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.
_______
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
|
|
Tuesday, 9 January 2024
S
Steve Donaldson7:43 PM
Chris.SE: After posting my comment it occurred that it doesn't have to be a nearby base station causing the interference, but a nearby mobile handset or other device communicating with the network base station.
The 700MHz base station could be distant while the device is close. 'Distant' here is to mean at such distance that it doesn't interfere with TV reception. 'Close' is to mean at such close proximity that it may or does interfere with TV reception.
link to this comment |
Wednesday, 10 January 2024
C
Chris.SE5:42 AM
Steve Donaldson:
Interesting thought that perhaps one should keep in mind.
I do think the likelihood of such a situation is probably quite small though, for the following reasons -
1) The handset would have to be connected to a 700MHz mobile service. They are not widespread at present. Three may have the biggest rollout currently, followed by EE and then O2. Vodafone don't have any 700MHz allocation.
2) The handset would have to be within the beamwidth of the aerial or quite close to very poorly screened coax fly/jump leads. Downlead coax is generally better screened and good installations use double screened such as CT100 or similar.
3) Handset Upstream connections are higher up the 700MHz band so as to minimise the possibility of such interference.
link to this comment |
B
Bristol_Rich9:22 PM
Hi all
By means of an update...just for info imaProject Manager and hence no tech knowledge of frequency and things p...I just want my tv to work;)
I've been in touch with RestoreTV again yesterday who have again confirmed masts are in proximity to our address and - according to advice they have provided - in a frequency range that will likely interfere with PSB2' and filters are being sent through for me to install.
I am in BS16 6 located near to the Avon Ring Road and M4. This area has5G coverage along with multiple mobile traffic monitors located on every lamp standard along the Ring Road ...to say the area is congested across the spectrum is an easy assumption to make...
link to this comment |
Thursday, 11 January 2024
C
Chris.SE12:15 AM
Bristol_Rich:
Unfortunately you have given us pretty well zero technical information about your installation other than it's a loft aerial. So advice and suggestions we've given have to be pretty general based on the most obvious possibilities, this being complicated by the transmitter having Planned Engineering at various times throughout the period you've had problems.
I asked (now on page 235) if you have an amp/splitter to feed more than one TV/Box something which can have a significant effect in the presence of interference, but you haven't mentioned if you have. I also suggested trying a manual tune of PSB2 on UHF C34 and also check if any of the TV channels were already in your 800 TV LCNs. (instead of 3,4,5,6 ....etc) and you've not commented on that either.
You mention Restore TV are sending you some filterS (plural) implying you maybe have more than one TV.
BS16 6 is a large area in which reception could be quite variable due to not only changes in local terrain but that between any specific location and the transmitter. Reception predictors do NOT work on partial postcodes, a full postcode is needed nor can one be certain how many mobile masts might be nearby.
There are at least 20 mobile masts either within or on the periphery of the area with a number of them near or on the Ring Road or M4 and of course you mention the traffic monitors on the lamp-posts (I've no idea what frequency they use, but I will find out for future reference!).
I hope the filters will resolve your issue and that you'll post back with an update but it's going to be almost impossible to add any further practical advice without further technical information other than your aerial should be pointing somewhere at a general compass bearing of around 196 degrees with its rods (or squashed Xs) horizontal (that's nearly SSW).
Any filter should be fitted BEFORE any amplification, otherwise you will be defeating a large part of the attenuation of interference that the filter will give.
link to this comment |
Saturday, 20 January 2024
B
Bruce2:17 PM
Yeovil
Just for information please. We have been on holiday from the 5/1/24 until today. prior to that my good lady put in a whole range of programmes to be recorded while away. checking my recorder, I find either the programme didn't record, or the pictures are very pixelated. My location BA21 4NW
Was there a problem with Mendip during this time or have I got to look closer to home?
Thanks, Bruce
link to this comment |
Bruce's: mapB's Freeview map terrainB's terrain plot wavesB's frequency data B's Freeview Detailed Coverage
C
Chris.SE3:46 PM
Bruce:
Hello again Bruce. Prior to the 8th January, there had been some "work" going on at Mendip, despite it not being on the list, as a couple of the main multiplexes were either on the Reserve Antenna or Reduced power. Everything seems to be running as normal at present.
However, considering your location and the fact that you have line-of-sight to Mendip I think maybe it's things closer to home, and we need to go through everything bit by bit to check it all out.
Might firstly be an idea to check your recorder is still tuned to Mendip's UHF channels!
Knowing that you've had a few issues on and off in recent times and given info on some of your equipment, I've had a look back at your recent posts to check some information, so now I'll ask a few questions and make some comments.
Have you had a new aerial since February 2018 particularly, or even since 2013?
Is it on the roof or in the loft?
You've not mentioned having any amp/splitter for more than one TV/box so I assume you haven't got one, just as previously mentioned, your various boxes daisy chained.
Signal strength figures you mentioned in some previous posts don't seem what I'd expect, so next questions -
Do you know where to look on your TV for Signal Strength and Quality figures?
Have a look at the coax plug on the end of the cable from the aerial - does it look free of corrosion and is it dry - no water?
Plug it direct into the TV and check the Strength and Quality figures for each of Mendip's UHF channels and post those figures.
Then plug it back to it's normal box with the following daisy chain, then check and post the figures on the TV again.
I think this will do for starters, don't want to get things over complicated at once.
link to this comment |
Tuesday, 23 January 2024
C
Chris.SE7:32 PM
Bruce:
Did you not see the reply? Despite the Planned Engineering (whatever they're doing) the answers to the questions will be helpful.
Transmissions seem down a bit on all mutliplexes except PSB2 and PSB3 at time of posting.
link to this comment |
Wednesday, 21 February 2024
C
Chris.SE11:59 PM
There's not supposed to be any Planned Engineering at Mendip this week or last - well none is listed!!
Yet I've got reduced signal strength again this week and last on PSB1, ArqA, SDN and the Local Mux. There was also a brief interruption to at least PSB2 transmission at circa 9.30pm. so at present it's anyone's guess!
It was normal for a few days back around a week or so ago.
link to this comment |
Monday, 25 March 2024
N
Neil Macey12:35 PM
Is there a reason why channels 3, 4 & 5 have become noticeably pixelated over the last few weekends in BA14? During the week they appear to be more stable and 1 & 2 are unaffected.
link to this comment |
C
Chris.SE2:05 PM
Neil Macey:
The transmitter is currently listed for Planned Engineering and has been for a few weeks with "Possible effect on TV reception week commencing 25/03/2024 Pixelation or flickering on some or all channels".
See information at the top of the page and previous posts (p237).
Signal strengths appear to be normal at the time of posting this.
Do check obvious things like your aerial looking intact and still pointing correctly, and that all accessible coax connections are good with no corrosion or water.
If you are still having problems we'd need a full postcode to check predicted reception and whether you have any aerial amplifier/splitter to feed more than one TV/device.
link to this comment |
Select more comments
Your comment please