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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Saturday, 14 November 2020
C
Chris.SE8:35 PM
Alan_C:
Sounds like you've been very thorough in the checks that you've done.
In many respects, I'm not surprised that the signal is better through the tiles rather than a wall, even with all the rain today!!
Yes tilting the aerial slightly can improve signals in some circumstances. Did you try any slight rotation as well whilst it is tilted or isn't there enough headroom for that?
Any signal on C55 now?
Getting any side-lobe signal for Stockland Hill without any amplification was probably expecting a bit much. I still say you have a scope for improving things with the amp, but use a variable attenuator between amp and TV (located at the TV end) should enable you to tweak things to get optimum signal without overload.
It'd give you more chance of a reasonably reliable signal for C55 but improve reliability for C35 going by those figures.
You never know, you might even get a Stockland Hill signal!
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C
Chris.SE8:40 PM
Alan_C:
For the sake of clarity, when I said "to tweak things to get optimum signal without overload" it really means to get the Quality figures up, ideally to 100% without overload.
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Wednesday, 2 December 2020
A
Alan_C6:46 PM
Somerton
Chris.SE:
I've obtained an attenuator (-20dB max) and done some more experiments. I connected aerial to amplifier to attenuator to TV and recorded signal quality and level at every whole turn of the attenuator knob - assumed to be a change of about 4dB per turn. Disappointingly, there was no attenuation setting at which the signal quality on Channels 35 and 48 was improved. I also tried it with the connections the other way around: antenna-attenuator-amplifier-TV; the results weren't any better.
I still don't understand why I'm getting poor reception on channels 35 and 48, yet 36 is excellent. I'm fairly sure that the LOS to Mendip transmitter grazes the top of a heavily-wooded hilltop. I think it looks as though I shall have to venture outside and try installing the aerial on the gable end wall, or failing that the chimney.
I suppose there's still one other thing I could try, and that's turning the antenna to point to Stockland Hill (you may remember I looked to see whether there was any signal on the Stockland channels but I did this without turning the aerial, just to see whether it had any sensitivity out of rear lobes!). Or I could knock a hole in the gable end!
By the way, I'm not clear about 55 - is it correct to say that this has now gone for good?
Alan
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Alan_C's: mapA's Freeview map terrainA's terrain plot wavesA's frequency data A's Freeview Detailed Coverage
Friday, 4 December 2020
C
Chris.SE4:32 AM
Alan_C:
Sorry for the delay getting back to you, C55 is very much alive (but not transmitted from Stockland Hill), the suggestion on many transmitter pages on this site that it was going in November is wrong. For the situation as it was back in June see Rebuilding Freeview High Definition from 2019 onwards | free and easy and the updated situation is that the Clearance programme was eventually completed in August. OFCOM have scheduled the auction for sometime in January 2021. The rest of the situation is as previously suggested, until the auction is completed, we won't know if any MNO will have bought the Centre Frequencies (allocated for SDL use), nor will we know what timescale will be involved for such a purchaser to commission such equipment to use the frequencies and so give any 3 month notice as stated in the current multiplex licence.
Going back to previous posts, you said the aerial was a 48 element, was that a typo as the link is actually a 40 element, there doesn't appear to be a similar 48 element. That aside, the aerial spec. shows a pretty flat response across the spectrum, so from an aerial point of view no obvious reason for the C35 and C48 performance, also C36 didn't look that good.
Looking at those figures with the aerial tilted up 15 deg. C48 wasn't bad, it was C35 & C36 that weren't that good, but that was without the amp. So with the amp in circuit and the attenuator at the set end, nothing improved for any setting of the attenuator!! Very disappointing.
Having the attenuator at the aerial end will most likely degrade the S/N ratio a bit but otherwise not much difference.
Give the attenuator at the set end another try. Up until Wednesday evening there'd been some tropo around again which could well have been upsetting the apple cart!
Trees on the LOS can sometimes cause multipath (again, not at all frequencies), but at this time of year I would have expected signals to have been more stable and when the trees are some considerable distance away even less of an effect. So I'm thinking that it's some issue with the position in the loft, I don't known if it's worth tweaking direction a bit, or position back/forth/sideways but keeping the 15 deg. tilt.
PS. If I recall correctly you looked for Stockland Hill pointed at Mendip without the amp?
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Tuesday, 8 December 2020
A
Alan_C9:23 PM
Somerton
Chris.SE:
Hi Chris, thanks for commenting back. I've only got a few notes to add at the moment; it seems I need another session of trial-and-error to see whether there's any way of getting an improvement. Unfortunately I don't think I have enough nerve to go up on the roof, so I'm stuck with trying the loft!
Thanks for clarifying the Ch55 story. It's academic to me at the moment, since I'm not getting anything on that channel, but I shall keep checking it and include it when I make comparisons!
I don't recall describing the aerial I bought as 48 element - it's an XB10K, "12 element" (10 directors, dipole and reflector), X-beam design (but I might have to go up and do a recount).
We've been getting worse reception / more pixellation the last couple of days, even though the weather is now dominated by a weak low pressure system. So I really will have to try changing the position. I guess the small changes I've tried aren't really enough in wavelength terms. Unfortunately it is very hard to find space for it to move - the reflector is right against the rafters as close to the apex as it'll go, so any attempt to move it means I have to position it lower.
I did wonder whether all cable on the market these days is 75 ohm impedance, and hence matched to the antenna (which has a balun)? If not, then maybe I've got a rogue length of 50 ohm or something!
I don't think all the trees have lost their leaves yet.
Best wishes,
Alan
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Alan_C's: mapA's Freeview map terrainA's terrain plot wavesA's frequency data A's Freeview Detailed Coverage
Friday, 11 December 2020
C
Chris.SE2:49 AM
Alan_C:
Hi Alan, I do apologise about the confusion over the aerial, I'd been reading some other performance reports and clearly had the wrong one in mind!
As far as the XB10K tests by ATV go, the gain at C35 & C37 and C48 and C55 (they didn't measure C36 as there was no transmission on C36 at the time the tests were done) was 5dBuV compared to 4dBuV on C32 & C34. It peaks at 8dBuV at C52 & C53, so the results you are getting are a bit of a puzzle if attenuation post amp is not having any effect on the relative Quality and Strength figures.
As far as cable goes, it should have identification marking on its sheath. There is 50ohm cable but it's used in other applications. 75ohm is what should be used as you know.
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Saturday, 9 January 2021
Friday, 5 February 2021
S
Steppy7:25 PM
Can I get Sony Classic (Freeview 51) from the Mendip transmitter?
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S
StevensOnln111:38 PM
Steppy: Sony Classic Movies is carried on the local TV multiplex, which is broadcast from Mendip, but only in the direction of Bristol and some of the surrouding areas.
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Sunday, 14 February 2021
A
Andrew Sparkes 7:57 PM
Is there any issues with channel4 and film 4 signal. Seem to be having signal issues recently. I have rescanned and the aerial has no issues with other channels. Have notice that it seems to be during poor weather that we get the issues
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