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 25/09/2023 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
|
|
Wednesday, 16 June 2021
K
Kelvin Smith1:05 PM
Stonehouse
I live in Stonehouse No7 GL10 3QP and have a new roof top wide band aerial pointing at the Mendip transmitter but have bad signal quality on all the HD channels.
Using my TV signal information I get
Ch Sig Qty BER
32 94 100 0
33 92 76 0
34 92 50 0
35 92 40 1268
36 92 48 0
37 0 0 2,000
48 100 100 0
55 96 0 2,000
I get a slightly better HD pictures if I tune into Wales, but cannot move C5HD & C5HD to 104 & 105;
Ch Sig Quality BER
47 93 70 0
Should I change the aerial to Group B to try and get some more gain in signal strength? Any other thoughts?
| link to this comment |
Kelvin's: mapK's Freeview map terrainK's terrain plot wavesK's frequency data K's Freeview Detailed Coverage
S
StevensOnln11:44 PM
Kelvin Smith: If the figure of 96 for UHF channel 55 indicates a signal strength of 96% then you have a plenty strong enough signal for COM7 already, so fitting a grouped aerial is unlikely to help. BER of 2,000 would suggest that you have a high error rate so you are getting interference from somewhere. Do you have any HDMI cables close to your aerial lead? Poorly screened HDMI leads are a common source of interference and seem to particularly effect UHF channel 55, so try to keep them as separated as possible.
The Freeview detail coverage checker predicts that Ridge Hill would give a stronger signal on all multiplexes, which is the transmitter commonly used in Stonehouse, as Mendip is blocked by the hills in much of the surrounding area, so it may be worth considering realigning your aerial on a bearing of 328 degrees.
| link to this comment |
B
bruce james tearle2:57 PM
following a successful retune of my box earlier in the week, channel 35 [gbnews] was dropping out this morning.
was this weaher relayed?
| link to this comment |
Thursday, 17 June 2021
C
Chris.SE12:24 AM
bruce james tearle:
I think that was a typo there bruce, you meant C36 and yes, one of the predictors was showing quite strong Tropospheric Ducting this morning which will likely have resulted in quite a bit of co-channel interference. This should have subsided now, are your signals back to normal?
| link to this comment |
C
Chris.SE1:20 AM
Kelvin Smith:
As StevensOnln1 says fitting a grouped aerial will not help, especially a B, as you will most likely see a major reduction in Signal for C55 and possibly C32.
As StevensOnln1 has also said, you have adequate signal strength there on all channels - except C37 which is not a Mendip transmission, that's the Local multiplex from Wenvoe and it's also possible you may get sufficient signal from an Oxford multiplex that uses C37 rendering Quality useless.
As has already been mentioned, as you have plenty of signal but low quality - high BER, then interference is the most likely cause. Especially if your aerial and flyleads aren't high quality double screened types, then if you have any HDMI leads near them this can cause interference.
Now there are two other possibilities, interference from other transmitters due to the Tropospheric Ducting that's been around for a few days, but as mentioned to bruce should now be cleared - are your figures any better? You should have 100% quality on all channels - which you should even still have if the signal was lower.
That leads me to the second possibility. Do you have any aerial amplifier/distribution system. If so, it could be you have too much gain. I find it strange that the signal the predictor gives that's likely to be your worst from Mendip (by some margin) is C48, yet your figures show it as the best!
Too much signal/gain will give the sort of numbers you are seeing. Once there is front end overload, the actual strength numbers on the set can decrease, as will the quality. So turn the gain control down and see what figures you then get. The strength figures could go quite low and yet you still get 100% Quality and a very low BER.
If you have no variable gain control, try the aerial direct to your main set and post the numbers.
As for Ridge Hill, although you can get ITV West on a separate multiplex from ITV Central, BBC1 and regional variations are Central, not West, so it'll depend which region you prefer.
| link to this comment |
B
bruce james tearle12:44 PM
Hi
Yes, a definite typo!!
Thanks again for info. All seemed good this morning signal wise, just wish theBroadcaster could get their audio sorted!!
| link to this comment |
Saturday, 26 June 2021
K
Kelvin Smith8:50 AM
Stonehouse
Chris.SE & StevensOnln1: Thanks for your comments regarding quality problems on HD channels on channel 35.
My current set-up is a new wide-band aerial fitted about 2 meters higher than my chimney. The cable goes to the attic where there is an Wolsey LTE WFAV425 powered slitter feeding 3 TV's. It has a variable gain pot and I have tried different settings without any improvement. So did the guy who installed the aerial. At the time channel 35 was so bad the TV's tuned themselves to Wales HD, which was fine (although sometimes had picture breakup), until I re-tuned to get GBNEWS and now they they have gone back to channel 35.
I guess I could re-tune and pull the aerial connector out when it gets to channel 35 and put it back in at channel 36, but that's going to be a bit hit and miss...
All RG6 coax cables are new and of good quality as are the F-connectors.
If I connect my main TV directly to the aerial, I get the following results;
Ch Sig Qty BER
32 30 100 0
33 18 60 0
34 14 50 0
35 no signal
36 10 13 0
37 no signal
48 50 100 0
55 26 100 0
There are no HDMI cables connected on any of the TV's
To me the problem seems more related to weather conditions more than internal interference as sometimes everything works fine. I have turned of my broadband router that is also situated in the attic, just in case... along with everything else I can think of but no improvement...
Turning the aerial to Ridge Hill is an option, but the aerial guy said the signal wasn't any better in that direction. Unfortunately his signal box couldn't measure channel 35! Anyway I prefer HTV West news.
Any other thoughts of what I might try given this additional information??
| link to this comment |
Kelvin's: mapK's Freeview map terrainK's terrain plot wavesK's frequency data K's Freeview Detailed Coverage
C
Chris.SE4:29 PM
Kelvin Smith:
Does your set not have a manual tuning option? If so you can pick the individual channels it tunes to, and I would leave out C37 (unless you are keen to get the Wenvoe local multiplex as you can't get the Local one from Mendip on C30).
Thanks for the figures for the aerial direct to the TV, quite interesting. Not surprisingly you are getting more signal for the higher frequencies as most aerials have more gain at the high end.
This time there's no signal on C35. Considering the figures when the amp/splitter is connected, and comparing it to the other adjacent channels, I say it was likely interference due to Tropospheric ducting.
My guess for the most likely bet is Huntshaw Cross in North Devon it uses C32, C34, & C35 for its COM muxes.
So you might from time to time see issues with PSBs 1 & 2. Don't forget that propagation in such conditions can be very frequency dependant so it won't necessarily affect them all.
Well done for checking possible interference from other sources such as your router.
As for tuning, if you can't manual tune, pulling out the aerial plug at the appropriate time is an option some have used, but as you say it can be hit and miss. Tropo predictions suggest there could be more about in the next few days (even the BBC have a current warning).
Ridge Hill does have a better prediction for you but you'd lose BBC Points West, you can get ITV West on C29 as it has that as well as Midlands on C25.
When conditions are more settled you can see which HD mux, Mendip (C35) or Wenvoe (C47) gives the more stable reception. I doubt there's much more you could do, especially if you can't move the channel LCNs to where you'd want!
| link to this comment |
Sunday, 27 June 2021
Chris.SE: Thanks Chris for your help. I think I'll get the aerial moved to Ridge Hill moved to Ridge Hill and forgo HTV Wetry I'll and see how that works out. Bye bye HTV West...
| link to this comment |
Select more comments
Your comment please