Single frequency interference
There are several different type of interference that cause problems. This page deals with the situation where:
- Freeview reception is perfect or near-perfect most of the time
- Several channels are missing, but they are all on the same 'multiplex'
Local analogue interference
Local analogue interference is caused by household video devices that you can attach to a television such as: If you have any of these devices, you will need to work out which of these is blocking the reception of a Freeview multiplex by turning off the suspect device and then rescanning for channels on the Freeview box.If powering off the device restores the Freeview channels from the blocked multiplex, you will need to either stop using the problem device's RF output by disconnecting the RF output cable permanently, or by changing the RF channel number that that device uses. See, for example, How do I change the RF output channel on a Sky Digibox?
You can find a list of the frequencies that are not in use at your location by putting your postcode into the My Freeview reception and looking under the "Free RF channels" section.
Non-wideband aerial in some areas
In some places you will need a wideband aerial to receive all the Freeview multiplexes. For example in Central Birmingham, the Sutton Coldfield has multiplex D on an 'out of group', so you cannot view Film4 or ITV2+1 without an aerial upgrade.To find out if you need an aerial upgrade, see My Freeview reception.
Help with Freeview, aerials?
Friday, 28 September 2012
S
Sarah Bramley12:41 PM
York
Forgot to say, my postcode is YO10 3EY
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Sarah's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage
Sarah Bramley: You may need your aerial replacing if it is a group A one put up in the days of four-channel analogue. See here for an explanation:
Bilsdale (North Yorkshire, England) full-Freeview transmitter | ukfree.tv - 10 years of independent, free digital TV advice
Before you do this, if your receiver has a manual tune facility then use it.
For COM4 multiplex which carries ITV3, 5*, 5USA, QUEST and others, tune to UHF channel 43.
For COM5 multiplex which carries Pick TV, Dave, Really and others tune to UHF channel 46.
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Sunday, 14 October 2012
I
Ian Baty10:48 AM
I am having problems receiving channels on the D3+4 frequency, all other channels are fine. I live in Newcastle Upon Tyne. Is there a problem at the minute or can i do anything to the set to retrive viewing capability of these channels? I have tried a full Auto Scan without any luck already and have a TV with built in Freeview.
Many Thanks Ian.
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Ian Baty: There may be a number of transmitters that can be received from and automatic tuning functions are in no way infallible when faced with multiple transmitters.
Have you confirmed that it is tuned to the D3&4 broadcast from your transmitter?
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Tuesday, 23 October 2012
I
Ian Stewart8:02 PM
Dundee
Why am I unable to get the channels (such as Film on 4) in Dundee from the craigkelly transmitter. When I do get them that are blocky and the sound is just sqeaks. Funnily when I tune into Film4 in the early morning and the teleshopping is on the signal is almost perfect. Also my Sony Bravia shows a "no signal" message whereas other "simpler" tvs in the house get the broken picture described above. We have used the same aerial trained on Craigkelly for about 6 years and it was only sometime in 2011 that we lost Film4, etc., which till then were perfect. Help please.
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Ian's: mapI's Freeview map terrainI's terrain plot wavesI's frequency data I's Freeview Detailed Coverage
Monday, 29 October 2012
A
Anthony4:53 PM
Hi
my postcode is BT221LJ
I have a hd panasonic digital tv.
i have 2 ariels one pointing to divis and one pointing to co louth.
the co louth ariel feed is passed through an vhf uhf inverter bot feeds are the combined in a 21-37 38-68 combining unit and then passed through a 4 output amplifier.
before switchover i had a poor but watchable quality picture from rte
At present I am recieving all digital channels in good quality apart from the rte ones.
I was hoping I could now get these from divis/black mountain rather than having to purchase a saorview box. Any ideas how I might get the rte channels
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Anthony: Your Panasonic TV will probably need to a "Freeview HD" one. HD ready means that it will show HD pictures but doesn't have an in-built Freeview HD tuner. Full HD means that it will show the highest resolution HD pictures and doesn't necessarily mean that it will receive HD signals. Knowledge of the model number would allow us to check the specification.
Manually tune to UHF channel 52. This is the channel used by Clermont Carn, Co. Louth which I assume your RT aerial is directed to. If the manual tune screen has a setting for DVB-T and DVB-T2 modes, then select the former. A Freeview HD receiver will probably be needed to receive Saorview.
If this doesn't work and you decide to attempt reception of the NI Mux, then the "inverter" (diplexer) you identify will have to be removed. This is because the NI Mux broadcasts on C39 which is therefore above the range allowed from your Divis aerial.
I say "attempt" because the Digital UK Postcode Checker doesn't "think" that you are in a good area. These things are never ever perfect and therefore should be taken with a pinch of salt. However, it may be touch and go as to whether it will work (fingers crossed though).
The NI Mux carries only RT One, RT Two and TG4, all in standard definition.
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Wednesday, 31 October 2012
A
Anthony Murray8:54 AM
Hi Dave
my panasonic is model TX-P42C2B
I thought it had a hd tuner
My second digital HD tv at the minute connected to sky is a sony KDL-40V4000
are eithier of them a hd tuner
Many thanks for your help
Anthony
earlier post copied below
earlier
Anthony
Monday 29 October 2012 4:53PM
1 day ago
Hi
my postcode is BT221LJ
I have a hd panasonic digital tv.
i have 2 ariels one pointing to divis and one pointing to co louth.
the co louth ariel feed is passed through an vhf uhf inverter bot feeds are the combined in a 21-37 38-68 combining unit and then passed through a 4 output amplifier.
before switchover i had a poor but watchable quality picture from rte
At present I am recieving all digital channels in good quality apart from the rte ones.
I was hoping I could now get these from divis/black mountain rather than having to purchase a saorview box. Any ideas how I might get the rte channels
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Anthony Murray: It looks as though these two TVs don't have a HD tuner in-built.
I couldn't find the official specifications page on the Panasonic website, but I did come across listings on Play.com and eBay for it and both said that it is "HD Ready". This means that it won't receive HD signals, although I think that some people may have bought such sets prior to HD signals coming on air (i.e. before switchover) with the thinking that they will be "ready" to receive HD when it comes on air.
The specs on the Sony website say that it is "Full HD" rather than "Freeview HD". Full HD means that it will show HD pictures to the highest resolution of 1080p:
http://www.sony.co.uk/pro…#tab
The Sony website also says that the digital tuner supports MPEG2 so it won't show pictures with Saorview (as this uses MPEG4).
Freeview HD receivers are expected to work with Saorview.
Try a manual tune on C52. The TV may tune it but show no picture but will nonetheless indicate if you can receive Saorview.
In order to receive the NI Mux from Black Mountain on C39 you will probably need the diplexer removing (and hence the Clermont Carn aerial disconnected).
Realigning the Clermont Carn on Black Mountain "may" work (this includes retaining the diplexer), although as the diplexer "splits" at C38, adjacent channels are attenuated quite a bit so this could perhaps be doubtful:
Online TV Splitters, Amps & Diplexers sales
In a stronger signal area, this attentuation might not have been such an issue.
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Saturday, 10 November 2012
L
Lesley Gyford4:30 PM
Until last weekend we had very few problems with our freeview. Last weekend all the channels disappeared and I had to retune. since then we have not been able to get the HD channels and the PSB2 Mux keeps coming in and out, often dissappears completely or is so badly pixelated we cannot watch any of the channels. I have a Humax Fox T2 HD box, our aerial is pointing towards the Nottingam transmitter. I have to manually tune otherwise I get interference from Waltham transmitter. This is getting tiresome - does anyone know why this is happening and how I can fix it?
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