Computer Related > TV picture pixellating and showing noise bars Miscellaneous
Thread Author: bathtub tom Replies: 21

 TV picture pixellating and showing noise bars - bathtub tom
Since the start of the hot weather I've been experiencing this problem, it's particularly bad today. It occurs on standard and HD channels. I get my signal from the Sandy Heath transmitter less than ten miles away and I have line of sight (I can see the red lights up the tower at night).

Could it be weather related, transmitter problems or my end? Any suggestions welcome.
 TV picture pixellating and showing noise bars - VxFan
Have you tried retuning the TV?

Any neighbours experiencing the same problem?
Last edited by: VxFan on Thu 23 Aug 18 at 12:38
 TV picture pixellating and showing noise bars - bathtub tom
I tried re-tuning a couple of weeks ago - no improvement. I think the neighbours all have sky.
 TV picture pixellating and showing noise bars - CGNorwich
You need to re-tune

www.itv.com/news/anglia/2018-07-16/televisions-in-the-west-of-the-anglia-region-will-need-re-tuning/
 TV picture pixellating and showing noise bars - CGNorwich
In that case:


" f you are having TV reception problems after Tuesday 17 July, you are advised to call the Freeview Advice Line free on 0808 100 0288."

If you have re-tuned to no success they will probably suggest a new aerial
 TV picture pixellating and showing noise bars - tyrednemotional
>>
>> If you have re-tuned to no success they will probably suggest a new aerial
>>

They might, though the proper requirement before re-tune would have been a wideband aerial, looking at the channel spread, and if this was already in place, then the recent change should only require a re-tune..
 TV picture pixellating and showing noise bars - tyrednemotional
I suspect the following could take you off on a wild-goose chase, but it certainly could just be relevant.

There is a widespread re-tuning exercise going on in order to clear up some frequencies in the 700mhz range (destined to be auctioned off, I think).

This means that a number of channels/multiplexes have moved/will move on many transmitters, and this would require a retune (either automatic if your TV supports it, or manual if it doesn't).

The latest event for Sandy Heath was 17th July just gone, and moved the multiplexes on COM5, 7 & 8 (covering a mixture of standard and HD channels).

Now, if you haven't retuned, then I would have expected the channels to go missing rather than deteriorate, but it is just possible that the originals have been left there on lower power in the interim, or that you are picking up a low-power signal from a repeater somewhere that just happens to share the original frequency.

The nature of the change is shown (on page 6 under 17th July: Sandy Heath) in the following document.

www.digitaluk.co.uk/__data/assets/pdf_file/0008/93284/700MHz_clearance_Q3_2018_Anglia_V2.pdf
 TV picture pixellating and showing noise bars - Bromptonaut
We're Sandy Heath as well. While we haven't watched much TV since the Tour de France ended I've not been aware of an issue.

Worth checking whether your aerial is still right. The changes of channel at Sandy Heath on 17 July are sufficient to move multiplexes from one aerial group to another.

Less likely to be an issue if you have a wideband aerial but still worth checking.

We used to have problems back in analogue days with co-channel interference from continental stations during periods of warm weather - same direction as Sandy Heath (SE) but much further away. Stopped when we moved from one end of village to other in 1998.
 TV picture pixellating and showing noise bars - Pat
I'm Sandy Heath as well and have had this problem on and off for some time now. Until July a re-tune used to cure it but after the July change that didn't help.

I followed all the advice on the Freeview website and did a hard reset to delete the channels from the memory and then a manual re-tune. This cured it.....for about 10 days.

Now it happens every couple of days.

It's always on BBC and ITV during 2am to 7am but most other channels are fine so I end up watching Sky News for 4 hours which is stable but rubbish.

I miss PMQ's and Hard Talk.

Pat
 TV picture pixellating and showing noise bars - sherlock47
Probably unlikely when looking at all the facts as presented, but worth a punt. If a signal is overloading the input of the TV you can suffer from some bizarre problems on multiple channels. Worth trying to cut down on the input signal. The proper way to do it is to fit in line attenuators, but since you are line of site a coat hanger stuffed in the aerial socket of the TV may be just adequate!
 TV picture pixellating and showing noise bars - devonite
We get this annoying problem, but on just two of our favourite channels, Quest and Blaze. Our dish is over ten years old and is starting to get rusty, I originally thought this may be the problem, but as other channels are unaffected I now think this may be down to a weak signal, something we can do nothing about. Will painting the dish with Hammerite affect the signal to the other channels? or should I just leave it alone?
 TV picture pixellating and showing noise bars - Haywain
A couple of months ago, we were suffering poor reception of Freesat (from satellite dish) - which we knew was caused by tree growth; Freeview on terrestrial was also getting progressively worse - which we had also put down to the tree issue.

The local aerial supremo was called for and he successfully shifted the satellite dish to a different position - splendid! The Freeview signal was trickier to solve and, in the end, it was found that the cables between sockets and t.v.s were not of sufficiently decent quality ....... I was amazed - I thought that cables were cables were cables. Our man replaced the cables, and the t.v.s were fine. I just wonder if the change in tuning/strength of signal may have necessitated the better quality cable.
 TV picture pixellating and showing noise bars - devonite
As an aside (or rather slight thread drift ;-) ) Our favourite radio station is Radio Gold Uk, we can get it on the Tv via freesat, or on our laptops, so why can't we get it on normal radio's when we tune to 90.5?
 TV picture pixellating and showing noise bars - Zero
>> As an aside (or rather slight thread drift ;-) ) Our favourite radio station is
>> Radio Gold Uk, we can get it on the Tv via freesat, or on our
>> laptops, so why can't we get it on normal radio's when we tune to 90.5?

Is it being transmitted in your area on 90.5 FM?
 TV picture pixellating and showing noise bars - tyrednemotional
>>
>> Is it being transmitted in your area on 90.5 FM?
>>
>>

...only if he's in Accra, Ghana.....

www.radiogold905.com/

;-)

(the particular UK station in question doesn't, AFAIK, have an FM presence anywhere).
 TV picture pixellating and showing noise bars - Zero

>> decent quality ....... I was amazed - I thought that cables were cables were cables.
>> Our man replaced the cables, and the t.v.s were fine. I just wonder if the
>> change in tuning/strength of signal may have necessitated the better quality cable.

cables wick water if there is a weak unsealed joint. They have a shelf life
 TV picture pixellating and showing noise bars - No FM2R
I'd guess that the signal is too strong. Ideally you would measure the signañ strength but given that attenuators are pretty cheap I'd just take a punt.
 TV picture pixellating and showing noise bars - bathtub tom
Same as Pat, the problem's more prevalent on BBC and ITV, although I sometimes listen to the radio by freeview and that freezes now and then (BBC).

It could certainly be my aerial as it's over forty years old and may well have been installed when 625 was introduced. Using the menu facility on the telly it shows the signal strength as 100% and the quality also 100%. Attenuation may be the way to go (after I try the coat hanger).
 TV picture pixellating and showing noise bars - No FM2R
It's worth trying the coat hanger, but it might take your signal strength too far the other way.

The fact that it is the BBC pixelating points to it being the signal is too strong. With a signal too weak then the BBC is typically the last one to pixelate.

 TV picture pixellating and showing noise bars - Zero

>> shows the signal strength as 100% and the quality also 100%. Attenuation may be the
>> way to go (after I try the coat hanger).

I'd go with the overloading theory in that case.
 TV picture pixellating and showing noise bars - Stuartli
As you state the aerial is around 40 years old. it will more than likely be a narowband rather than wideband type - on top of that, digital signals are much stronger so the overloaded signal theory could also come into play.

My transmitter is Winter Hill and, since the digital switchover in late 2009, it has also been serving viewers as far south as Staffordshire and across to the far side of North Wales.

However, there have been a number of times recently when re-tuning has been required, usually for new channels or, for example, adding and then removing temporary extra Red Button channels for Wimbledon or other major events.

 TV picture pixellating and showing noise bars - bathtub tom
I did try a variable attenuator, that fixed the five main terrestrial channels, but made the signal too weak for many others.

I finally got round to sorting this problem. There was no way I was going to replace the existing aerial that's on a mast on the gable end wall, as I suspect the fittings are all seized solid after forty-odd years and I didn't fancy climbing a ladder that high.

Years (decades) ago, I fitted an 'H' type VHF aerial in the loft for radio reception. As we now listen to digital radio, I decided to remove that and replace it with a wideband aerial - sixteen quid from Screwfix. Problem solved, no pixellating or noise bars.

Any suggestions as to what I can use an old VHF 'H' aerial for? I thought plant supports.
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