Freeview intermittent interference
Brian Butterworth published on UK Free TV There are several different types of interference that cause problems. This page deals with the situation where:
- Freeview reception is perfect or near-perfect most of the time
- The audio on TV and radio channels mutes momentarily a few times each minute
- The picture on a Freeview channel freezes a few times each minute
There are two main causes of this type of intermittent interference:
- 'Induction' interference
- Mobile phone interference
Induction interference
Induction interference is caused by mains-powered household devices that contain a large motor, such as:- Washing machine;
- Tumble dryer;
- Central heating pump or combination boiler;
- Fridge;
- Freezer;
- Power tools (drills, jigsaws etc)
- Vacuum cleaners;
- Water pumps;
- Automatic doors
You can identify if one or more of these devices is causing the Freeview reception problem by powering off the devices.
If one of these devices is causing the problem, then the reception problem can usually be solved by using a mains filter device and use it on the Freeview boxes mains connection.
Such as device is this: Maplin: 6-Way Flat Screen and HDTV Surge Protector and Mains Filter.
Mobile phone interference
If you keep a mobile phone by your Freeview box or digital television, keep it further away!This also applies to other transmitters such as baby monitors, video senders, walkie talkies, and portable phones.
Help with Freeview, aerials?
Saturday, 18 June 2011
J
Jm F4:11 PM
saltydog: there are several things to conisder / check...
Is the TV (or digibox) faulty? It does happen, even with quality brands, and under guarantee. Easiest check is to substitute a known good digibox and see how that runs.
Is the flylead from the TV (or digibox) to the wallplate OK? A duff lead can behave exactly as you describe.
Is the wallplate OK? I've seen cheap wallplates that use a printed circuit board behind the socket - the solder joints fail making the socket loose and dodgy for signals.
Does the loss of signal occur after rainfall? If so, you may be getting water in the coax cable (which gives high signal loss). Also, on your new aerial, sometimes the lid on the connector housing disappears, and allowing the box to fill with rainwater - does it look to be intact?
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Tuesday, 21 June 2011
N
Nick B.10:39 PM
Solihull
Hi - can you help me - I have been having intremittent problems recieving Freeview channels - pincipally ITV related - as a number of people have reported - it is worse in the evenings. I have upgraded to a large wideband Labgear aerial from Screwfix - still in the loft but reception seems to come and go !?!? Argh
Post code is B90 1HB - pointed at sutton C. Transmitter
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Nick's: mapN's Freeview map terrainN's terrain plot wavesN's frequency data N's Freeview Detailed Coverage
Wednesday, 22 June 2011
P
Penny7:08 PM
Aylesbury
We appear to receive transmission from the Oxford transmitter (looking at the map guide)and using a Freeview box but have Meridian news. For a while now we have had screen freeze and broken speech. This isn't all the time just during parts of the day and sometimes in the evening, at present we switch to analogue when it becomes too frequent. When the channels are not freezing up the pictures are very clear. We are getting the reminders at the bottom of the screen to channel search in Sept. It is appreciated that work is being done on the transmitters leading up to the change over. It seems that people are buying new aerials, TV's etc and still no better off. What problem will it cause if no action were taken until the 'changeover' has occurred? (apart from not being able to get the channels initially). When we channel search now, after the search is completed there is the option to accept or change, we accept incase we lose the channels we already have.(this being the main channels BBC 1,2. ITV3,4,5 plus freeview channels). Will this option not be available after the changeover? (assuming that the aerial won't be fault).
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Penny's: mapP's Freeview map terrainP's terrain plot wavesP's frequency data P's Freeview Detailed Coverage
Friday, 24 June 2011
D
Danny Ivatt9:04 AM
I have a problem with major interference when ever I use my mobile phone in the house either for calling or texting. It doesnt matter where in the house I am it happens and even when I am not using itI think when my neighbour is on theirs it sets it off too. This only does it when I a watching tv through my BT Vision box and does not do it through my normal tv freeview channels. I had the aerial guy out yesterday and checked all signals and reception and said there was not a problem. I have a digital loft aerial installed. Any suggestions please
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J
jb3811:48 AM
Danny Ivatt: I think its really BT you should have consulted rather than the aerial people, as although loft aerials can be more susceptible to picking up interference emanating from sources below where they are mounted, its not generally anything connected with a mobile phone.
I would try a test of switching everything off then pulling out each plug in turn and immediately re-inserting it, this suggested just in case its a bad earth connection on some of the coupling cables.
If this doesn't cure the problem I suspect that there could be a fault on the BT Vision box itself.
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M
Mike Dimmick5:57 PM
Penny: Digital UK's prediction for you is very good across the board, so you really shouldn't be having problems. Some people found that the replacement aerial at the transmitter resulted in *more* signal than they had previously, and therefore had to remove boosters and/or add attenuation.
Oxford gets ITV Meridian news ever since they closed down the short-lived ITV Thames Valley service in 2009.
If it's only Mux 2 that's affected, it could be a cabling issue. If water has got into the cable, the loss in the cable increases, and loss at higher frequencies is greater than at low ones. This can happen if an outside junction box, masthead amplifier, or the connection box on the aerial is not properly sealed, or if the insulation on the cable is damaged, either by rubbing against brickwork or tiles or simply perished due to UV exposure. Cables should be properly secured about every 15cm with cable clips as they travel over tiles and down walls, they should not be able to move.
You could also be suffering from impulse inteference, which is more of a problem in the 64QAM mode used by Mux 2 and Mux A. Check whether the problem occurs when a thermostat or motor switches on, for example central heating pump or hot water heater. If so, get a heating engineer to check the pump. Mobile phones can also cause problems - keep them well away from the TV and cables. Better-quality cables (usually termed 'satellite-grade') are less susceptible to picking up interference.
At switchover, you must do a full reset on both days as the channels are all moving to different frequencies - they replace the analogue transmissions. Analogue channels are completely switched off - it is all digital from now on.
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Thursday, 30 June 2011
P
Penny1:38 PM
Aylesbury
Mike, Many thanks for all suggestions regarding query,all noted as possible cause of problem. TV seems to be a mine field of complexities (I thought computers were complicated). We have now received a leaflet through the post about the change over, giving guide lines on 'what to do' when the time comes. Doesn't cover the amount of detail/info achieved on this website though.
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Penny's: mapP's Freeview map terrainP's terrain plot wavesP's frequency data P's Freeview Detailed Coverage
Friday, 1 July 2011
I
Ian5:16 PM
Eastbourne
Moved to Eastbourne just over a year ago and have been barely able to get an analogue signal let alone a sniff of digital. That was until yesterday (30th June 2011) when to my surprise my weekly scan came up with 24 channels. Ok some appear to be intermittent but one must not complain. Any ideas why I have been suddenly so blessed?
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Ian's: mapI's Freeview map terrainI's terrain plot wavesI's frequency data I's Freeview Detailed Coverage
Tuesday, 5 July 2011
R
Rod11:31 AM
Help! Recently I have periods where the picture freezes for a second and this repeats several times, usually sound is unaffected. May last a few minutes then normal.Not predictable as to when it happens. New HDTV connected to freebox(HUMAX)the latter to roof aerial via wall socket. Aerial shared by other flats - no reported problems from them. Is a mains filter the answer? I would appreciate your comments!
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Thursday, 7 July 2011
R
Rod2:07 PM
Since last post I bought a filter but no change. Not sure aerial is shared with 3 other flats as they have dishes on roof. So is it an aerial problem?
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