Full Freeview on the Mendip (Somerset, England) transmitter
Brian Butterworth first published this on - UK Free TV
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.
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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, 9 August 2014
J
jb388:46 PM
Jon: Thanks for the update on the test, I will say though that Ch58 giving indication of 54% strength on the Humax cannot be classed as a particularly sparkling signal level, suggesting that you might possibly be located in a less than ideal area for reception, as even although Mux Ch33 is radiating at around 28Kw "under" that of Mux Ch58 I would still have expected to see a trace of it being indicated using the test as described. However, taking the above mentioned into account, I have to reiterate on that said with regards to the aerial, insomuch that I very much doubt if changing it to a wideband version will result in a signal level (if any) of a sufficient magnitude to resolve a picture, but of course that is entirely your decision. I would though like if you could carry out one final test, that being to blank out everything stored in the tuner, ensuring all has been deleted by "not" seeing anything in the guide list, once verified go into the tuning menu and select DVB-T2 followed by entering Mux Ch33 and check for any evidence of a signal. My reason for requesting this test is that some devices have a problem picking up DVB-T2 transmissions from two separate Mux transmitter channels, and I just want to verify that yours is not one of them. By the way, should you not have any form of booster on your aerial system? then I am quite sure that your somewhat lack lustre signal level would be significantly improved by the addition of this excellent low cost variable gain SLX brand device sold by Argos, it having proved a boon to many who suffered from low signal level problems. Plug-In 1-Way TV Aerial Signal Booster. | eBay
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Monday, 11 August 2014
M
Mike4:14 PM
jb38 Have had installer call to try and sort Ch 33 problem he separated the two aerials and connected Mendip aerial to head amp but did not get any usable signal showing only 2 bars on quality (until having aerial installed to receive Poole there was a fair signal on Samsung and good one on You View) So reluctantly I have given up effort to obtain Com7. Thanks for all your help and advice.
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Tuesday, 12 August 2014
J
jb3812:10 AM
Mike : Thanks for the update on the situation with regards to the aerial installers findings, this unfortunately somewhat backing up that indicated on DUK's reception predictor of Ch33 not being receivable at your location.
However, on the subject of one of your aerials being used for the reception from the vertically polarised Poole transmitter, and with the other for Mendip which is horizontally polarised, are both aerials of the same grouping? or is the one facing Mendip wideband? the other point I wondered about being, has the diplexer now been removed from the system?
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M
Mike8:58 AM
jb38: The diplexer has been re-connected the aerial used for Mendip is a wideband type
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J
jb3811:42 PM
Mike: Thanks for the info, although "if" the device in question is definitely a diplexer and "not" a combiner, then this device will have the effect of attenuating the signal from one of the aerials as diplexers are designed to combine aerials of different groupings, and of course reception from both the Poole and Mendip transmitters require the "same" group of aerial with the exception of Mendip's COM7.
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Sunday, 17 August 2014
B
Bernard Sullivan4:47 PM
I am in a very poor reception area for the Mendip tx, but it is at least stronger than any other transmitters. I get all the Mux 1, 2 and 3 channels perfectly, but none of the Mux 4,5 and 6 channels. The receiver reports either poor signal or no signal from these channels. The receiver is tuned correctly. Can anyone explain why this might be, and have any suggestions?
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MikeP
8:26 PM
8:26 PM
Bernard Sullivan
The explanation is that the MUxes 1,2 and 3 are transmitted at a higher ERP than the other muxes. So you will receive a stronger signal from the Muxes 1, 2 and 3. If your signal levels for Muxes 4, 5 and 6 are close to the receiver's lower threshhold you are likely to get picture pixelation or break up and potentially signal loss if the received level drops below that threshhold.
Usually, adding a signal amplifier resolves the weak signals but at the expense of the strong signals, as those become too strong!
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Monday, 18 August 2014
J
Jon11:04 PM
Hi jb38,
Thanks for your persistence and suggestions; I have solved the problem, and the answer is very silly. I didn't blank my Humax, I borrowed an HD signal analyser so I could check the whole of my system from the aerial down. I connected the analyser in the loft, and it said 46dBuV on ch33 direct from the aerial, and gave a decent picture of BBC News HD. I wasn't expecting that!
The aerial goes to a 20dB loft amp, then a long downlead, a passive splitter under the ground floor then to an aerial socket in the living room. There was a huge signal loss in the living room, which was due to the socket. At first I thought the socket was faulty, and then I realised what I'd done. My excuse is that the socket is in an awkward position behind a cabinet, but it is a dual outlet socket (TV/FM) and I had put the plug into the FM hole! It passed enough signal for the higher channels to work, but not channel 33. Now I have 80% signal strength on ch49 and 70% on ch33.
I was convinced there was nothing wrong with my system, so it is only because of your prodding that I actually checked it properly.
Thanks for your help,
Jon
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Tuesday, 19 August 2014
J
jb3811:16 PM
Jon: Re: the Ch33 problem. Many thanks for the update on the outcome of your fault finding exercise in an attempt to trace the reason for the problem, I'll bet you gave a sigh of relief when you eventually found it!
Of course, now that the reason is known this explains why Ch58 was only indicating 54% on your Humax, which as you know was something I commented on, although I feel that even the 54% was purely down to your 20dB booster, as otherwise it would have been a lot lower due to the FM sockets filtering / attenuating of signals in excess of 108Mhz, the top side of the FM band.
With regards to your aerial not being wideband, the situation has to be looked at in a similar way to that applying to boosters, insomuch that a signal "has" to there in the first place to be improved on, and although changing an aerial from C/D to a wideband type in order to accommodate a transmitter operating on a lower frequency "will" in most cases give an improvement, (albeit not always as much as might be expected) it will only do so if an signal is being detected in the first place, detected meaning "not" via an auto-tune which activates threshold limits, but either on a proper signal meter or, by using the aforementioned "manual tune" test procedure which is free of such limits, in your case no signal detected on Ch33 being the reason for my reservations about changing the aerial.
Anyway, thanks again for taking the time to update me on the situation, most interesting!
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Sunday, 24 August 2014
R
Richard11:02 AM
Can anybody tell me what the retune is actually for on 3rd Sept on Mendip? I am in Chippenham.
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