MISSING CHANNELS

MBISHOP

Having spent three days on trying to get channels back it’s just not working. I’m on a Sony Bravia Tv. I’ve done a full retune/scan of channels but they are still not there. I’ve checked transmitter and it’s fine and all the connections/inputs etc. 

Before they disappeared we had a couple of weeks of broken up picture on The certain Channels that have disappeared too, they would finally break up and say you’re not connected to the internet. ! It’s the 5star, quest channels and a lot more that are missing.  Getting so confused. Anyone got any top tips. I will call You View tomorrow if this doesn’t work. 

John L

Hi mbishop,
Welcome to the forum. Which channels are you currently missing? There are several factors: your aerial signal, transmitter may have engineering work, etc. Can you provide a bit more information. What signal strength/quality readings are you obtaining?Hopefully someone on the forum can help you further. John L

MBISHOP

Thank you John.... 
Missing 12 16 17 19,  20 to 23,  25 to 27,  29 to 32, 34 to 64, 66 to 73 and 75 up to 99, if there is a 99.............. !! Good quality signal strengths... I tested aerial it said good.     So basically missing all of it...  Nothing has happened except wild and windy weather but its always like that here...
Hope someone can shed some light as we are mystified M

John L

Hi mbishop,
Welcome back. If your signal is strong, the problem is either in your setup or with weather interference, if there is no problems with transmitter. Worth also checking cable condition/ connections, often overlooked.  Have you got a spare TV to check for channels? When you do a retune, best tip is to retune unplugging aerial, scan for channels (will find nil - to clear channel memory on TV) replug and do another retune. Worth a try.

Another thought. Do you use an aerial booster amp? If you do, I would test without just to see if you can obtain more channels. The reason why I mention this is because there could be a fault in amp, which may block some channels, if not all channels.  Good luck/ let forum know how you get on. John L

jonesh

MBISHOP said:

Thank you John.... 
Missing 12 16 17 19,  20 to 23,  25 to 27,  29 to 32, 34 to 64, 66 to 73 and 75 up to 99, if there is a 99.............. !! Good quality signal strengths... I tested aerial it said good.     So basically missing all of it...  Nothing has happened except wild and windy weather but its always like that here...
Hope someone can shed some light as we are mystified M

Signal Strength and Signal Quality are different things. It is possible to have a strong signal with poor quality.

What readings do you get on your TV for Signal Strength and Signal Quality?

Lukе

MBISHOP said:

Missing 12 16 17 19,  20 to 23,  25 to 27,  29 to 32, 34 to 64, 66 to 73 and 75 up to 99

Are you receiving 11 OK?

MBISHOP said:

Missing 12 16 17 19,  20 to 23,  25 to 27,  29 to 32, 34 to 64, 66 to 73 and 75 up to 99

As 13 is OK, presumably you are not in Wales?

MBISHOP said:

Good quality signal strengths... I tested aerial it said good.  

Were those reading taken using the Youview box?

The youview box can only give readings on channels tuned into.

If you used the Youview box to check then it is just stating the reception for one of the chanels that you already know that you can receive.  It can't give an opinion on a channel that you are not tuned into.

MBISHOP said:

   So basically missing all of it...

The channels that you list as missing are all from the 3 main commercial frequencies. For many transmitters these are transmitted at less strength than the public sector broadcasting (PSB) frequencies.  If your aerial's capacity is weakened then those channels associated with the commercial frequencies will break up, or go missing, before the public sector broadcasting (PSB) frequencies.

To check if is your aerial, or the leads attached, or their joins, or an amp, or an unusual hardware issue, you could compare your reception with your aerial to reception from nearby homes.

Lockdowns permitting, if you use a communal aerial then first check with the others that use the same aerial that they are not also having the same issue.  After that check with nearby homes whether they are also having issues.

MBISHOP

Thanks... No not in Wales we are on The Wrekin transmittor in Telford.. 
No box its a 13 months old Sony Tv with YOu View in it...
Ah thank you for that clarification signal strength and quality are different things.. I need to check those again then..
Its our own aeriel and its in the loft... I wonder if something up there has nibbled something !!! Heard mice or something a couple of weeks ago... Thank you very much...

Roy

MBISHOP said:

Thank you John.... 
Missing 12 16 17 19,  20 to 23,  25 to 27,  29 to 32, 34 to 64, 66 to 73 and 75 up to 99, if there is a 99.............. !! Good quality signal strengths... I tested aerial it said good.     So basically missing all of it...  Nothing has happened except wild and windy weather but its always like that here...
Hope someone can shed some light as we are mystified M

@MBISHOP

Amplifying @Luke’s  observations above, those are pretty exactly the channels you lose if you tune to a Freeview Lite transmitter instead of a Full one.

You need to consult a local aerial fitter to see if there are multiple reports of this in your local area, or if it is largely isolated to you; maybe your aerial, if the mice have been tap-dancing on it or someone has disturbed it looking for them, has lost its intended alignment, and this needs correcting. And certainly, (s)he will know which Freeview Lite transmitter is likely to be the culprit, and how to avoid it.

@John L has wondered if you have an aerial booster; besides the things he mentions, these can amplify a Freeview Lite transmitter to the point where it is preferred to the intended Full one. And so, apparently paradoxically, reducing the boost level or even adding an attenuator can bring back the lost channels by pushing the Freeview Lite signals down into the mush, and allowing the TV to fasten back onto the Full transmitter signal.

MBISHOP

Thank you Roy.... MAkes sense I think..   On to it today...Your reply is much appreciated  

John L

MBISHOP said:

Thank you Roy.... MAkes sense I think..   On to it today...Your reply is much appreciated  

Hi Mbshop,
Glad Jonesh, Luke & myself also could be of help. We are also Users on the forum.
Hope you solve your problem. If you need more advice, I'm sure someone can help. John L

MBISHOP

So very strangely, all the channels are back !!! What was all that about ?  Thank you all for your help  

Roy

MBISHOP said:

So very strangely, all the channels are back !!! What was all that about ?  Thank you all for your help  

Probably an atmospheric effect. 

In which case, your TV’s grasp of the Full transmitter may be a bit shaky, and the problem could reappear as the weather changes.

So possibly still worth a chat with a local aerial specialist.

PeterS

Hi, I've had loss of channels and interference issues with my Youview box.I checked the signal strength in the boxes menu and it was  high but signal  strength was low on signal quality.
I had a 4G filter sent in the post a couple of years ago for free and put that onto the aerial  retuned it and all 137 channels are now working with lower signal strength but higher quality ratings  now showing in set up menu.
Looks like signal strength  is different to signal quality.

Roy

PeterS said:

Hi, I've had loss of channels and interference issues with my Youview box.I checked the signal strength in the boxes menu and it was  high but signal  strength was low on signal quality.
I had a 4G filter sent in the post a couple of years ago for free and put that onto the aerial  retuned it and all 137 channels are now working with lower signal strength but higher quality ratings  now showing in set up menu.
Looks like signal strength  is different to signal quality.

@PeterS

That’s why there are two separate measures. While low strength and poor quality generally go together, you can get a high strength low quality signal if it is getting distorted.

Something you should look at is whether your HDMI cable(s) and aerial cable(s) are being run in close proximity; the radiation from poorly shielded HDMI cables, especially on HD and UHD signals, can get into poorly shielded RF (aerial) cables and play havoc with the incoming broadcast signal.

So if they are close, separate them; if this improves matters, but perhaps not enough, look at buying better quality, better shielded, HDMI and aerial cables.

Tim C

I had the same issue with a badly shielded ethernet cable so another thing to check.

Lukе

PeterS said:

Hi, I've had loss of channels and interference issues with my Youview box.I checked the signal strength in the boxes menu and it was  high but signal  strength was low on signal quality.
I had a 4G filter sent in the post a couple of years ago for free and put that onto the aerial  retuned it and all 137 channels are now working with lower signal strength but higher quality ratings  now showing in set up menu.
Looks like signal strength  is different to signal quality.

Signal strength can be very different to quality.

In some instances it looks similar. For example if the signal is so low that the receiver cannot interpret the signal.

In some instances the two are opposite! For example if the signal is so strong it can overload the receiver and the quality can drop, or even go down to zero.  Where this happens reducing, or removing, any amplification can help. If there is no amplifier to adjust then it is possible to cheaply buy 'attenuators'  to reduce the overly strong signal if that is the cause of the issue.  For the current TV frequencies using a 4G filter will work similarly to a weak attenuator. 

If you have any remaining quality issues where the strength appears to be fine but the quality is too low then you could try a variable attenuator. Avoid the £2 plastic cased ones and go for one slightly more expensive.

Obviously what Roy stated about HDMI interference is still a possibility.  What could account for the improvement is that when you added the 4g filter you moved the cables sufficiently apart to stop the interference.

jonesh

According to Satcure, around 50% of Freeview problems are caused by a faulty aerial fly-lead.

It makes sense to ensure that the one in use is sound and of decent quality before investigating other possibilities.

Roy

Tim C said:

I had the same issue with a badly shielded ethernet cable so another thing to check.

I run nothing less than Cat 6, and I have Cat 8 tails from the router to the prewired Ethernet in the walls. I don’t know what those are rated at, but I’m getting Gigabit Ethernet at the other end of all of them, And who knows what else is running in the trunking?

But the shielding on Ethernet cables goes up as the Cat rating goes up.