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 05/06/2023 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, 11km north-northwest (334°)
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 TV region BBC London LondonWhich companies have run the Channel 3 services in the Crystal Palace transmitter area
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Thursday, 10 May 2012
J
jb3812:33 PM
Alan Tuthill: Go into the signal checking screen and observe the mux channel number thats shown associated with the strength / quality indication, if Ch26 its Crystal Palace whereas if Ch42 its Hannington, the only other alternatives are so low in level that its doubtful if they would be received.
By the way the BBC match for these channels is Ch23 (C/P) and Ch45 (Hannington).
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T
Tony8:05 PM
jb38: Thank you for your detailed analysis of my situation.
I will try what you suggest and take the attenuator out of the system and measure the reading on the Horizon meter straight from the aerial. I have to say that, as you also suggest, I was expecting a much higher db reading after switchover since the wattage should have gone up to 200,000 watts. It occurs to me that the Horizon meter might be limited to what it can display - so I'll contact Horizon to ask that question.
To switch my aerial around to Sudbury I would need to get a tv engineer out and that is out until I establish the true state of affairs.
FYI, I am using BlackGold BGT 3620 cards in my WMC PC.
I'll get back to you when I have tested the points above. Sigh.....
Tony
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Friday, 11 May 2012
T
Tony5:52 PM
jb38: Okay. I think I've got the story straight.
Firstly, I've been abit of a klutz and was not reporting the correct signal category from my Horizon meter. What I should have reported is as follows:
Channel dbuv
22 56
23 59
25 60
26 62
28 63
These values, which are direct from the aerial, seem to be well over the value predicted by the 'UK digital TV reception predictor' which suggests the normal value to be 46. So, it looks like there is nothing wrong with my setup. I have now removed the attenuator and a couple of splitters I had in my system. The readings after the signal has been distributed by the Labgear splitter are as follows:
Channel dbuv
22 63
23 64
25 65
26 66
28 67
The SN readings from the Horizon meter are showing no errors.
I telephoned Horizon and spoke to a very helpful chap who indicated that HD reception will never give the same signal qualities as standard channels - he said that some meter manufacturers fiddle the signal scale for HD channels to make it seem that the signal qualities are the same for standard and HD channels. He thought that a signal quality for HD of 60% compared to 100% for standard channels is about right.
Does all this make sense to you?
Tony
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E
Edward Horne6:07 PM
I have now resolved the issue.
Starting on the 8th roadworks were started close to the property. The traffic signals put in place use radio signals between themselves to control their timing. These signals have been causing interference.
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CRYSTAL PALACE transmitter - Over the next week Crystal Palace main transmitter: TV (digital) working normally, Radio (analogue) Possible weak signal, Radio (digital) working normally. [DUK]
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CRYSTAL PALACE transmitter - Over the next week Crystal Palace main transmitter: TV (digital) working normally, Radio (analogue) Possible weak signal, Radio (digital) working normally. [DUK]
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J
jb389:42 PM
Tony: Well unless you have the HTDM-T2 version then what he has told you doesn't really make sense, because unless I am mistaken the older HTDM or plus types should not respond at all to an HD signal, this in the same way as applies with all standard Freeview receivers, insomuch that if you try to manually tune in an HD channel and the device you are using only has a DVB-T tuner (SD) then the result will be a "no signal received" message even although the HD signal might be belting in.
The other point is, that I was doing some checking on the BGT 2630 and discovered that there are a number of issues with it for a variety of reasons and with mostly all concerning HD, a users comment seen on the link (below) referring to an offset frequency having to be manually entered for HD albeit this action not being necessary for SD, I didn't go into it in detail but its the fact that it was mentioned at all that's important.
With the new found knowledge of the problems some people experience when using that card it somewhat reinforces what I had previously mentioned insomuch that you are assessing performance purely on what you see with the card, and so its essential for your HD signal to be tested on a more standard device other than this (e.g: a Freeview HD box etc) as you could be spending no end of time trying to compensate for something that's caused within either the PC card or the PC circuitry itself.
By the way, these updated signal readings you have given are very much better and indicate indicate perfectly OK, especially the aspect of zero error rate, cant beat that!
These are only two examples of what was seen mentioned. (you will likely have to copy and paste them into the browser)
Windows Experts Community
An original review referring to minimum specs for PC's etc when using the card.
Black Gold BGT3620 review | from TechRadar's expert reviews of Tv tuner cards
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Sunday, 13 May 2012
T
Tony7:42 PM
jb38: Thank you, again, for a detailed response.
I don't have a HDTM-T2 monitor and I cannot check the HD signal strength except by using what WMC reports. The Horizon expert indicated to me that I should not expect a signal quality of 100%, as, he says, no-one will get that for HD for freeview terrestrial. I cannot comment on whether or not this is really so.
The issue you mention about the BGT3620 card isn't as problem with the card but a 'feature' of WMC for Windows 7 where WMC scans and loads channels from multiple transmitters. This means that there may be several sources for each channel. It then is necessary to manually remove all sources that reference frequencies for transmitters that you don't wish to use. This process is incredibly tedious. As it happens, I am a .NET developer and have written a windows application to manage this issue very easily - it removes all sources whose signal quality falls below a user defined threshold in less than a second. So I have overcome this issue.
Anyway, the main thing is that I do appear to be getting a better than adequate signal from Crystal Palace and do not need to call in a TV engineer.
Thanks for all your help.
Tony
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N
NICK ADSL UK 9:23 PM
Tony the only experts are the ones like JB/mike.Brian/and myself having said that my expertise is a little different in i know a duff storey if i was told one and regretfully you have been told one
I get a 100% for quality and strength as that's what I'm about as a person always going the extra mile to perfect something just like the old Japanese days
Sadly today thou those days are over but none the less i still aim for perfection in everything i undertake
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Monday, 14 May 2012
M
Mike Dimmick6:44 PM
Tony: It depends whether the device is reporting error counts (or 100% less error count) before or after the two stages of error correction. Most Freeview boxes, and PC cards, report quality statistics after both stages of error correction and are therefore completely useless for setting up for best reception.
The HD-TM does show pre-Viterbi error rates and an indication of carrier-to-noise ratio. You should adjust your system to minimize the pre-Viterbi BER. Before switchover it was generally recommended that you should keep digital signals in the 45-60 dBuV range, after switchover you can probably add a bit more headroom (this range was recommended to keep the *analogue* signals, typically 10-20 dB louder than the digital ones, in the 60-80 dBuV recommended range.)
TVs, boxes, tuner cards and dongles usually don't display pre-Viterbi statistics as the decoded signal has to be re-encoded to compute them, which requires extra logic.
Raw bit error counts for HD signals will be greater than for SD signals, because the HD mux carries approximately 66% more data. Still, they should be about the same order of magnitude. They're more normally quoted as rates, number of bits in error compared to the total number of bits, which should be about the same.
Be aware that BER is quoted in exponential notation and it's a very small value. A larger exponent (the value after the E) is *better*, not worse. 1E-4 is 1 in 10,000, 1E-6 is 1 in 1,000,000. "Quasi-Error-Free" is given in the DVB-T spec as a figure of 2E-4 *after* Viterbi decoding (i.e. post-Viterbi).
I'm not sure which predictor you're using. Digital UK is the only one I know of that uses correct data (mainly because the broadcasters are the only ones that have all the necessary data) and correct algorithms. Digital UK's figures are percentage of locations within your grid square that are expected to have sufficient margin for 99% of the time (50% for the second column), they are not field strengths or terminated voltages. Wolfbane is widely considered to give results that are too low; even so, the predicted values given are electric field strength in dBuV/m, not terminated voltages in dBuV. The conversion is related to the aerial's dimensions and gain.
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