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 11/11/2024 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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Sunday, 23 December 2012
S
Stewart3:46 PM
I know that they are in the 700 bracket of freeview channels. It's the tuning channel I need. Most of the TV channels are in the 50s & 60s, where are the radio channels?
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M
Michael4:31 PM
Stewart: The radio channels are carried in the same muxes as TV and data channels (BBC radio in the BBCA mux, others in SDN, ArqA and ArqB muxes) so there's no special radio tuning required. Which radio or TV channels are you missing in the 700s?
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Tuesday, 25 December 2012
K
k.Barrett8:40 PM
Wideband horizontally polarised chimney mounted aerial pointing at Mendip.
My house is SN40NW postcode (Butts Rd, Chiseldon.)
Megalith.com shows line of sight to Mendip obscured (just.)
4 way amp/splitter loft mounted.
Cheap single insulated airgap down cable but despite all the above reception has always been good.
Over the last two weeks freezing every 1 or 2 minutes for 3 or 4 seconds on BBC1 and occassionally BBC2.
I have checked the cables for damage and water ingress.
I have turned off dimmer switches, heating controls and under floor heating - no change but proves no interference from them.
I have bypassed the amp splitter with no improvement.
I have also replaced the chimney mounted aerial with a loft mounted wideband vertically polarised one pointing at Chiseldon repeater. Then repeated all the above tests and no improvement. I know wide band is not ideal for Chiseldon repeater but being less than 200yds and very clear line of sight it shouldn't be a problem should it.
Now Chiseldon and Mendip transmit BBC1 on different channels so is it other local interference or is the repeater just repeating a freezing channel from the main transmitter.
Do I ask neighbours if they are having problems, report to BBC or try something else like a group A aerial pointing at Chiseldon and Diplex the Chimney aerial as there are no problems from that on other channels.
Help please.
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J
jb389:43 PM
k.Barrett: Out of all that you have reported the most significant factor is you having stated that using the Chiseldon relay did not show any improvement either, because the Chiseldon relay receives its programmes from Mendip and this could indicate that the relay is also receiving a corrupted signal, therefore I would not advise altering anything at present before making some local enquiries for purposes of finding out if others are being affected in a similar way to yourself.
By the way, the fact of having a 16 watts transmitter so close to your location "is" very likely to have an effect on your tuner by slightly desensitising it, this happening no matter what channel you are trying to receive although obviously the effect will get worse the closer you get to frequencies used by the Chiseldon transmitters, although by the fact of the two stations not being that terribly far off right angles to each other plus them being on different polarities does help.
Chiseldon: 27 - 24 - 21 (@ 323 degrees)
Mendip: (43 miles @ 243 degrees) 61 - 54 - 58 - 48 - 56 - 52, please note though that channels 54 (ITV) & 58 (HD service) are classed as variable for reception.
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Wednesday, 26 December 2012
K
K.Barrett12:34 PM
JB38: Yes your reply is really confirming my suspicions and I will talk to neighbours. I was rather hoping that XMas day would give a reliable signal and I could perhaps think about local interference but XMas day was no better.
The local transmitter even at "only" 16 watts will have some effect as it can easily be received on my daughters cheap TV and got 48% signal and a good picture from just 15ft of cheap aerial cable that wasn't connected to an aerial or amp.
However,from previous tests and previous reliable signal I don't think it is that relay causing the problem.
In summer with lots of leaves on trees and the slightly obscured signal from Mendip I would expect it to be poor but why in winter and usually worst when we have clear rather than wet and wind days.
Talk to the neighbours it is then.
Although today it has been perfect. Do the transmitter maintainers read these pages and fix things without saying anything? Triple time to fix something on XMas day might help?
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K
K.Barrett12:40 PM
Reason for hoping XMas day would be good was no one working so no industrial electrical noise and no taxi transmissions but then there isn't much near here anyway.
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K
K.Barrett1:00 PM
Odd this morning. Retuned the PVR and it has ignored Chiseldon (I have both aerials diplexed) and it has locked all channels to Mendip showing 68% strength 100% quality.
When tuned yesterday it selected the low frequency MUX (Chiseldon) as the primary ones and put all the duplicates (Mendip) at channel 800 and above.
Today the signal strength is lower AT 68% when it is usually 72% - 75%, picture is rock solid and it has ignored Chiseldon.
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K
K.Barrett4:54 PM
Now 16:50: picture suddenly freezing and breaking up every few seconds. Signal down to 45% and quality fluctuating between 25 and 75%
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K
K.Barrett4:59 PM
Retuned and BBC channels are now from Chiseldon repeater. Picture slightly better but still intermittently freezing. To me this proves that the repeater is receiving and rebroadcasting a poor signal as the Mendip signal is still fluctuating all over the place but, despite freezing, Chiseldon is solid at 72% strength and 100% quality.
This seems to be a repeat of yesterday; OK(ish) through the day but deteriorating in the evening.
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K.Barrett: I think that the far more likely cause is some electrical interference that is present, whether around your aerial, around the receiver or somewhere along the aerial cable.
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