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 22/05/2023 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 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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Wednesday, 26 December 2012
J
jb389:51 PM
K.Barrett: I had also meant to add, that as Chiseldon is located so close to your area of residence then I wouldnt really bother too much about what band of aerial you are using as it doesnt really matter, but though its the fact that you also experience problems with Chiseldon that is the main thing to look into, and along the lines of ensuring that the relay is not just repeating a problem inherited from Mendip.
By the way, although no transmitter engineering should be taking place over the Christmas period faults can still occur on the transmission (relay) side that may not be instantly known about, and so it should not be automatically assumed that the station has a clean bill of health, so to say.
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K
K.Barrett10:16 PM
Question: if I do consider upgrading the aerial what should I buy? The upgrade path for Mendip as the 800MHZ band is cleared isn't obvious.
Will the powers that be really force those of us in fringe areas through an upgrade path possibly involving multiple aerials, filters and diplexing or will a new aerial be designed that focuses on channels 21 - 59 and not tuned for the 800MHZ range?
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K
K.Barrett11:41 PM
If, as I expect, my neighbours are experiencing the same problems (Mendip and Chiseldon relay freezing on BBC) who do I report it to?
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Thursday, 27 December 2012
J
jb3812:01 AM
K.Barrett: These are lots of myths around about aerials used for DTT reception and if one is required to cover the channels mentioned then it has to be a wideband version, but though NOT one of the high gain varieties in your situation as high gain (or so called) aerials rely on being precisely focused on the signal source, this being something that cannot really be achieved in circumstances such as yours and so using one of these types will give a slightly inferior performance (glitch wise) over that a wider acceptance angle type coupled to a booster of around 15db or so minimum.
Taking this into account I would recommend using a log 40 in conjunction with a variable booster of around the rating referred to, as should less than satisfactory reception be evident with this combination then I can say with a level of confidence that nothing will improve the situation, and with this basically being because that the problem is outwith your control.
This is a link to the type of aerial referred to.
Online TV FM DAB Aerial sales
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K
K.Barrett12:01 AM
Further thoughts on interference.
If it is local RF interference (however caused) it only affects the following channels (frequencies):-
Chiseldon = 27 (522MHZ)
Mendip = 61 (794MHZ)
With all other Channels (frequencies) on both transmitters being rock solid it must surely be a problem between Mendip and Chiseldon transmitter.
Wouldn't local interference be too much of a coincidence to affect only two frequencies and both those to be the ones transmitting or relaying BBCA and some 270MHZ apart without affecting anything in between.
If it is local interference then I think it is time to call the experts as looking at it like this I am certain my neighbours will confirm they have the same problems.
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K
K.Barrett12:19 AM
jb38: Thank you for the advice. We do suffer very windy conditions here as it is high and very exposed will this rear fix aerial safely mount - I guess I rely on my installer for advice.
Will the very directional nature prevent use of the XB22WB and why is it so hard to get it perfectly aligned?
While Mendip is obscured if my aerial was 15m above ground level then it would have line of sight so that obscuring is only slight. (Checked on megalithia.com)
Some aerials here do point at Oxford and that is far more obscured than Mendip.
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J
jb3812:49 AM
K.Barrett: Well I wouldn't rely too much on these terrain predictors as they take no account whatsoever of anything other than ground level, and so a person could be located behind such Sherwood Forrest or a number of tower blocks and yet it would still indicate a clear line of site.
As far as the XB22WB is concerned, all I can say is to give it a try, but though when a person is located in a difficult reception area then the secret is to try and have an aerial with as wide an acceptance angle of pick up as possible to compensate for the inevitable deviations in the angle that the signal is received at, then make up for the slight less gain by using a booster of the rating referred to.
After all it has to be appreciated that the only reason an aerial can be classed as high gain is because that the multitude of director elements located along the boom focuses the signal on the only active part of the aerial that exists, this being the element immediately in front of the reflector, whereas with log aerials all elements are active and thats why their response across the bands is so even when compared to other types of aerials.
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J
jb388:18 AM
K.Barrett: I was just reading through your various postings again and in particular the one made at 11.41pm, should it transpire that your neighbours are also suffering from similar problems to yourself then if at all possible try and check at some location outwith your immediate area, maybe even a shop or store that sells TV's and such likes, but the main point is to be able to verify if the problem only exists in your immediate locality.
That said though, as far as interference is concerned if the problem is definitely only affecting the BBC transmissions then I very much doubt if its anything connected to local interference, as in my opinion (as an engineer) I feel that it would be a bit too coincidental (although not completely impossible!) for the BBC to be involved in both cases when two separate frequencies are involved, unless that is it was actually them at fault! because I remember a case some time ago in a Northern area of Scotland where an intermittent fault existed on a relays HD transmitter for nearly a week, this being because that the problem hadn't been noticed by the fact that it wasn't a complete breakdown in transmission.
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Thursday, 3 January 2013
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