Full Freeview on the Mendip (Somerset, England) transmitter
 | 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.
Are there any planned engineering works or unexpected transmitter faults on the Mendip (Somerset, England) mast?
Mendip transmitter - Mendip 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 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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Saturday, 5 April 2014
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Iain Davies5:15 PM
The saga continues, having failed to get CH51 through the distribution amp I thought I could feed the signal to a least one other room via the loop through using a Blu-ray recorder to be used with the main TV but even this blocked the signal for CH51. Again all other channels HD & SD no problem, I still think they don't want this channel distrubuted.
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J
jb388:17 PM
Iain Davies : Provided that you are within the coverage area of the directional C51 transmission then nothing of a technical nature can be done at the transmitter to stop anyone from receiving it, however could you please confirm (or not) that when you fed the signal into your Blue-ray recorder for the purpose of looping through into your TV that it was coming directly from your newly installed aerial? and that you can actually view the programme "content" (not just signal) on C51 without the amplifier in circuit.
It would also be of assistance as far as signal level assessment at your location is concerned if you could provide a post code from somewhere located nearby, plus it would also help to have knowledge of the distribution amplifiers model number and is this a newly acquired item? because apart from that said in your update the problem could be suggestive of either the amplifiers input being overloaded or even a fault in the devices input circuitry, especially when more than one device is seemingly being affected.
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Iain Davies9:56 PM
Jb38, any TV feed directly from the aerial is OK all channels show 100% quality and 100% strength on the Blu-ray signal meter. Only when you add the distribution amp or try to loop through the Blu-ray recorder you lose channel 51. All the TVs and Blu-ray reconder are Panasonic (no rubbish)! I have also tried a Humax HD fox T2 with the same results.
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Sunday, 6 April 2014
J
jb3811:18 AM
Iain Davies: Although I still feel that its a bit unusual for signal overload symptoms to suddenly appear on all of your devices by simply changing the aerial, that is unless the one you were using was grossly inefficient!, however now its known that all of your devices are of the same Panasonic brand (my main TV being same) then its likely that their level of susceptibility to signal overload conditions (swamping) will be roughly the same on them all, whereas not the case with different brands.
As far as the Blue-ray recorder is concerned, passing the signal through its loop-through facility does not usually result in any amplification of the signal (or very low if it does!) although it would have been of interest to know if the C51 signal could be picked up by the Blue-ray recorders tuner before being fed into the TV via the HDMI connection rather than just using the device as a loop- through facility.
Although still being unable to assess the signal level expected at your location, but dependant on where your distribution amplifier is sited you should try a test using either a set top aerial or a short length (about 6' or so) of wire connected into its aerial input socket to see if this results in C51 appearing, if it does then you will have to purchase an attenuator such as that seen on the link and use it in line with the splitters aerial input socket, or alternatively purchase another splitter but of the passive (non-powered) type.
Just a little point about Panasonic's, the strength level indicators on these devices are inclined to be over lively compared to the reality of the situation, Humax being more in line with the actual, but should the Humax also indicate a strength of 100% then the signal level "is" excessively high.
TV Aerial Attenuator Variable 0-20Db Freeview Digital | eBay
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Iain Davies5:01 PM
Jb38, thanks for all your help. I have come to the conclusion I'm just going to feed each TV with it's own aerial, as I have spent 3 days now messing about with this. There is no problem using the Blu-ray recorder's RF in and via HDMI to the TVs.
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J
jb388:05 PM
Iain Davies : Fully appreciating how frustrating this type of problem must be, but though it does have to be said that faults of this nature are seldom ever cured except by trial and error and with the person suffering from usually having to make some minor purchase, and if your signal is as strong as what your report would suggest then its either a variable attenuator to place in-line with the input to the distribution amplifier, or alternatively to do away with the powered splitter and replace it with a passive version which also gives an element of attenuation to the signal.
But though, and as mentioned on a couple of occasions, its not possible to estimate the level of signal expected in a particular area with any degree of accuracy without having knowledge of a post code from somewhere nearby, as this then gives access to the reception predictor plus more importantly (in some cases) the terrain indicator.
Anyway, purely for information purposes the undermentioned link is for a relatively inexpensive 4 way passive (non-electronic) splitter of the coaxial connector type, screw "F" connectors being the norm for this type of device.
Wellco 4 Way Aerial Splitter Allows 4 TV's or other: Amazon.co.uk: Electronics
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Monday, 7 April 2014
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Iain Davies7:36 PM
Jb38, it just seems very strange that the high power MUXs are OK its the low power "local" channel that is giving the trouble. I could understand if the 100kw channels were giving an overload, not the local Channel at 10kw!
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J
jb389:23 PM
Iain Davies: Yes, but its not the low powered 10Kw LBS that is overloading the tuner, but the swamping / desensitizing effect caused by the 100Kw main transmitters resulting the tuners auto gain circuit coming into play to avoid instability, the side effect of this being that it makes the tuner less sensitive to weaker signals whereby causing them to drop under the threshold level required for reception, hence they vanish!
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Tuesday, 8 April 2014
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