Since coming back from my holiday in mid October I've found that a large number of ITV channels are operating at half-power resulting in severe pixellation and digital burps. BBC channels are being received at full signal strength and seem OK.

Any one else experiencing this ?

Seems a bit early to be digital switchover related - this region is not slated to be switched until next year.

Nick

Have you retuned?

I think my receiver does it automatically at start-up.

I'll check it out.

This all started in late October and at that time all the ITV channels seem to be operating at half power.Now the signal strength seems to be varying between half power and full on a dynamic basis.

I suspect that either this is ITV making adjustments to the transmitters in advance of the 2012 switchover (And turning down the power whilst engineers do their stuff) or alternatively this is some new local transmitter going "Over the top" of the ITV signal ( I've had that in the past with local mobile phone repeaters of which there are many.

Seems to happen once every 18 months.

Postscript

I wonder if its work for 4G mobile causing the problem:-

http://www.ukfree.tv/fullstory.php?storyid=1107051834

Postscript 2

Did a full re-tune i.e. turned power off, removed aerial, turned power on, full station scan, found nothing (aerial out), turned power off (Saved tuned stations as zero),power on again and full scan.

Same as before. A large number of ITV channels running at 1/2 power, with expected LOS, pixellation, line loss and audio squeaks.

Postcript 3

I think I've fouind the answer to the poor reception in North London from the CP transmitter:-

http://www.ukfree.tv/txdetail.php?a=TQ339712

See post by JB38.

Looks like the authorities hope we will put up with it until April 2012.

Nick

Nick

Edited 17 December, 201114 yr by Clunkclick

Dreadful. Five days to the holiday and still only a limited number of the lesser ITV channels are viewable.

The advertiser revenue that must be being lost.

You'd think the relevant CEOs would be jumping all over it.

Nick

Welcome to the wonderful world of the digital switchover! London is always so far behind the times.

We went through this pain a couple of years ago as the South West was one of the first areas to go over. I think the idea was to get the problems sorted so that people in the South East wouldn't have too many issues.

It could be a lot worse, though. It could have been the BBC channels which were down.

Rob.

Have you retuned yet Nick?

Have you retuned yet Nick?

Yes.

Yesterday makes the third complete retune (Switch off, aerial out. Switch-on, re-scan. Switch-off, aerial in. Switch-on, re-scan) in the last month. Still the same.

Signal strength on main ITV channels, channels 4 and 5 and assorted other is still only 50% and relatively invariable. It seems that these channels all reside on one multiplexer - Mux 2

All BBC is 100% strength.

Loft aerial (With mast head amplifier) is pointing at Crystal Palace - I understand that ITV is no longer transmitting from Croydon.

As said, I've had trouble before with local mobile phone and taxi services squashing the signal. But when that happens the signal strength of the affected TV channels becomes highly variable according to whether the local station is transmitting or not.

There's some talk on the TV techie forums I posted above of HD transmissions from Sandy Heath in Bedfordshire affecting ITV transmissions from CP or the ITV multiplexer at CP being damaged.

Personally, I think its the switchover in MUX's under the change referred to here and is probably 4G implementation related:-

http://www.dtg.org.uk/industry/dtt_channels.html

Commercial organisations wanting to have 4 G in place and tested early in anticipation of the economic take-off at the end of next year ?

Abissmal.

Nick

Edited 24 December, 201114 yr by Clunkclick

Yes.

Yesterday makes the third complete retune (Switch off, aerial out. Switch-on, re-scan. Switch-off, aerial in. Switch-on, re-scan) in the last month. Still the same.

Signal strength on main ITV channels, channels 4 and 5 and assorted other is still only 50% and relatively invariable. It seems that these channels all reside on one multiplexer - Mux 2

All BBC is 100% strength.

Loft aerial (With mast head amplifier) is pointing at Crystal Palace - I understand that ITV is no longer transmitting from Croydon.

As said, I've had trouble before with local mobile phone and taxi services squashing the signal. But when that happens the signal strength of the affected TV channels becomes highly variable according to whether the local station is transmitting or not.

There's some talk on the TV techie forums I posted above of HD transmissions from Sandy Heath in Bedfordshire affecting ITV transmissions from CP or the ITV multiplexer at CP being damaged.

Personally, I think its the switchover in MUX's under the change referred to here and is probably 4G implementation related:-

http://www.dtg.org.u...t_channels.html

Commercial organisations wanting to have 4 G in place and tested early in anticipation of the economic take-off at the end of next year ?

Abissmal.

Nick

Nick, there are some issues around London I believe. Same as where I live in North Essex (we use the Sudbury transmitter). The main channels are currently ok, but on some tv's (it seems to depend on how good your set is at trapping and locking onto signals, and your precise location) it is bad on the weakest channels again due to network issues that have to be solved. Transmission power is down for the time being. It's been in the newspapers quite a bit and I expect there is some stuff on line again about it. If a very strong signal is the cause, and it could be in spite of your set showing poor signal strength, then you need an attenuator fitted to your aerial socket to lower the signal strength. Ironically, this allows your tv to grasp more of the signal and give a crystal clear picture and sound.

Edited 31 December, 201114 yr by Estate Man

Nick, there are some issues around London I believe. Same as where I live in North Essex (we use the Sudbury transmitter). The main channels are currently ok, but on some tv's (it seems to depend on how good your set is at trapping and locking onto signals, and your precise location) it is bad on the weakest channels again due to network issues that have to be solved. Transmission power is down for the time being. It's been in the newspapers quite a bit and I expect there is some stuff on line again about it. If a very strong signal is the cause, and it could be in spite of your set showing poor signal strength, then you need an attenuator fitted to your aerial socket to lower the signal strength. Ironically, this allows your tv to grasp more of the signal and give a crystal clear picture and sound.

The info in this article leads me to suspect that it may be 4G related (Given that 4G will be taking over the old analogue TV frequencies):-

http://www.bbc.co.uk/news/technology-15223275

It seems that Vodafone may have put a spanner in the mechanism so that the design of the UK implementation won't be decided until the end of this year (i.e. 9 months delay on the original schedule). Given that BBC Freeview Digital is fine and that just one of the MUX's used by commercial channels is affected, I wonder whether the TV digital switchover process is connected with the 4G issue and, as a consequence,has been temporarily halted pending resolution of the issues raised by Vodaphone.

This problem started in October this year. I hope they don't expect Digital Freeview viewers to put up with this until October next year ?

Nick

any new tall buildings nearby?

I wouldn't worry too much.

There's SFA to watch on the TV these days anyway.

If you really must watch the drivel that the TV companies output then try a Mux Magician Digital Wideband Aerial from Amazon or local aerial retailer.

(I was going to put a direct linkage to it but it kept showing my account details! )

I don't need it, I've got two aerials.

1 x 6' long high gain which picks up Meridian from Basingstoke aka Hannington and now 1x 3' high gain for our local transmitter, so we'll have all of our bases covered.