Full Freeview on the Mendip (Somerset, England) transmitter
Brian Butterworth first published this on - UK Free TV
Google Streetview | Google map | Bing map | Google Earth | 51.237,-2.626 or 51°14'12"N 2°37'33"W | BA5 3LB |
The symbol shows the location of the Mendip (Somerset, England) transmitter which serves 720,000 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.
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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 Mendip 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 Mendip transmitter?
ITV West Country News (East) 0.9m homes 3.4%
from Bristol BS4 3HG, 23km north (11°)
to ITV West region - 61 masts.
All of lunch, weekend and 50% evening news is shared with West Country (West)
Are there any self-help relays?
Cheddar | Transposer | 15 km E Weston-super-Mare | 1674 homes |
Luccombe | Active deflector | 6 km w Minehead | 38 homes |
How will the Mendip (Somerset, England) transmission frequencies change over time?
1984-97 | 1997-98 | 1998-2010 | 2010-13 | 2013-18 | 2013-17 | 27 Feb 2018 | |||
C/D E | E | E | C/D E | C/D E T | W T | W T | |||
C30 | _local | ||||||||
C32 | BBCA | ||||||||
C33 | com7 | com7 | |||||||
C34 | D3+4 | ||||||||
C35 | com8 | com8 | |||||||
C36 | ArqB | ||||||||
C37 | C5waves | C5waves | |||||||
C48 | SDN | SDN | SDN | SDN | |||||
C49tv_off | BBCA | BBCA | |||||||
C51tv_off | LBS | LBS | |||||||
C52tv_off | ArqB | ArqB | ArqB | ||||||
C54tv_off | C4waves | C4waves | C4waves | D3+4 | D3+4 | D3+4 | |||
C55tv_off | com7tv_off | ||||||||
C56tv_off | ArqA | ArqA | ArqA | COM8tv_off | |||||
C58tv_off | BBC1waves | BBC1waves | BBC1waves | BBCB | BBCB | BBCB | |||
C61 | ITVwaves | ITVwaves | ITVwaves | BBCA | |||||
C64 | BBC2waves | BBC2waves | BBC2waves |
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 24 Mar 10 and 7 Apr 10.
How do the old analogue and currrent digital signal levels compare?
Analogue 1-4 | 500kW | |
Analogue 5 | (-6dB) 126kW | |
SDN, ARQA, ARQB, BBCA, D3+4, BBCB | (-7dB) 100kW | |
com7 | (-8.4dB) 72.4kW | |
com8 | (-8.6dB) 69.1kW | |
Mux 1*, Mux 2*, Mux A*, Mux B*, Mux C*, Mux D*, LBS | (-17dB) 10kW |
Which companies have run the Channel 3 services in the Mendip transmitter area
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Friday, 5 April 2013
J
john9:33 AM
Here's a list of what my Humax box gives
ch 56 signal 71% quality 100% 18 channels
ch 54 signal 72% quality 100% 8 channels
ch 52 signal 55% quality 100% 30 channels
ch 49 signal 27% quality 10% 0 channels
ch 48 signal 17% quality 10% 0 channels
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R
Rob 10:17 AM
Since the retune i've lost all BBC channels. perfect signal on all ITV, Channel 4 and remaining freeview channels. have reported to Digital UK via email and on the phone. My partners pub (a mile down the road) has also suffered the same problem.
The repsonse? There are no reported problems! Been advise that I can contact the BBc directly and they will send out an engineer but they will charge for this service!
Great! Why is it that the only TV service I actually pay for (the licence fee) is the only one I cannot watch?
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Michael Perry
2:48 PM
2:48 PM
To Rob and John
Did this only appear after the transmitter work early morning on March 27th?
Might be receivers not recognising that BBCA Mux has moved (my Hauppauge lost BBCA and had to be completely reset) so worth trying a full retune as if you are doing a fresh install but you may need to do a factory reset as well before the retune. Doesn't always work though.
Another possibility if it has always been poor on COM4 channels (see top of page) then you may have aerial/feeder problems so that reception of Chs 48 & 49 are too poor to be decoded properly.
Can you both indicate where you are in relation to the transmitter as Huntshaw Cross is known to cause some problems if in same line of sight.
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J
jb385:17 PM
Mike: Well although I did realise that you had already replied to Michael Perry with regards to having tried everything in the manual I just wanted to verify that this also included the "first time installation" option as you hadn't actually mentioned that, as this is about the only action that can be taken on that model guaranteed to wipe the tuners memory free of anything that may have previously resisted deletion.
However, I do agree that the aerial system referred to certainly requires to be checked out for any possible defects, as judging by the indications seen on the terrain indicator (Megalithia) no-one in your area can afford to have any deficiencies in the aerial department, because even excluding recent events I would expect reception for those who reside in the area to be of a variable nature at some time during the year, as on checking the signal path over the 39 miles or so from the transmitter its seen pass over ground at a relatively low angle from about 4 miles out as well as finally experiencing a blockage at 2.5 miles or so from your location, but with these indications excluding trees as well as man made objects the result of that indicated could actually be worse.
Reception under these type of circumstances will also usually suffer from being affected by seasonal changes related to climatic conditions as well as vegetational reasons such as trees, and even although a person might well "appear" to be having good reception the actual signal / quality level is likely to be sitting at not far above their receivers cut off threshold level, but with this fact not really being noticed if the quality is reasonably stable even although the actual signal strength might be weak.
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Mike
6:35 PM
Worcester
6:35 PM
Worcester
jb38: Many thanks for your suggestions. You are so right about seasonal variations. Some people near-by get a better signal from Ridge Hill or even Malvern. We are right down at sea level too. So the diagnosis is leading to low signal strength combined with a difficult to reset tv, that now has a less than adequate signal.
Thanks for your help. Mike
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Mike's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
Michael Perry
8:49 PM
8:49 PM
Hi Chloe
What have you tried and what equipment are you using? Plus what area?
The transmitter at Mendip is not faulty and is radiating a proper full strength set of programmes in the BBCA multiplex (thats all the BBC TV and radio services apart from the HD ones) and all the others as well.
So we need to help you find out why your equipment is not showing the programmes, hence the request about equipment, location, etc.
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C
chloe9:50 PM
We have a panasonic tv which we have reset to factory setting almost on a daily basis to try and gain a signal, we have tried manually retuning channels 48 & 49 both showing nearly no signal or quality, we have a single aerial on our roof which was only installed a few years ago. We live in Taunton and had no problems before the 27th.
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J
jb3811:18 PM
Mike Perry: Although the Philex signal meter referred to in the link is a well designed little device than can under certain conditions serve a useful purpose, but the main problem with any of these devices is that they are incapable of measuring the most important aspect of any digital signal, that of its quality, and with this deficiency being something that can be a real impediment if the device is being used in a somewhat iffy reception area.
The reason for this being, that these type of devices work in a similar fashion to that of the low cost satellite types which are in effect not much more than an amplified RF sniffer device but fitted with a band pass filter, the difference when using satellite types is that although they also only give indications of strength its not just so important because the quality associated with a peaked sat signal is never that far away (if at all) from the strength when checked on a proper meter, or alternatively the sat boxes signal check screen, this simply being due to the fact that sat reception does not suffer from near the same level of variables that can exist with a DTT signal when being received in non line of sight situations.
This lack of a DTT quality indication can create a situation where a person attempting to align an aerial can possibly be pleased with themselves at witnessing a 70dB signal being indicated on the meter, but unknown to them with that level only being accompanied with a very low quality to the extent that any subsequent scan carried out might not result in a workable (or any) signal being received, this I am sure causing a great deal of frustration to the person attempting to align the aerial and who no doubt will be mystified by this. That said though, if they carry out a manual tune (equipment allowing) mux check this problem will soon be revealed if the TV or box used is capable of displaying a signals quality as well as the usual strength.
By the way, the reason that none of these low cost devices can differentiate between muxes is simply because that for any device to be capable of doing that requires it to be fitted with a tuner / decoder similar to that used in a Freeview receiver, although by the device being designed for accurate signal measuring purposes it has to be of a somewhat superior circuitry as far as stability is concerned, and with a price tag to match.
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