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, 24 March 2012
K
karen10:25 PM
Last week or two but particularly bad tonight, the picture goes all blocky and eventually you cant watch it, happens on BBC and ITV, then it can say no signal and has a 5 min count down!
Have tried reinstalling channels, seem to have lost a few, did that they other week as well when it was bad and they disappear but if I reintall again they come back.
I live in a flat/ground floor and have freeview integrated into my television. I am in ware in hertfordshire
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Sunday, 25 March 2012
A
Ali9:09 AM
I live in Margate, and presumably receive signal from the Dover transmitter. Over the last few days I have barely been able to get a reliable signal for any channels expect BBC Four. (Very boring if you want to watch Casualty). From Wednesday until last night I have constantly had to retuned to pick up anything. I am not the only one suffering this problem. I live in Garlinge, but people in Margate and Birchington experiencing this problem too. Is it technical or the fault of this freak fog we've been having? I've never had any problems with Freeview before.
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S
Su Johnston10:18 PM
Dorking
We share an aerial in this apartment block, and up until about 3 weeks ago, we could all receive all free channels perfectly. Now we regularly get breakup of the picture, No Signal messages etc. Even more annoying, it seems to be at the peak 9pm period and after. Suggest - the digital changeover? the high pressure (didn't happen before) - shere badness on someone's part?
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Su's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage
K
karen11:23 PM
Ware
Su Johnston: Hi
Your comments seem to be the same as what is happening with me. I was wondering for a while whether the new neighbour of 2 weeks was the cause, but reading on here... that seems unlikely. Just wondering if it means we have to suffer this until the swich over which for me starts 4th April. Its also strange that some channels are affected more than others, unless someone can explain some technical reason for that
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karen's: mapK's Freeview map terrainK's terrain plot wavesK's frequency data K's Freeview Detailed Coverage
Monday, 26 March 2012
K
KMJ,Derby12:22 AM
karen: If you are receiving from Crystal Palace, after switchover the PSB muxes will use the frequencies vacated by the current analogue services. If you have good analogue reception now you should have good digital reception on those muxes after switchover. The COM muxes however will share frequencies with Rowridge, which could make them more susceptible to reception problems in overlap areas between the two transmitters. You ask why some frequencies are affected more than others by the weather conditions causing the inversion effect. Lets suppose that the conditions are causing signals from, for example, Belmont to travel further than normal into the London area. These signals will only cause problems on the frequencies that are common to both transmitters, which at present are Mux1, Mux2 and MuxB which are low power at CP and high power at Belmont, so these muxes at CP get swamped and give "No signal" The other common frequency is C30, which is at lower power from Belmont competing with high power analogue Channel 4, this would possibly cause slight "grain" on the CP picture. After switchover CP would probably be strong enough in its main service area to drown out the unwanted weaker signal on most occasions.
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J
Jan Clay1:38 PM
Steve: aerial points west and I think we should use the Talconeston transmitter. Spoke to Hughes in Kings Lynn & they have had a massive number of complaints this morning & say all area transmitters have been upgraded, but it should settle down soon. ....
Our area seems to have overlaps though and how do I know which 'region' showing on my Humax relates to th right transmitter? (52.7718,0.5501)
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Jan Clay: If you are receiving from Tacolneston you should select "Anglia".
There are perhaps some clues carried in the answers to these questions:
- What BBC and ITV regions do you normally watch?
- You say that your TV is tuned in correctly. Go to BBC One on the TV and then bring up the signal strength screen. It will say which UHF channel (frequency) it is tuned to. Do the same for ITV1.
If BBC One is on C55 and ITV1 on C59, then the TV is tuned to Tacolneston and you will be watching BBC East and ITV Angia. You need to select "Anglia". Tacolneston is south east from your location and your aerial will be horizontal (elements flat).
If BBC One is on C49 and ITV1 on C46, then the TV is tuned to King's Lynn transmitter which serves a small area. It is located at Sandringham and your aerial will be vertical (elements upwards). You need to select "Anglia" for this transmitter. King's Lynn does not broadcast all services, so you may be missing the Commercial channels, or they may be subject to poor reception.
If BBC One is on C22 and ITV1 on C25, then the TV is tuned to Belmont which is near Louth which is north west from you. You will receive BBC One Yorkshire (Look North from Hull) and ITV Yorkshire. You need to select "E Yorks & Lincs". Your aerial will be horizontal (elements flat).
I think it is unlikely that you will be served by the transmitters that identify themselves as "Cambridgeshire" and "Bedfordshire".
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Tuesday, 27 March 2012
M
Mr T J Coates8:19 AM
My digital TV was OK until the switch over (apart from seasonal slight deterioration on the BBC), but since then all channels have become useless as the intrmittent sound is occuring about twice per second. Stationary parts of picture OK but moving parts (e.g lips) get scattered. I have a cordless phone near by and a security system with a radio link - could they be responsible?
Why has this happened after switch over - I understood there would then be an improvement. I am having tha aerial checked but as I do'nt get a "no signal" message I guess that is not going to help.
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Mr T J Coates: The first thing to confirm is that the TV is tuned to the correct transmitter.
When digital switchover occurs, signals become stronger and consequently carry further, causing areas of overlap. Maybe this is what has happened.
One reason may be that when your TV stores the channels when performing its automatic tuning scan, it goes with the first one of each that it finds. So if a neighbouring transmitter is found first (perhaps previously the signal was too weak to be available at your location), then it goes with that. Your local transmitter may be in the 800s.
Do you have programmes stored in the 800s? Do they appear to be stable?
In order to suggest a workaround, please can you let me know your location, preferably in the form of a post code (or perhaps nearby post code of a shop if you don't want to give yours) ?
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Mr T J Coates: I'll just add that I asked for your location in order to work out what signals that could be picked up by your receiver.
Also, what transmitter does your aerial point to (or what direction is it pointing in)?
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