menuMENU    UK Free TV logo Freeview

 

 

Click to see updates

Single frequency interference

What to do when several channels are missing, but they are all on the same 'multiplex'

What to do when several channels are missing, but they are all
published on UK Free TV

There are several different type of interference that cause problems. This page deals with the situation where:

There are two main causes of this type of intermitted interference: The current Freeview mulitplexes are shown in this diagram. If all of your missing channels are on a single row, you have "single frequency interference":



Local analogue interference

Local analogue interference is caused by household video devices that you can attach to a television such as:
  • Sky Digibox;
  • Video cassette recorder (VCR);
  • Personal digital video recorder (PVR);
  • Games console;
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?
How do I get a test card with Freeview1
I would like to know if it is possible to receive UK terrestrial Freeview servic2
I have been told I would receive too much singal from my Freeview tansmitter as 3
Can my Freeview box receive more than one BBC and ITV region?4
Is it true that my 87 year old mother is entitled to a FREE upgrade when the ana5
In this section
Official aerial installers guide to the TV spectrum future1
Which free digital TV system will give me the most reliable reception?2
High pressure causing channel loss through "Inversion"3
Digital Region Overlap4
Freeview reception has changed?5
Two frequency interference 6

Comments
Thursday, 20 October 2011
A
andy
1:54 PM
Wokingham

Well doubt its local interferance as the same effect can be seen a varoius locations around the town with many miles between them

link to this comment
andy's 2 posts GB flag
andy's: mapA's Freeview map terrainA's terrain plot wavesA's frequency data A's Freeview Detailed Coverage
M
Mike Dimmick
sentiment_very_satisfiedPlatinum

5:34 PM

andy: The Wokingham area suffers from there being a big difference between the analogue and digital signal levels from Hannington. This is a deliberate restriction on the digital output, to protect the analogue services at the Guildford transmitter, and means you can have completely clear analogue pictures and yet unreliable digital.

This flaw was designed into the plan in 1998 and was never lifted despite much investigation of the actual effects on Guildford reception around 2001/2. It will be lifted for the PSBs at switchover (8 and 22 February 2012) and for the commercial multiplexes after Guildford switches (4 and 18 April).

You may get better results from the Crystal Palace transmitter, now and after switchover.

I don't have an explanation why it should have got worse recently, unless a new antenna at Guildford has a different radiation pattern from before (causing an increase in interference) - I can't see any other transmitter that's recently switched over which clashes.

link to this comment
Mike Dimmick's 2,486 posts GB flag
Tuesday, 25 October 2011
M
Muppet
10:34 PM

I have an Alba freeview box attached to a Logik TV and an LG TV with inbuilt freeview. They have both stopped working 9All freeview channels disappeared in September. I am in SW6 area
Trying to figure out what to do as not very techie minded and most of these discussions are going over the top of my head: (

link to this comment
Muppet's 1 post GB flag
Wednesday, 26 October 2011
Friday, 28 October 2011
S
steve
2:10 PM
Derby

Since the switchover my BBC channels have been poor and blocky. I can now bring in 2 sets of BBC channels - one tuned to Look North and one to East Midlands today. I'm guessing that is the Belmont transmitter and the Nottingham transmitter as my aerial is pointing in a NE direction. I use a signal amplifier plugged in behind the TV. Without it I only get one set of BBC channels but the picture is very poor. My aerial has 8 vertically aligned director elements. My post code is DE74 2UW. Also, I've got a satellite dish etc on the wall but I've never used it and don't know if it works. Any advice please?

link to this comment
steve's 1 post GB flag
steve's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage
Saturday, 29 October 2011
G
graham jones
10:55 AM
Peterborough

hello
please can you help me. on oct 28th i suddenly have no analogue channels. This means i cannot watch sky on tvs in the house that do not have asky box attached. Is there anything that can be done? postcode pe4 7zf
Thank you


link to this comment
graham jones's 1 post GB flag
graham's: ...
Briantist
sentiment_very_satisfiedOwner

10:59 AM

graham jones: I would follow the instructions on the Freeview reception has changed? | ukfree.tv - independent free digital TV advice page.

link to this comment
Briantist's 38,910 posts GB flag
M
Mark Harriman
1:47 PM

steve: Since Waltham went digital we get the same here in North West Norfolk. It was always annoying to get Belmont's Yorkshire but our Panasonic tv with built in freeview autotunes and has decided Waltham East Midlands is now the stronger clearer signal!
At least that's better than Yorkshire for us but still not ideal.We really want Look East from tacolneston.

A local Tv man says it has happened because Waltham and Belmont are only at fracationally different angles from us. I imagine you are experiencing a similar problem. For regional tv I begin to think Freesat is the answer as I beleive you can tell it a postcode and it will give the appropriate regional progs. I dont now if Briantist agrees???


link to this comment
Mark Harriman's 11 posts GB flag
Briantist
sentiment_very_satisfiedOwner

2:40 PM

Mark Harriman: Please see Digital Region Overlap | ukfree.tv - independent free digital TV advice .

If you have an older (pre-Freeview HD era) box, you can manually tune your frequencies.

Newer ("D Book 7") tuners will present a menu of regions if they detect more than one.

link to this comment
Briantist's 38,910 posts GB flag
Select more comments

Your comment please
Please post a question, answer or commentUK 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.