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 15/04/2024 Pixelation or flickering on some or all channels 
_______
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
|
|
Saturday, 7 July 2012
C
Chris.SE4:02 PM
Charles Stuart: Another thought I've had is that since you have moved from Kettering, if any of your equipment has RF outputs, you may well need to re-tune them to other channels as the ones you have, or may be some wierd combination depending on what is switched on may cause interference with reception of the Mendip channels.
Depending on what you have I'd suggest trying channels above 62.
| link to this comment |
C
Chris.SE4:10 PM
@jb38
knowing the location, the postcode I provided in my post at 1.27pm is a nearby one. Also considering the "description" of his external aerial (sounds like a 10 element yagi) it is highly improbable that he has too much signal.
| link to this comment |
C
Charles Stuart4:45 PM
The RF signal doesn't seem to be a problem, though I have changed the output on the bedroom TV's box (an Icecrypt) to channel 30.
This site seems to change my post code into coordinates. It is BS15 1EF and the house has a nice clear view towards the transmitter. I think that the aerial has fewer than ten elements. My guess is five or six. (51.4634,-2.5264)
| link to this comment |
B
Ben Ward6:02 PM
jb38, I am posting part way through my latest attempts to sort myself out :-)
I reset my Panasonic back to factory condition etc. as you suggest above. It didn't help sadly. I have noticed that when I do an auto setup or rescan for channels, the system defaults to 'Channel 21' - isn't it meant to be 'Channel 61' for this part of the world?? How do I change it as it seems stuck?
I will tackle the next part of your suggestions this coming week, powering down the 4 way aerial splitter.
nb Sorry if I wasn't clear before, I don't have a second rooftop aerial, all F.V. boxes are and have been supplied from 1 signalfrom our only aerial with a splitter in the attic. One of those signals is further split in 2 for the downstairs (main) TV, to the Humax and (when it was working) to a Sony VTX-D800U.
Regards.
| link to this comment |
C
Chris.SE6:29 PM
Bristol
How odd with the postcode, I've put your postcode into my details for this post, so you'll be able to click on the links on the RHS of the post for your information.
As far RF outputs go, the lowest channels possible or above 62 should be ok. If you use above 62 you might have to adjust them in the future when that part of the band gets used for Mobile stuff.
Where C is the channel used for RF you can sometimes get interference on the following C+1, C+5, C+9. But as mentioned earlier, if you have several, sometimes there can be weird coss-modulation products as well, so there may be an element of trial & error.
Have a look on the Aerial link that jb38 gave and see if you can identify yours from there. If it's one of the most common, there are pictures about 2/3 down the page where aerial polarisations are shown or further down - contract aerials. I suppose it might even be a 5-bay X-beam if the directors look like X's.
If all your multiplexes are OK now, you may as well forget the previous problem, the multiplex could have been off-air for a short while and it wasn't reported or you may have had a brief spot of local interference. It's unlikely to be cable degradation as the HD mux on Ch.58 and the BBCA mux on Ch.61 (both higher frequencies)seem ok and higher frequencies are usually affected first.
Hope that helps.
| link to this comment |
Chris.SE's: mapC's Freeview map terrainC's terrain plot wavesC's frequency data C's Freeview Detailed Coverage
J
jb388:11 PM
Ben Ward: If auto-setup is selected on a TV the channels always start scanning from Ch21 upwards, but though once channels are stored on the and you wish to carry out a signal check on the channel you are viewing, if you go into the DVB tuning menu / signal condition its only then that the mux channel number associated with the programme number your are viewing will instantly be seen.
But though, even if you do not have any channels stored you can still check the signal strength of a particular channel and its maybe best if you try things this way, so press: menu - set up - DVB tuning - manual tuning - and you will see a screen bar indicating a channel number on the right hand side, using the up / down facility via the large round button on the remote control inch the channels up or down "one at a time" until you get to either 54 or 61 when if your TV / aerial is OK the signal strength / quality indication of that particular mux channel should immediately appear and which are ITV1 & BBC1 from Mendip, and giving an update on what's seen.
Matter of fact, it would not do any harm if you went though all five multiplexes (HD n/a on that model) from Mendip one at a time using this procedure, (61 - 54 - 48 - 56 - 52) and likewise making a note of the "pseudo" percentages seen, pseudo as they aren't actually marked as percentages as such but just positions along the bar and so an element of judgment will be necessary, but much more importantly note what colour is seen on the quality bar as it should really be green, although touching on yellow now and again is permissible.
I would like to emphasise that everything I am asking you to check is based on you having reported a high level of signal on the Humax, and as aforementioned in a previous posting that if you use the same aerial lead in the Panasonic it should also produce a picture, but if you do not see anything indicated on either 54 or 61 using the manual test then leave the TV sitting on the manual test screen on either channel and pull out the aerial connection, then replace this with a short length of wire of about 18" minimum pushed into the aerial socket and note if this results in anything being indicated, because if not then that points to a fault on the TV.
By the way I haven't forgotten about your Sony box but this test has to be carried out first, as the only other way you can verify if the TV is OK or not is by trying it out on someone else's aerial system.
| link to this comment |
J
jb388:40 PM
Bristol
Chris.SE: Well I didnt actually see / read your posting as I access the site via the twitter link which has been down since the 5th and likewise do not instantly see the lists of latest postings, and have asked Brian(tist) if he could check this out as the same thing had happened about a month ago.
With regards to Charles Stuarts HD signal strength I wasn't actually suggesting that it was too strong, but only acknowledging his report of a strong signal being indicated on his DVD device and informing him of the easy way for anyone to know if their HD problem was being caused by an excessive level of signal.
I do realise that you managed to work out the approximate post code via the coordinates obtained from the terrain predictor, but its a somewhat long winded process and so its much to explain the correct procedure to use when entering a post code into the site settings.
By the way, I likewise have entered Charles's post code into my details for a check.
| link to this comment |
jb38's: mapJ's Freeview map terrainJ's terrain plot wavesJ's frequency data J's Freeview Detailed Coverage
Friday, 13 July 2012
B
Ben Ward2:21 PM
jb38, the process of switching off the mains power supply to my 4 way splitter has been proving a bit of a task as its all in the attic, and I'm not as young as I was so scrambling around up there is difficult! So I am asking a friends son to help out with tracing exactly what cable system/splitter and so on I have in the attic and will report from that point. Perhaps some issue with the splitter is the cause of my problems? We'll see...
As far as the other things you've suggested, using the same aerial cable that gives me normal 90-100% strength/quality on the Humax, but plugged into the Panasonic, only gives me signal strength of between roughly 10% and 30% at best (though with signal quality of 100% each time) when manually checking channels 61 - 54 - 48 - 56 - 52. So rather than green occasionally flickering into yellow, its red occasionally flickering into yellow. I've not yet had time to try the 18inch length of wire you mentioned; could I not get the same effect by using a different aerial cable from the one I know works? (btw I tried a second cable, and no signal appeared at all.)
Thanks.
| link to this comment |
J
jb389:26 PM
Ben Ward: I fully appreciate the difficulty that you mention if as you say the power supply is only accessible from the loft, but the reason that I suggested this test is because that any device of a signal booster variety (no matter how small) automatically becomes an attenuator if un-powered, and in areas of genuinely high signal strength this can be put to good use as far as this being a useful way of verifying (or not) if an excessive level of signal is applying in an installation, because if reception suddenly improves (signal indications rise) by switching off the booster / splitter then it is. (qualifications always applying)
Everything really hinges on what you have reported regarding the signal strength seen on the Humax as it takes quite a signal to indicate that level on this type of box, and although a Humax is a sensitive device its still capable holding out longer than most other equipment before suffering from overload blocking by an excessively high levels of signal.
The Panasonic on the other hand although being equally as sensitive as the Humax "will" start to suffer from excessively high levels of signal over what the Humax can cope with, and the massive difference in levels seen on the Panasonic's signal check screen when using the ex Humax's aerial can suggest this is indeed applying, and likewise could be causing partial instability in the Panasonic's tuner resulting in totally inaccurate readings, with these (and without exception) always being low
This is about the only thing that can be causing the Panasonic's problems, although if not then the actual TV is defective, this being why the issue of a possible excessive signal has to be verified one way or the other.
| link to this comment |
Sunday, 15 July 2012
T
Tracy Gill6:30 PM
Shepton Mallet
Well still unable to get any of the BBC channels. Husband really annoyed as the Olympics are coming up. People keep on suggesting changing the aerial but he's not keen on paying out for something especially if it ends up not solving the problem. Any suggestions?
| link to this comment |
Tracy's: mapT's Freeview map terrainT's terrain plot wavesT's frequency data T's Freeview Detailed Coverage
Select more comments
Your comment please