Freeview: Mendip (Somerset, England) full-Freeview transmitter
Site settings
For an enhanced Freeview reception
prediction please enter your
full postcode, a national grid reference or
a UK latitude and longitude pair. 
Most popular
On other sites

Freeview on the Mendip (Somerset, England) transmitter

Google StreetviewGoogle mapBing mapGoogle Earth51.237,-2.626 or 51°14'12"N 2°37'33"WBA5 3LB

Transmitter fauls and engineering works

MENDIP transmitter - DAB: BBC National DAB Radio Weak Signal from 11:32 on 15 May to 12:33 on 15 May. BBC
Over the next week Mendip main transmitter: TV (digital) Liable to interruption, no analogue radio, Radio (digital) working normally. Digital tick
Want to better understand the current TV faults? See the all new UK Free TV page


map is loading, please wait...

The symbol shows the location of the Mendip transmitter which serves 720,000 homes.

Other maps:Mendip DABMendip regionBBC WestWest

Radiation patterns

Radiation patterns withheld

Map key

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.

Mendip transmitter Freeview broadcasts

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. The rating shown takes in account the output power level and the various Freeview transmission modes and do not indicate an ongoing fault.

MuxEffective power level, aerial positionRatingModeWatts
PSB1
BBCA
 horizontal
Maximum64QAM 8K 2/3
24.1Mb/s
DVB-T MPEG2		100,000
Channel icons
1 BBC One West, 2 BBC Two England, 7 BBC Three, 9 BBC Four, 70 CBBC Channel, 71 CBeebies, 80 BBC News, 81 BBC Parliament, 301 301, plus 12 others
• as a digital multiplex transmitted on frequency C49 (698.0MHz) from 591m datum.
PSB2
D3+4
 horizontal
Maximum64QAM 8K 2/3
24.1Mb/s
DVB-T MPEG2		100,000
Channel icons
3 ITV (West), 4 Channel 4 South ads, 5 Channel 5 Part Network ads, 6 ITV 2, 13 Channel 4+1 South ads, 14 More 4, 28 E4, 33 ITV +1 (West),
• as a digital multiplex transmitted on frequency C54 (738.0MHz) from 591m datum.
PSB3
BBCB
 horizontal
Maximum256QAM 32KE 2/3
40.2Mb/s
DVB-T2 MPEG4		100,000
Channel icons
101 BBC One HD (England no regional news), 102 BBC Two HD (England), 103 ITV HD (ITV Meridian Southampton), 104 Channel 4 HD South ads, plus 1 others
• as a digital multiplex transmitted on frequency C58 (770.0MHz) from 591m datum.
COM4
SDN
 horizontal
Maximum64QAM 8K 3/4
27.1Mb/s
DVB-T MPEG2		100,000
Channel icons
10 ITV 3, 20 G.O.L.D. (not free), 25 Dave ja vu, 26 Home (not free), 27 ITV 2 +1, 30 5*, 31 5USA, 34 ESPN UK (not free), 38 Quest, 39 The Zone, 44 Channel 5 +1, 72 CITV, plus 22 others
• as a digital multiplex transmitted on frequency C48 (690.0MHz) from 591m datum.
COM5
ArqA
 horizontal
Maximum64QAM 8K 3/4
27.1Mb/s
DVB-T MPEG2		100,000
Channel icons
 TV News,  TV Stars, 11 PICK TV, 12 Dave, 17 Really, 29 E4+1, 32 Movie Mix, 46 Challenge, 48 Food Network, 82 Sky News, 87 Community Channel, plus 9 others
• as a digital multiplex transmitted on frequency C56 (754.0MHz) from 591m datum.
COM6
ArqB
 horizontal
Maximum64QAM 8K 3/4
27.1Mb/s
DVB-T MPEG2		100,000
Channel icons
15 Film 4, 18 4Music, 19 Yesterday, 21 VIVA, 24 ITV 4, 41 Sky Sports 1 (not free), 42 Sky Sports 2 (not free), 47 4seven, 83 Al Jazeera English, 85 RT English , plus 21 others
• as a digital multiplex transmitted on frequency C52 (722.0MHz) from 591m datum.


Regional news from the Mendip transmitter


BBC Points West 0.9m homes 3.4%
from Bristol BS8 2LR, 25km north
to BBC West region - 60 masts.

ITV West Country News (East) 0.9m homes 3.4%
from Bristol BS4 3HG, 23km north
to ITV West region - 61 masts.

Self-help relays

CheddarTransposer15 km E Weston-super-Mare1674 homes
LuccombeActive deflector6 km w Minehead38 homes

How the transmission frequencies change over time

years1984-971997-981998-20102010-1327/3/13-2013-182019-
aerial groupC/D EEEC/D EC/D EWK
C22SDN
C25ArqA
C28ArqB
600C33com7
C35com8
C37C5C5
C40BBCB
C43D3+4
C46BBCA
C48SDNSDNSDN
700C49 BBCABBCA
C51local
C52ArqBArqBArqB
C54C4C4C4D3+4D3+4D3+4
C55+2
C56+CArqAArqAArqA
C58BBC1BBC1BBC1BBCBBBCBBBCB
C59+1
800C61ITVITVITVBBCA
C62+A
C64BBC2BBC2BBC2
C65+B
C67D

orange background for multiplexes names moregreen background for transmission frequencieslilac background for power levels in watts800MHz band: 4G mobile to start in 2013700MHz band: possible 4G in 2019 more600MHz band: new or moved digital TV services more
Notes: + and - denote 166kHz offset; aerial group are shown as A B C/D E K W
Italics for analogue, digital switchover was Wednesdays 24th March and 7th April 2010.

  • Ofcom have projected that a local television service for Bristol could use an Interleaved Frequency on the Mendip transmitter using C51
  • COM7, COM8 projected for 2013-16. COM7 and COM8 to operate as Bristol Ilchester Crescent,Bristol Kings Weston, Mendip SFN.

Comparison of old analogue and current digital signal levels

Analogue 1-4 500kW
Analogue 5(-6dB) 126kW
SDN, ARQA, ARQB, com7, com8, BBCA, D3+4, BBCB(-7dB) 100kW
Mux 1*, Mux 2*, Mux A*, Mux B*, Mux C*, Mux D*(-17dB) 10kW

History of Channel 3 in the Mendip transmitter area

• Breakfast ◊ Weekends ♦ Friday night and weekends † Weekdays only. Mendip was not an original Channel 3 VHF 405-line mast: the historical information shown is the details of the company responsible for the transmitter when it began transmitting Channel 3.


Your comments: most recent posts are at the bottom

firstFirst comments prevEarlier comments  ◊  Later commentsnext Latest commentslast

Your comments are always welcome. Please use the form below to add your thoughts or questions to this page. We will get back to you as soon as we can.

jb38
Friday 13 July 2012 9:26PM
Ben Ward: I fully appreciate the difficulty that you mention if as you say the power supply is only accessible from the loft, but the reason that I suggested this test is because that any device of a signal booster variety (no matter how small) automatically becomes an attenuator if un-powered, and in areas of genuinely high signal strength this can be put to good use as far as this being a useful way of verifying (or not) if an excessive level of signal is applying in an installation, because if reception suddenly improves (signal indications rise) by switching off the booster / splitter then it is. (qualifications always applying)

Everything really hinges on what you have reported regarding the signal strength seen on the Humax as it takes quite a signal to indicate that level on this type of box, and although a Humax is a sensitive device its still capable holding out longer than most other equipment before suffering from overload blocking by an excessively high levels of signal.

The Panasonic on the other hand although being equally as sensitive as the Humax "will" start to suffer from excessively high levels of signal over what the Humax can cope with, and the massive difference in levels seen on the Panasonic's signal check screen when using the ex Humax's aerial can suggest this is indeed applying, and likewise could be causing partial instability in the Panasonic's tuner resulting in totally inaccurate readings, with these (and without exception) always being low

This is about the only thing that can be causing the Panasonic's problems, although if not then the actual TV is defective, this being why the issue of a possible excessive signal has to be verified one way or the other.

Tracy Gill
Sunday 15 July 2012 6:30PM Shepton Mallet
Well still unable to get any of the BBC channels. Husband really annoyed as the Olympics are coming up. People keep on suggesting changing the aerial but he's not keen on paying out for something especially if it ends up not solving the problem. Any suggestions?
jb38
Sunday 15 July 2012 8:59PM
Tracy Gill: I was reading the somewhat lengthy saga concerning your reception problems including "some" of the replies as they likewise can be time consuming to wade through, however what I wondered about was if at any time you had checked with anyone close by to find out if they experience similar reception problems to yourself?

The reason I ask, is because on a Google earth check I see that most aerials seem to be perched on top of high mounting poles, and with the property next to the mini roundabout sign having an aerial that's quite inappropriate for the situation that its in whereby its facing into trees, "inappropriate" by the fact of it being a high gain and likewise sharper pick up device whereas aerials of a much lower gain and likewise having a broader pick up pattern are usually far more effective in these type of situations, and with them not necessary being mounted high up unless by doing so clears the top of the trees, as if it doesn't then the aerial is effectively facing into a higher density parts of the tree vegetation.

Have you at any time purely for test purposes tried a set top aerial to verify or not if anything could be received at lower levels, although the impediment (as I see it) with trying this sort of thing in your type of situation is that the signal would be travelling through the gable end of the property, and so its not exactly a fair test.

Tracy Gill
Thursday 19 July 2012 6:01PM Shepton Mallet
My aerial is mounted on my chimney stack, and my house is the middle one in a terrace. Unfortunately most of my neighbours use Sky. Also I don't know if this could be affecting the signal but a few years ago a load of trees were planted on the side of the hill between us and the mast.
KMJ,Derby
Thursday 19 July 2012 6:37PM
Tracy Gill: Have you ever tried to receive a signal from Stockland Hill? S/H is SW of your location, would that avoid the trees? You would get the wrong regional news, of course, but that would be better than no BBC channels at all.
Tracy Gill
Sunday 22 July 2012 8:10PM Shepton Mallet
Have finally decided enough is enough and have given in to my husband and kids and signed up to sky.
jb38
Sunday 22 July 2012 8:44PM
Tracy Gill: Well satellite reception virtually guarantees glitch free reception for 99.9% of the time 24/7 all the year round as nothing can really affect it, except that is sometimes during a really heavy thundery downpour when the signal might drop out for a minute or so, but though in cases like yours where reception is being spoiled by something out with your control i.e: trees, a satellite system is the only answer whether it be Sky or Freesat.
Owen Lynch
Monday 23 July 2012 8:06PM Trowbridge
Post Code is BA14 6NT

Since early July, my Freeview reception has been poor (Mendip Transmitter) with Pixelation and after retuning, loss of Channels( Sky News / BBC1 / 2 etc). This problems happens regularly during the summer when the trees are in leaf. I fitted a new external aerial last year but still the problems persist. My house has three TVs and all suffer the problem. I also has an 8 Way Aerial Splitter installed (SLX8).
Ben Ward
Monday 23 July 2012 9:31PM
Success! I have sorted out my TV problems FINALLY. It was merely a failed line amplifier which wasn't putting out enough signal (so it was indeed a mains issue). Aerial reception was fine. Thanks go out to Kevin from Wiltshire Aerials.

With a fair few loss of signal/pixellisation problems on the Mendip transmitter reported on here, could some sort of spike have messed people's signal/splitter/amp/picture up?

jb38 especially, thank you for your help with this. I must say I am thankful that I've found this website.
jb38
Monday 23 July 2012 11:50PM
Ben Ward: Many thanks for your update on the situation and pleased to hear that you are fully operational again.

With regards to the powered splitter having failed, this as you will most likely have sussed out was the reason for my request (13th July @ 2.21pm) for you to try switching off the mains supply to the splitter, as if nothing changed by you having taken that action then it was positive proof that the unit was faulty, as of course it transpired that it was, but though I do fully understand your reasons for not being able to carry out the request by fact of its power source actually being in the loft thereby not being easily accessible.

And on the subject of the booster / splitter, if indeed its actual power supply had failed then nothing could really have caused that to happen excepting the possibility of its power transformer having tripped out (thermal fuse) through running continually in a slightly overheated state.

On the other hand though if it wasn't the more usual fault of the power supply having failed and the input to the device was connected to your outdoor aerial, then its likely that its transistorised input amplifier had failed through the aerial having picked up an excessively high level of static rain during some thundery conditions that may have occurred at some time, as boosters / splitters can suffer from this in exactly the same way as do some mast head amplifiers when connected to roof aerials.

Of course this latter comment re: input amp failing is never applicable at any time to loft mounted aerials.
Jeff Glynn
Friday 27 July 2012 7:21AM
As there seems to be spate of aerial distribution amplifiers failing, I would suggest that, if
possible, a passive splitter is tried first. If there is sufficient signal strength, there will my no problems, and nothing to fail. My own setup is configured as follows: aerial to splitter, one side
of which feeds a Panasonic TV, the other side feeding a Panasonic DVD recorder/PVR, the RF output of which feeds a Humax PVR. The signal strength /signal quality bar graph on the
TV and Panasonic PVR shows 100% for both values; the figures on the Humax PVR
shows 79-81% signal strength and 100% for quality.
jb38
Friday 27 July 2012 7:49AM
Jeff Glynn: Yes, passive types might be OK in areas where as you have said, a sufficiently high signal strength exists to be able to use them successfully, but unfortunately that doesn't apply to most areas that suffers from reception problems, plus!! you are using a combination of equipment fitted with top class tuners, as Panasonic and Humax tuners are about the best around, as the types fitted in most other brands are simply not up to their standard in sensitivity nor stability.

Humax of course being about the most accurate for its signal strength readings, whereas Panasonic is inclined to err slightly on the exaggerated side of reality.
Ben Ward
Saturday 28 July 2012 9:48AM
jb38 thanks for the info!
mark
Tuesday 31 July 2012 5:32PM
My tv started freezing last night at 7pm on 30-7-2012 bin ok all day next day to 5pm and started freezing again never had problems befor
Lordgeous
Tuesday 31 July 2012 8:13PM Bath
Ben Ward, seems we had similar problems! Glad Kevin was able to help.
Ben Ward
Tuesday 31 July 2012 10:17PM
Lordgeous, thanks for the contact. Kevin was a big help!
T B Jones
Sunday 12 August 2012 5:11PM
We cannot get Film4 nor ITV3 from Mendip transmitter.
I believe we could get them when digital first available. but not now.
We are also able to receive Wenvoe but that doesnt have these transmissions either
jb38
Sunday 12 August 2012 5:28PM
T B Jones: Its impossible for anyone to be able to offer advice without having knowledge of your location, this in the form of a post code or one from nearby, such as a shop etc.
nige burr
Sunday 9 September 2012 10:14PM Bristol
Hi guys,
we cannot receive any BBC freeview channels at our house. We have 3 different freeview boxes. We have retuned them and still no BBC.
Can anyone tell me if there are problems in my area in Bristol?
How do I get BBC back on the freeview boxes?
Nige
jb38
Monday 10 September 2012 12:22AM
nige burr: Unless you are located in some horrendous localised black spot for reception then as the Kings Weston transmitter is located at only 1.8 miles away from you its possible for you to be receiving an excessively high level of signal dependant on the aerial system being used, as this can completely block reception by overloading the tuner.

If you are using any form of amplifier then for a test try by-passing it, or alternatively use a piece of wire (about 2 or 3 feet) connected into your equipments aerial socket and carry out a "manual" scan on mux Ch43 (Kings Weston BBC1), if though your equipment does not offer a manual scan option then carry out an auto-tune "after" having blanked out anything stored by auto tuning with the aerial removed.

By the way "if" you are receiving from Mendip then the BBC channel is mux Ch61
.
Valerie Sweet
Wednesday 19 September 2012 8:33AM
I have been getting a message today from lunchtime to retune. How do I do this on the Hutton reflector/relay please?
Chris.SE
Sunday 23 September 2012 5:55AM
Valerie Sweet: The easiest way do do this (whatever your transmitter)is a full factory reset using the Freeview reset procedure (there is a link below these posts).
If you are only able to receive the Hutton Relay this should be straight forward. If however you can also pick up Wenvoe and have problems with the Welsh BBC1/2 and ITV1 channels in the wrong locations, you would be best doing a manual tune when you get to step 7. If you are having problems with this, try posting on the Hutton transmitter page.
Chris.SE
Sunday 23 September 2012 6:10AM
nige burr: In your location you should have no problem with reception either from Mendip(aerial rods horizontal pointing South) or from Kings Weston (aerial rods vertical pointing West).
As you say how can you get BBC "back" on your freeview boxes, I assume that you could get them previously. If a full reset using the procedure in the link below does not solve the problem, then you may have some sort of interference (or have altered something in you set up?) so try using the other links below these posts.
Stan
Thursday 4 October 2012 2:55PM
I have a digibox which would always give the Welsh programmes preference. I now know why. With an 'auto scan' I am scanning CH41 & CH44 first and getting an acceptable signal from Wenvoe (as I live between the Mendip & Wenvoe Transmitters). I have at last resolved the issue by doing a manual scan of CH61,CH54,CH48,CH52 & CH56 following a first time install to clear all pre selected channels. My equipment does not support HD so I did not need to instal CH58.
Transmitter engineering
Wednesday 31 October 2012 4:49AM
MENDIP transmitter - Freeview BBC Digital TV Off Air from 01:28 today to 02:47 today [BBC] Over the next week Mendip main transmitter: TV (digital) Liable to interruption, Radio (analogue) working normally, Radio (digital) working normally. [DUK]
Transmitter engineering
Thursday 1 November 2012 4:49AM
MENDIP transmitter - Freeview BBC Digital TV Off Air from 01:28 yesterday to 02:47 yesterday [BBC] Over the next week Mendip main transmitter: TV (digital) Liable to interruption, Radio (analogue) working normally, Radio (digital) working normally. [DUK]
Transmitter engineering
Friday 2 November 2012 7:49AM
MENDIP transmitter - Freeview BBC Digital TV Off Air from 01:28 on 31 Oct to 02:47 on 31 Oct [BBC] Over the next week Mendip main transmitter: TV (digital) Liable to interruption, Radio (analogue) working normally, Radio (digital) working normally. [DUK]
David Rowe
Monday 19 November 2012 2:29PM Westbury
I was experiencing poor reception on BBC Programmes (ecept when on HD Channals. The problem is Auto Setup gets me tuned in to The Wales Transmitter rather than Medip - resulting in Welsh local News etc rather than BBC West. How do I do a Manual Retune ?
Chris.SE
Sunday 25 November 2012 9:37PM
David Rowe: Follow the Freeview reset procedure with the link at the bottom of the page, then do a manual scan, one multiplex ata time using the following UHF channel numbers -
CH61,CH54,CH48,CH52 & CH56 . If you have HD then also C58.
Bob F
Saturday 1 December 2012 3:49PM Stonehouse
I have just seen the following report "Culture Minister Ed Vaizey said an estimated 945,000 households which use signal amplifiers to boost their television reception could be affected, while another 953,000 which rely on communal aerials could have their coverage disturbed".

My post code is GL10 3BJ and I have a signal amplifier and receive Freeview via the Mendip Transmitter.

Should I expect to have a problem. And if so, what would you suggest would be the best solution please?

What is the
Jeff Eastmond
Sunday 2 December 2012 11:02AM Clevedon
On the 'Transmission Frequencies' table above, it does not show what channel the BBCA multiplex is on for the columns headed '2013-' and '2013?' - I hear that in early-2013 BBCA will move from C61 to C49(?) - is this confirmed or subject to change, therefore it's been missed from the table?
KMJ,Derby
Sunday 2 December 2012 12:24PM
Jeff Eastmond: Mux BBCA from Mendip changes to C49 0n 27th March 2013. This is taken from the Digital UK postcode checker site.
Rob
Monday 3 December 2012 5:04PM
Our signal on the BBC PSB1 mux is erratic and I'm not sure why. Some of the time it's OK at about 70% strength, other times it disappears to 'No signal'. However, all other muxes are fine, usually with 100% signal.

We're high up in the Cotswolds near Stroud, and have good line of sight to the Mendip transmitter. It's 40 miles away, but we're 600' ASL and the ground drops away sharply to the south, so there's no obvious problem, and Megalithia shows the signal path is good. We’re in a rural area, so interference is unlikely.

Our aerial is on the same alignment as our neighbours, but is bigger (about 15 elements). It dates from analogue days when it was fine, and I don’t think Mendip changed frequencies in the switchover.

I’ve just left the digibox on manual search for a few minutes. On channel 61 (BBC PSB1 mux from Mendip) it shows a “Signal Quality: Good”, “Signal Level” mostly about 70%, but briefly dipping down to “None” a few times a minute. However, last night we tried to watch a BBC programme, which was OK for 45 minutes (but with very brief interruptions to sound), and then disappeared for the last 15 minutes. Channel 54 is currently showing “Signal Quality: Very Good”, “Signal Level” rock solid on 100%.

All of which leaves me very confused – what problem can give an intermittent fault on one channel and leave the others unaffected. Does the larger aerial mean I should try an attenuator? Any help appreciated.
Stewart
Sunday 23 December 2012 3:41PM
Does anybody know the channel numbers for radio on a freeview from the Mendip traansmitter?
Stewart
Sunday 23 December 2012 3:46PM
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?
Michael
Sunday 23 December 2012 4:31PM
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?
k.Barrett
Tuesday 25 December 2012 8:40PM
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.
jb38
Tuesday 25 December 2012 9:43PM
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.
K.Barrett
Wednesday 26 December 2012 12:34PM
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?
K.Barrett
Wednesday 26 December 2012 12:40PM
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.
K.Barrett
Wednesday 26 December 2012 1:00PM
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.
K.Barrett
Wednesday 26 December 2012 4:54PM
Now 16:50: picture suddenly freezing and breaking up every few seconds. Signal down to 45% and quality fluctuating between 25 and 75%
K.Barrett
Wednesday 26 December 2012 4:59PM
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.
Dave Lindsay
Wednesday 26 December 2012 5:05PM
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.
jb38
Wednesday 26 December 2012 5:39PM
K.Barrett: Well, what you are experiencing is unfortunately not that abnormal in situations such as you have described, and if a signal is always worse on a clear relatively cloud free day then its an indication that the reception at a particular location is dependant on reflective elements, something which certain types of clouds can be rather good at.

All DTT receivers operate on a threshold level whereby the spec of the tuners circuitry determines the minimum level that a signal can be decoded at, and with this level being variable between different brands of equipment, and so if an auto-tune is carried out and the scanning circuitry detects any signals, then even if they are sitting at just a fraction under the threshold level for the particular receiver being used they will either be ignored or maybe placed up in the 800 ranges dependant on how sophisticated the receiver might be.

The other and misleading (for some) aspect of this system being, that if its intended to carry out a manual tune whereby its usual to see the signal strength / quality being indicated as soon as the channel number that's intended to be scanned is entered into the box, this being seen "before" search or scan is pressed, then should it be subsequently discovered that after having pressed same that nothing had been picked up then this is caused by the threshold level circuitry referred to, and is because that as soon as search (or scan) is pressed the threshold circuitry comes into play whereas it wasn't before, as prior to pressing scan etc the tuner was just acting like a "free of restrictions" signal sniffer and why using this facility is a superior way on monitoring signal levels during any alterations being made to the aerial, i.e: by the very fact of continuous indications being seen no matter how low the signal drops to.

Taking this explanation into account you will probably have sussed out why you do not always get the same results during any tuning exercises carried out, i.e: because of you experiencing variable levels of signals from Mendip whereby Chiseldon might take the lead as far as strength is concerned on some occasions.
jb38
Wednesday 26 December 2012 5:52PM
K.Barrett: Just noticed that Dave Lindsay has also replied from another angle, and which if you discover that you are the only person thats having the problem could well apply, the problem possibly caused by either water having entered a junction box or even slight corrosion having developed on one of the connections, although I do appreciate that you have already indicated that you have checked on all of these possibilities.
K.Barrett
Wednesday 26 December 2012 8:57PM
Dave Lindsay / JB38: I don't think it is aerial or corrosion or even local interference especially as my wife and kids remind me that we had very similar problems through certain times in the winter of last year and I had forgotten that. Also why be perfect for 6 hrs today and then give problems from about 17:00?
I guess it could be water ingress but, with exception of connection at roof aerial, I have checked all cables and there isn't any corrosion or water ingress.
Also when connection to the loft aerial facing Chiseldon that is new cable top to bottom.
I have, as above, tried turning on and off all electrical appliances including heating appliances, mobile phones, dimmer switches etc.
Thank you for the current advice but I am now banking on checking with the neighbours unless there are more thoughts.
If I do concede poor aerial connection as a possibility and get an installer in to look at the aerial connection (I am not going onto the actual roof myself - told old for that now) I will upgrade the aerial and get all new double insulated foam down cable.
Dave Lindsay
Wednesday 26 December 2012 9:05PM
K.Barrett: The answer to your question will come should the source of any interference be found. In general, any interference is likely to be when the noisy appliance is switched on and not all appliances are on at all times!

I don't understand your reasoning for thinking that it isn't local interference, especially as you say it happened before which makes me think that it is more likely to be and that whatever is generating it is only used at this time of year.
jb38
Wednesday 26 December 2012 9:33PM
K.Barrett: I really think that you should consider it as priority with regards to making some checks with your neighbours, because unless its known if they are also experiencing the same type of problems as yourself there really isnt any point in you carrying out any further tests more than you have already done, which I may say is seemingly quite comprehensive.


jb38
Wednesday 26 December 2012 9:51PM
K.Barrett: I had also meant to add, that as Chiseldon is located so close to your area of residence then I wouldnt really bother too much about what band of aerial you are using as it doesnt really matter, but though its the fact that you also experience problems with Chiseldon that is the main thing to look into, and along the lines of ensuring that the relay is not just repeating a problem inherited from Mendip.

By the way, although no transmitter engineering should be taking place over the Christmas period faults can still occur on the transmission (relay) side that may not be instantly known about, and so it should not be automatically assumed that the station has a clean bill of health, so to say.
K.Barrett
Wednesday 26 December 2012 10:16PM
Question: if I do consider upgrading the aerial what should I buy? The upgrade path for Mendip as the 800MHZ band is cleared isn't obvious.
Will the powers that be really force those of us in fringe areas through an upgrade path possibly involving multiple aerials, filters and diplexing or will a new aerial be designed that focuses on channels 21 - 59 and not tuned for the 800MHZ range?
K.Barrett
Wednesday 26 December 2012 11:41PM
If, as I expect, my neighbours are experiencing the same problems (Mendip and Chiseldon relay freezing on BBC) who do I report it to?



Please post a question, answer or commentIf you have Freeview reception problems before posting a question your must first do this Freeview reset procedure then see: Freeview reception has changed, Single frequency interference, and Freeview intermittent interference.

If you have no satellite signal, see Sky Digibox says 'No Signal' or 'Technical fault'

If you have other problems, please provide a full (not partial) postcode (or preferably enter it in box at the top right) and indicate where if aerial is on the roof, in the loft or elsewhere.

UK Free TV is here to help people. If you are rude or disrespectful all of your posts will be deleted and you will be banned.







Privacy policy: UK Free Privacy policy.