Why do I get poor signal on some channels, but not others?
Question submitted by Alasdair Bampton
“I have a new digital television connected to my old aerial and I’m currently receiving Freeview. This appears to work perfectly for every channel except the BBC ones which are all prone to breaking up or total loss of signal. Why is this?
If my aerial is faulty, why do all the other channels work perfectly? Is it that the BBC signal is weaker and if so why is that? Will a new aerial make a difference? I have been quoted £150.00 for a new aerial but will it make a difference?”
Our Answer
It’s not uncommon for people to experience this problem, and there’s not one easy answer that applies to everyone. The problem is likely to be one of two things, which we’ll handle separately: Lack of signal, or Interference.
Lack of signal
If your Freeview receiver can get some Freeview channels perfectly, but not others, there are a few possible reasons:
Aerial Type:
The Broadcast TV band goes from 21UHF to 68UHF. In the early decades of analogue TV, TV aerial installers would install an aerial that performed best at certain parts of the band. There were 5 groups of aerial – A, B, C, D and E. Type A performed best from 21 to 27, Type B, from 35 to 53, etc. London’s main TV transmitter broadcast at the lower part of the band, so best performance could come from a Type A aerial.
Now that we have Freeview, with more channels, some people will find that some of the channels are outside the part of the band that their aerial is optimised for. Accordingly, channels outside of the aerial’s optimal band will be worse than others. The normal fix for this is to get a “wideband aerial”, which will cover the entire 21 to 68UHF band.
Signal from transmitter:
Freeview signals are broadcast in groups, known as Multiplexes. It’s not uncommon for one or two multiplexes to be broadcast on reduced power. This is particularly common during the 2008-2012 Digital Switchover. You can find out if your local transmitter is operating on low power, or if there is transmitter work ongoing using the BBC Transmitter Information Tool
Your TV set or Freeview box may have an on-screen signal strength meter – You can use this to check whether the signal for the problem channels is lower than for the other channels. The best way to check though, is to use the special signal strength measuring equipment used by TV aerial installers.
The other thing you can do, is to check with neighbours. If they are getting the problem channels without an issue, that helps to confirm whether it’s a problem with the transmission power, or your aerial
Interference
The other possible reason why some of your Freeview channels are suffering from break-up while others aren’t, is interference. Here are some possible causes:
Use of a modulator
If you are using a TV modulator somewhere in this house, this could be causing a problem. Typically, you’ll find a modulator in a video recorder and a Sky box. They are used to convert the output of a piece of equipment so that it can be sent over TV aerial cable. In the case of Sky, these are used to send signals from a Sky box to a second TV set. In the case of a video recorder, these were used to get a signal to a TV without using a SCART cable. A modulator “broadcasts” a signal on one of the UHF channels between 21 and 68, and your TV would tune in to this channel to get a picture.
If you have a modulator in use, it could be that this is on, or close to, the frequency of the channels you’re having a problem with. You may need to turn the modulator off (if not in use), or tune it to a different channel – one that’s not in use.
Local ‘Noise’:
Admittedly, this is less likely, but it’s still a possible cause. Digital TV equipment can be quite sensitive to various forms of interference – from your home’s main electrical wiring, cordless phones, radio signals (CB, taxis, etc), weather and atmospherics, domestic appliances and heating thermostats.
Some types of interference affect different frequencies. What’s known as RF (radio interference) will be worse at some frequencies than others, and there’s a chance that if the interference is worse for one group of channels, it could be something like your Wi-fi transmitter, cordless phone, baby monitor, or a local taxi company, that’s generating radio frequency interference that’s upsetting some, but not all, of your channels.
If you are getting interference, there are various things to try, such as using high quality aerial cable and connectors, keeping aerial leads as short as possible, and making sure your cables are kept away from mains cables and radio transmitters.
Again, finding out whether other people in your area are similarly affected, is a great way of working out whether the problem is a general one, or something specific to your aerial or home setup.
i am different from the above as bbc works fine as does channel 5. but 5* , 5 +1,5 USA,QVC, ITV2+1,ITV3 and about 4 other channels break up but not badley and it seems worse at certain times of the day. the aerial is on the chimney and only supplies 1 tv. i am in norhern ireland and near belfast so the transmitter is either Divis or Black Mountain. i know people closer to Divis who can get all freeview good with set top aerials so surely with a chimney aerial in bt8 i should be ok.
Even though you’re having problems with different channels, the advice on this page still applies. Your Freeview receiver is not getting enough signal
I have a twist on the above problem. I have a smart TV with built in Freeview. I also have an antenna enhancer plugged in on the other side of the room – without this there is no signal.
Generally speaking I have great reception but sometimes the picture pixelates and freezes. It hits random channels. One evening i only had about 5 channels working so it sometimes gets quite bad. Sometimes it lasts 3 mins sometimes it last hours. Its driving me mad because i can’t see a pattern. Ramdom channels, random amounts of time, random days. I take it as interference and i don’t think it’s from anything in my house.
Any advice would be great as I am one nerve from throwing my samsung through the window.
Thanks Mike
Michael,
You’re right – it sounds like local interference – it could be anything – taxi, nearby transmitter, noisy thermostat, unshielded motor, bad weather, something blocking the path to the transmitter. It will be more of a problem if you have a weak Freeview signal and need to use a booster.
The advice above under “Local Noise” applies. You need to either a) reduce the source of the interference, or b) try to improve the aerial / cabling / connectors, to shield against the interference.
My neighbour and me share an Ariel and our homes are in as dip rich opposite but up the hill is the dyson site could this berber cascasusding our interference?
could somebody translate this into English?
wow – thanks for your prompt answer – all of a sudden I think its my thermostat that kinda makes sense!
M
I have recently upgraded to a HD freeview box for my caravan (static) ,worked fine for week or so, then i noticed that certain channels would pixelate freeze up or even stop all together, all HD channels work fine. I decided to upgrade the cable , I checked on screen and had good signal strength on the channels i had the problem with, all channels were working great this lasted 3 days then the same channels started freezing again I checked the signal strength and it had gone right down to nearly zero,
Any advice would be appreciated
Thanks Jon
OK. Some things to check:
1. Is there good Freeview coverage in your area?
2. Are other people in the area affected?
3. Has the Switchover happened in your area?
4. Is your TV aerial suitable?
5. Is there anything that could be blocking your signal, or causing interference?
6. What have you tried so far?
i have just purchased a hitachi built in freeview tv and im having problems with some off the channels i get interference on some channels what can i do to stop this from happening
THIS WORKED FOR ME – PROBABLY YOUR MOBILE PHONE
I had the same issue. All BBC transponder signals froze the TV. It was intermittent, but usually occurred within a very short time. Resetting/Re-Tuning did not cure it. The only way to access the TV’s functions again was to power off and on.
I initially assumed it was too much signal, but it was not that either.
It was as if something was causing the TV to have an internal mental breakdown but only on the BBC transponder channels.
I was about to give up, and send the TV to the tip, when I found the solution by chance.
I had started to use a TV card in my PC, because of the problem, but there were often occasional wavy lines, and buzzing on the sound. I knew from experience this was due to a mobile phone doing its periodic background ‘check in’, and of course when it was transmitting during a conversation.
So I bought a TV aerial filter designed to limit mobile phone frequencies, and fitted it between the aerial and the aerial amplifier I use to distribute the TV signal, including the feed to the ‘poorly TV’.
These filters are described as being designed to limit 4G interference, but they actually limit 3G frequencies as well.
THAT WAS IT.
The TV started working with no problems.
I checked several times. Remove the filter, and the problem returned immediately. Connect it, cured.
So, strange as it sounds, some Digital TV’s must have a control chip that reacts to 3G and 4G nearby interference, which causes that one frequency band to ‘freeze’ the normal operation when the mobile transmits. As you may be aware a mobile phone transmits in the background often, not just when you are making a call.
A VERY peculiar, and almost insolvable problem with a very EASY cure.
There is a distinct possibility that fitting a filter may cure a lot of problems people are experiencing with the BBC channels, not just the one above. Fitting could not be simpler, TV aerial plug at one end, a socket for your present aerial cable on the other. The filter requires no power. For the best result, fit the filter directly to the TV’s aerial input socket.
TV has worked great with very good reception on all channels for years, however a few weeks ago many channels began to break up ( sound and vision) and some not there at all. various messages on screen such as “No video”, ” No service” or “bad Service” . Have re tuned a couple of times with no improvement, fitted new cable from TV to Ariel socket all to no avail. My Ariel is on the chimney stack and appears to be fine and is not as far as I can tell dislodged or pointing any different to it always has. TV in bedroom is perfectly OK and does not have this problem and I have tried my lounge TV ( where I am having the problem ) in the bedroom and it works fine there too with service on all channels as it use to in my lounge. I`m at a loss to understand why TV appears to be fine, Ariel appears to be fine in one room ( upstairs ) but not down. — One point worth noting my new neighbor had a satellite dish installed on front of the house ( we are terraced ) and it is in very close proximity ( approx 1.5 mtrs ) to my TV and Ariel cable are running very close to each other als. However this was done over 4/5 months ago and my problem has only started within last couple of weeks ? – Any thoughts please how I can rectify. Thank you.
Hi. Did you find the solution to this? Exactly what is happening to me. Thanks in advance.
I’ve just recently noticed that Cambridge TV is shown on channel 7. I would like to watch it to keep informed about local issues, but the sound quality is absolutely appalling, All the other channels I view are simply fine.
The sound on channel 7 breaks up the spoken word making it intolerable to view.
I’ve got 2 digital tv’s connected to one main digital aerial. One picks up all channels and works perfectly, the other has really bad signal on several channels. The tv’s are never on at the same time. Any ideas?
Possibly. I’ve had terrible reception on BBC channels for over a year and blamed BBC for poor signal strength. Then i picked up a solution from another forum and it may explain your issue. In my attic where the aerial comes in I have a signal amplifier and a ‘splitter box’ – where the one aerial source is routed to different outlets in the house. We only use the one, so I took out the ones we don’t use and stuck the one we do into a different socket in the box. Hey presto – I now appear to have perfect BBC again, even on HD. If you swap your leads in your splitter box you may well find the other TV becomes affected, and you’ll just have to choose which one you watch most. On the other hand if your splitter box has three sockets but you only have two TVs, you MAY be able to eliminate the ‘bad’ socket. Go to your attic, and have a look!
Hi, two months ago we fitted a new aerial fitted along with a splitter? which provides aerial points in different rooms. All was fine till 3 days ago and now we have heavy pixelation on approx half the channels, BBC is fine as are some others. This is the same on the two TV’s we currently have in the house so assuming the problem is the new aerial/splitter or a transmission issue. Where do I start ?, thanks
Bbc okay ltv crackling pictures freezing what do l do
Bbc okay ltv crackling freezing jumping cannot record itv please help
I get good TV coverage, but in the last few days have been getting audio interference from Chanel 5.
Doesn’t distort the sound as such but it’s always there in the background. Whispering away.
No new equipment in house or anywhere else that I can find.
Anybody help ?
Tried retuning all channels but didn’t help.
It is random when you can watch it I was under the impression it was a better way of doing things when in reality it is very poor
Seem to be noticing a ‘low frequency’ sound interference on some channels – sounds like either ‘drumming’ or a faint ‘heartbeat’ like noise in the background. This is most annoying, as i am moderately deaf anf have the sound turned up quite high. Sometimes, this noise gets so persistant that it can cause a headache. I have tried retuning my tv, but it has made no difference regarding the low quality sound.
I just set up a tv in my bedroom, new house, the aerial worked fine prior to me, trust the seller, we have become friends, so certainly no doubt on that. I have auto tuned, removed aerial, auto tuned again, tried again. I have nearly all channels just fine but absolutely no BBC at all. It’s really frustrating!
I have moved house and have an aerial in the attic,recently i have started to get problems with channels,sometime i can watch them no problem,then 2 hours later they break up,pixalate and either poos signal or no service keeps coming u!! I am getting rather fed up with this as up till Christmas we had no problems and nothing has been changed or altered since then!!!!!!!!!! HELP PLEASE
Help please
I have just moved and have a Samsung TV whose aerial cable plugs into a Samsung hdd freeview box with dvd player and hard drive. The aerial plugs into the box brought a device which stops interference from 4g. I did the auto channel search as normal. Viewing programme or recording them via the box is totally pixelated however viewing through the the TV which is connected via an HDMI cable is just fine. Any thoughts on how to sort out he hdd box so I can watch and record again?
Been having the same problem as you since June. Only difference is I have Sony TV and Sony hdd box. Also had G4 filter fitted. Did you find a solution to the problem as no one seems to have a clue here?
I live in a block of flats with a shared aerial. Until 4 days ago my picture on all freeview channels was perfect. Now however all but one channel are constantly breaking up and freezing. The one channel that I can get is the local Norwich community channel.
Nobody in my block of flats has this problem, they get all channels.
This is very odd !!
Hi I am in a new build house, tv aeriel is in the loft, bedroom tv did work ok but now all itv channels all channel 4 channels and all channel 5 channels appear scrambled and cant be watchedat all. All other channels are clear. I have tried re-tuning but nothing seems to work. Any suggestions?
I wonder if anyone can shed any light on this for me. I brought a top floor apartment 8 months ago, which had only one TV aeriel point in my lounge. In September of last year a TV engineer extended the feed coming into my property, added a booster and 2 new feeds so i could also have a TV in both the bedrooms.
I moved into my property 2 weeks ago (4 months after the work was done). However, my two below neighbours are complaining of unable to get some channels… firstly the guy below me a few days ago, and now the lady on the bottom floor.
Whilst my TV engineer insists that this could not be something he has done, as the faults with there signal would have been immediate – I am concerned that the maintenance company of the shared building are going to try and pin this on me!
One theory I have is that the property has been vacant for 18 months, so now adding 3 new TV’s to the loop (as such) has this ‘diluted’ the signal to those below me – in which case surely all they would need is a booster, such as myself? it worth noting that the TV engineer who came out to me noted a very week signal, but i had no TV until 2 weeks ago to test. Also surely they (properties below) would of been having issues since i plugged in the TV’s not 2 weeks later?
If there is anyone who can shed any light on this matter, i would be most appreciative as I now have one elderly neighbour who has been giving me very aggressive phone calls since last night!
Thank you in advance.
Have Samsung smart tv with integrated Freeview. A month ago I lost ITV, Channel 4,film 4,more 4, ITV2, so I re tuned the tv and all was ok. Yesterday I lost the same channels, so re tuned, nothing, have tried 4 times and nothing is working. The tv in my bedroom has all channels working ok.
In the last week I have poor signal strength on 5usa, 5* the picture breaks up an is unwatchable. I live in Ipswich Suffolk.
Why is Freeview recently started scrambling Quest channels
5* and Pick channels have become pixel’d and break up in the Cambridge area this last week, all other channels are fine.
I’ve tried viewing via BT youview box and also directly on Samsung Smart TV with the same result.
Hi
I wonder if anyone can help. In the last few months some of my free view channels on the TV in my kitchen were pixilated. (not everyday) I tried re tuning and sometimes that worked. Then one day I pulled the aerial from the socket and waited a few seconds. When I pushed it back in the picture was fine. Now if ever I get a pixilated picture regardless of which channel I simply remove the aerial from the socket plug it back in and voila it works again. Its a bit annoying but anyone got any ideas for the reason.
On and off for the last week or so – and not for the first time – I’ve had trouble with all BBC channels, TV and radio, breaking up. Sometimes, it’s other channels and the BBC is fine. I just took your advice and pulled out the aerial lead and put it back in, problem solved. Why this intermittent problem should only affect the some channels and not others I don’t know, but thank you so much for the tip, Kevin! :)
The recent heat is affecting my freeview chaanels but only the bbc or bbc related ones the others are fine ,this is made more annoying as they’re the ones I have to pay for !!
Here’s a good one! I run a B & B and have freeview televisions in the rooms. Of late, 3 of the televisions (one on the top floor and two on the first floor) have stopped receiving BBC channels. There has been no change in the set up aerial wise and no new masts installed (this is north Devon – that never happens here) so I’m stumped. Any ideas????
Most of the time, my BBC channels alternate between severe breaking-up and disappearance, and I don’t understand anything that anyone is saying ☹️.
I have a out site ariel, I get some channels prefect and the others are bit scrambled why is that
Hi
I’m having a problem with my free view .
New build property with all cables to rooms buried behind plaster, and all coiled up in loft ready to connect our own Ariel.
When we moved in I found out which cable was servicing the lounge .
Terminated that line and had difficulty getting a picture . Played with Ariel quite a lot ( knowone else had an Ariel to guide which direction I needed to point to) but did manage to get signal but didn’t have full range of channels.
Took me two weeks to admit defeat and get a retired Ariel fitter in to have a look.
My Ariel was pointing in the correct direction which he checked with meter.
He couldn’t understand why we didn’t get full channels.
Eventually he managed to tune in my tv and had a good picture and full channel list.
Don’t think he new what he did to restore my tv to full potential . He charged me a very nominal fee for his time / expertise .
We have a problem now and then in which ITV would pixelate now and then buts it’s not been much of an issue .
Then one night last week I decided to wire up all the other cable in the loft to a splitter . (6 way splitter )
And since then we cannot get a picture other than pixelated on channel ITV. Rest of channels seem ok.
I’m wondering if there’s a break in the cable in loft down to the lounge . All other TVs are working great.
I’ve even wondered if the socket outlet could be faulty so purchased a new one even tho the original one was new only few months ago and just cos it’s new doesn’t meen its working properly.
I’m also wanting a diplexer on mast head so we can use the radio off the Ariel so long as I change the outlet on wall to diplexer .
I feel as tho I know what I should do but I’m stuck… I think the only way to sort this out properly is run a new cable from splitter in loft and drop it down face brick work and in to socket behind my tv. I’m almost certain it’s down To a damaged cable !?
Any advice would be greatfully received .
I have three TVs in my house, the main TV is on its own digital aerial. The other two in bedrooms share a digital aerial. One of the bedroom TVs a Samsung pixelates very badly on all ITV channels, ch4, ch5 and some others. If I swap the two bedroom TVs from one bedroom to the other, the Samsung tv still pixelates badly. The other tv still works fine in both rooms. That to me suggests the tv is at fault. Any suggestions. I can check the signal strength on the Samsung, it is 95 on BBC only 20 on ITV
I know it’s an old thread but the problem still the same, in my case I have Sony channel that constantly freezes, I have installed a digital aerial that cost me £200 two years ago, so far I get very good reception, however when it comes to Sony channel, even on a sunny day I sometimes experiences interferences and freezing to the point where you can’t enjoy watching anything.
ITV occasionally freezes, Channel five rarely freezes, but Sony channel is the worst, it’s just my luck because it happens to be the only channel that actually shows old series, I know Forces TV does but not as much.
All of a sudden my BBC is breaking up all other channels are alright this happened the other day and it said bad signal, my TV downstairs is telling me that it can’t give me the channel as it needs programming in. So last evening all the programs that I recorded on my Humax recorder are not of any use as they are interrupted with lines. I have the Crystal Palace as I like London News not Meriden .
My old TV signal booster died just over a month ago, and I bought a new one.
My handyman swapped it for me and it serves 5 TVs (like the old one) even though it has 6 ports. It was working fine but now, some Freeview channels are not available certain times of the day, like 5USA, Food Channel, Challenge etc for most of the day.
Why is that ? I really miss these channels :-(
I have an intermittent issue with the channels (BBC1 etc) on just one multiplex channel [ch32], sometimes making it unwatchable unfortunately most often in the evening. Other multiple channels [ch33 upwards] appear unaffected, certainly ch34 and upwards.
I have a loft aerial but have eliminated the amplifier distributing the signal to several TVs, a VCR and possible interference from internet powerline adaptors. It affects some TVs more than others, worst is an old (but still good) Panasonic.
Signal STRENGTH is good – 7/10 without the amplifier on the Panasonic, 10/10 with the amplifier.
Signal QUALITY is good most of the time, 10/10 when all is good but oscillates anywhere between 1/10 and 10/10 sporadically when messing up.
My loft aerial points to the Mendip transmitter, as do all the outside aerials in my vicinity. I live on an estate.
I am running out of options that I can influence. Any advice would be very welcome!
P.S. Whilst writing this I started to wonder about what else is more likely in the evenings. Lights and light dimmers came to mind so I might plunge us into darkness the next time we lose TV.
After four weeks of intereference on various channels i.e. Quest, Dave etc. I retuned my Youview box to no avail so called TvAerialCompany. They fitted a new aerial on my roof, allegedly a superior one costing £345.60 inc VAT. but we still got the interference so HE retuned the Youview box. Still interference so he cut the end of the aerial lead that goes into the TV and replaced the end of it with wotever it is that goes on the end and interference went but returned that evening. They’re coming back in the morning hopefully to rectify the problem. Think I’ve been ‘done’!!
This worked for me. An 800Mhz 4G filter .
https://at800.tv/decision-tree/our-online-diagnostic-tool-will-help-you-determine-if-the-interference-you-are-experiencing-is-4g-related/
Every 10 seconds or so my tv picture briefly pixelates over a small part of the screen. The tv is a new, smart tv. It is windy outside, could this be causing the problem?
All channels work on our bedroom tv apart from 5usa which is pixelated with hit and miss sound (like watching a game of Minecraft which is narrated by Norman Collier !) Ally he other sets in the house play all channels fine including 5usa
I could get all freeview channels no problem but now I only get a few without break up. This has happened in the past few weeks. Any idea how this is?
BBC channels present no problem but others break up in the evening starting at about 6pm. This is experienced in two blocks of flats adjacent to each other each with a communal ariel.
Just went out this AM.