also applies to the issue of the colour / contrast / brilliance etc settings, as you really have to start afresh with these settings due to the fact that all of your original picture settings were made to suit the sets internal circuitry, and so just like as with the issue of the screen ratio a satisfactory solution has to (and can only) be achieved by experimenting with the settings offered on the TV, because this problem just like as with the picture format issue, can only be rectified via the range of settings offered on the TV's menu
That said, it would be of interest to know what kind of results would be achieved if you temporarily tried the Logic on another TV, as that would soon reveal if there was a problem with the device, as to me anyway, the quirks associated with particular Logic device is an unknown quantity.
Finally, regarding the aerial link from the Logic to the TV, you can really leave that permanently disconnected as you are in effect only using the TV as a monitor anyway.
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Tuesday, 12 June 2012
S
Steve9:25 AM
Mike, Thanks for your detailed explanations and answers to my questions - the null filling and beam tilting is most interesting - I guess there must be an optimum distance between the transmitter and the horizon where reception is just about right. Not too close and not too far. So neither attenuation nor booster needed.
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Mike Dimmick: Thanks for the insight. I have some questions for you which I will be grateful if you can answer.
The PSB networks are different to the COM ones, coverage wise, with the latter being more restricted due to channels being re-used more often (distance wise from transmitters). I have seen that you have said that coverage is generally more often restricted by interference than propagation. Helping out on this site, I have seen a number of occasions where this has been seen to be so.
Some transmitters have COMs at the same ERP as the PSBs, but according to predictions, their will be some viewers who will only be able to pick up the PSBs. (See Freeview news | ukfree.tv - independent free digital TV advice )
Referring to the Arqiva "Reference Offer for the Provision of Network Access" (page 29), Emley Moor uses two sets of panels, one for PSBs and one for COMs. Both have an ERP of 174kW. Is it likely that the COMs antenna's beam is tilted lower than the PSB one (which might account for the difference in number of people served for each)? At my location, the COMs appear lower strength and turning the aerial off-beam, when the COMs start to break-up, the PSBs are still strong.
http://www.arqiva.com/cor….pdf
Then there are those whose COMs are at half-power to the PSBs. Midhurst is one such example and its Steyning relay currently broadcasts co-channel with two of Midhurst's COMs. This is an example which illustrates why the COMs are more restricted.
Midhurst isn't shown in that document, so take Stockland Hill as an example. It apparently uses one antenna system for all six muxes (all of which are in the 20s) and the COMs are at half the power of the PSBs.
Why do some transmitters have two antenna systems and some have one? I appreciate that where channels are far apart they are likely to have to have more than one. I presume that the tilt of the beam will be the same for Stockland's PSBs and COMs as it's the same antenna.
Is the answer to the question cost and the fact that there's little to be gained having different antenna systems with smaller transmitters and that reducing ERP is a much more effective (from a cost point of view) in restricting coverage?
Then there is Belmont. The PSBs are in the 20s at 150kW, COM4 is on C30 at 50kW and COM5 and COM6 are on C53 and C60 at 100kW each.
Obviously C53 and C60 can't have as big a footprint as the PSBs as these are re-used from Oliver's Mount, for example. Some in Filey receive from Oliver's Mount and some, including those low-lying on the sea front, receive from Belmont. So there is clear overlap.
The reason I mention Belmont is because of the apparent anomaly of COM4 being half-power to COM5 and COM6. Why is this?
According to the Arqiva document, the three PSBs and COM4 use one antenna system and COM5 and COM6 use another. This makes sense due to the channel spacings.
Is the reason that C30 is at lower power so that the signal doesn't carry as far (as it's being radiated from the PSB antenna)? And again, for cost reasons: instead of having three antenna systems; one for PSBs, one for COM4 (lower power and lower tilt that the PSBs) and another for COMs 5 and 6?
I am wondering if it is cheaper to restrict coverage by reducing ERP (for COM channels) whilst using the same antenna as the PSBs (e.g Midhurst, Stockland and Belmont COM4). But for the larger transmitters it is more financially viable to have two antenna systems, even where all channels are close to each other (e.g. Emley Moor and I presume Crystal Palace).
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Wednesday, 13 June 2012
M
martyh10:38 AM
ok jb38. Will be able to try your suggestions towards the end of the week.
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Saturday, 16 June 2012
M
martyh10:48 AM
jb38. Had a chance to mess around with all the settings on my TV, plus the logic adapter. Have tried every combination I could think of without success. Point to note, when I first rigged up the logic, there were no issues that I remember regarding the picture not filling the whole of the screen area. I only watch TV occasionally at the weekend, and in the first 2 weekends, it was fine. It's only the last couple of weeks that the picture has played up, so am stumped as to why things have changed. Could it be that a week signal may result in some information not reaching me, or that maybe some information is missing from the signal? Seems strange it was ok at first, and now it's not. Point to note, I also tried swapping the logic using the 3 different scart sockets (EXT1, EXT2, EXT 3) on my TV, and noticed that the frames of each differ ever so slightly in terms of positioning. ie: one would move slightly more to the right, or to the top etc - however still all leave too much gap at the top and to the right (as per original post/problem). The natural position re: picture for my TV, is when set to auto, and this has never presented any problems - including when I first used the logic, So I am wondering if for some reason the logic cannot process all the signal information, as maybe it's missing or not all of it is reaching me? Only have one TV, so cannot test with another - also neighnours mostly have skysat or cable, so cannot varify/test with them.
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M
martyh12:05 PM
jb38 UPDATE!!! Dead phosphors/'pixels'? Have physically looked at the TV screen and inspected it! I am now wondering if some of the display phosphors are dead. On observance of the screen (when TV off) I see the main picture area coloured a grey/green, with the outer edges in black. The grey/green area does appear to have shrunk (in effect) as they do not extend all sides, to where they were originally, thus leaving larger areas to all sides in black, than used to be. (if you see what I mean), so my suspicion now is that there is a fault with my tube (ie it's on the way out), rather than anything else. If you concur on this, I wonder if you'll agree that this is a most strange coincidence. ie. That within weeks of me using the logic, a fault has occurred with my TV screen? How bizarre is that!
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P
Peter12:44 PM
Does anybody else wish that the TV industry would move away from using coaxial plugs and sockets, the poor quality of which often leads to reception issues, and towards better quality, more professional connectors?
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T
Tim2:21 PM
Radlett
Peter, I agree with you, I use F connectors for all my RF connections
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Tim's: mapT's Freeview map terrainT's terrain plot wavesT's frequency data T's Freeview Detailed Coverage
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