No signal at same time each day

Itineoman

Apologies if this has been answered before ( I tried to search the forum but didn't see anything) and sorry for the long post but I am at a loss.

We have two sky HD+boxes working off a Quad LNB (shop bought replacement after the original died some time ago) We've had the same setup for about sixteen years and the boxes are about nine or ten years old.

One box works as it should but the other started losing signal to first a few, then more, then all TV channels around the same time (4pm) each day, over the course of a few months. The radio channels continue to work fine though.

We don't use the second box all that much so let the issue run on until now. Wimbledon and Love Island on at the same time has focussed my mind on solving the problem though :-)

I replaced the HD box with another spare we had and no difference.

Looking at the system settings, there is good signal strength on input 1 and none on input 2. I swapped the cables just to see if it made a difference.

So far I think I can say:
1. It's not the box as I swapped in another with the same result
2. It can't be the dish alignment as the other box works fine.
3. Is it likely to be the LNB if the channels go off predictably at the same time each day? Anyway the radio channels work so there appears to be a signal, unless video requires an additional channel somewhere?
4. I thought it might be some trees which had grown in recent years but I took them out and that made no difference.

I called Sky Tech support who did the usual checks/resets at their end and then suggested sending someone out to fix it and replace the box at a cost.
What puzzles me is the regularity of the signal loss. Always around 4pm. I haven't waited to see what time it comes back on but it is well into the night I would think.

Has anyone come across this before? I'm inclined to think it is something at the Sky end of things.
The only other relevant thing I can think of is that since we went broadband for the phone the landline connection has disappeared but this has been the case for a long time.

Thanks in advance for any advice.

greasepalm

It could be lnb faulty or water ingress or loose f connector.
Lnbs do fail around 8 odd years as sunlight eventually deuterates them and corrosion

Does this happen on fta channels like BBC 1 etc.

ED E

I don't see water ingress causing a rhythmic failure like that.


https://www.bbc.com/news/uk-wales-54239180

The mystery of why an entire village lost its broadband every morning at 7am was solved when engineers discovered an old television was to blame.

An unnamed householder in Aberhosan, Powys, was unaware the old set would emit a signal which would interfere with the entire village's broadband.

After 18 months engineers began an investigation after a cable replacement programme failed to fix the issue.

The embarrassed householder promised not to use the television again.

The village now has a stable broadband signal.

I'd be looking at interference sources within the home as you're losing 1 of 2 boxes.

Itineoman

ED E wrote: »

I don't see water ingress causing a rhythmic failure like that.


https://www.bbc.com/news/uk-wales-54239180


I'd be looking at interference sources within the home as you're losing 1 of 2 boxes.

Hadn't thought of that. It certainly sounds plausible. I can't imagine any interference from inside the house though, especially one that would follow a daily rythm. We're in a rural village with nothing I know of nearby either. I'll give it a think though, certainly food for thought.

niallb

Itineoman wrote:

... especially one that would follow a daily rythm...

Do you have a water softener?
They usually cycle every 24 hours and a couple of power cuts can often push the cycle time to a different part of the day than you'd expect.

spurious

I am reminded of the old Telecom Eireann excuse...do you live near an electric fence?

Itineoman

niallb wrote: »

Do you have a water softener?
They usually cycle every 24 hours and a couple of power cuts can often push the cycle time to a different part of the day than you'd expect.

Thanks - We've nothing that I can think of on a timer.
I'm thinking the source of interference would be close to the box (inverse square law). It's a long narrow house with the dish at one end, box at the other i.e. 15 m away. The 'good' box is up in the attic half way along with a splitter and magic eye feeding a few different rooms and there is no problem there so that would rule out the busier half of the house as a source.
There's very little in the other half apart from an upstairs office with a few laptops and screens that are there 24/7 so no pattern there either.
Outside there are a few other houses - a pub close enough to pick up their wifi signal so could there be a source there? They may well have a water softener or something similar on a timer. I dunno.

Itineoman

greasepalm wrote: »

It could be lnb faulty or water ingress or loose f connector.
Lnbs do fail around 8 odd years as sunlight eventually deuterates them and corrosion

Does this happen on fta channels like BBC 1 etc.

Hi, First was just a few then more until now all TV channels are gone at 4pm.
Just Radio channels left. I think I changed around the f connectors on the LNB a while back to see if it made a difference as well. LNB is about four years old - predecessor got fried by lightning. You could certainly describe that as electrical interference.:D

Itineoman

Thanks for all the helpful replies - Plenty to think about there. I do appreciate it.

Itineo

The Cush

Itineoman wrote: »

Hi, First was just a few then more until now all TV channels are gone at 4pm.
Just Radio channels left. I think I changed around the f connectors on the LNB a while back to see if it made a difference as well.

So when you swapped the outputs on the LNB the problem remained? In this case I would be looking at the cable/connectors/wall outlet to that TV point. Temperature change thru the day causing the issue in a faulty cable maybe?

If the problem moved when you swapped the outputs the LNB would be my focus.

Itineoman

The Cush wrote: »

So when you swapped the outputs on the LNB the problem remained? In this case I would be looking at the cable/connectors/wall outlet to that TV point. Temperature change thru the day causing the issue in a faulty cable maybe?

If the problem moved when you swapped the outputs the LNB would be my focus.

Sorry if I wasn't clear - I swapped around the inputs on the LNB and it made no difference to either box. The 'good' one worked as normal and the other still had the same issues. So I'd rule out the LNB as a likely source on that basis. The problem has gone on through a few seasons, Summer to Winter to Summer again so I'd doubt anything mechanical/physical/temperature based as the source at this point.

greasepalm

It might be a dodgy cable as you said you only have 1 tuner working. Where do these feeds come from the attic or lnb.
Sat installer should have cable checker and identify which one it is in a bunch of identical ones.

Itineoman

greasepalm wrote: »

It might be a dodgy cable as you said you only have 1 tuner working. Where do these feeds come from the attic or lnb.
Sat installer should have cable checker and identify which one it is in a bunch of identical ones.

'Good' Box is in attic and directly connected to LNB. Splitter sends crappy VHS signal to various rooms. Dodgy one is downstairs and directly connected to LNB independently. I swapped the input cables to the box and it gave the same signal levels on the box i.e. Input 1 remained good and Input 2 nothing.

I expect it will be fine in the morning and will die again tomorrow at 4pm which rules out imho anything intrinsic in the hardware or wiring.
I'll have a look again in the morning - although one faction has robbed the HDMI cable in the meantime to stream Love Island from a laptop on their bedroom TV while Mrs Itineo watched the tennis....:D
Thanks again for the interest and informative replies.

niallb

Have you swapped the box locations yet?
I know you swapped out another box for the 'dodgy one' downstairs,
but I don't think you ever put the dodgy one in the attic.

It's worth doing to see if the problem in your signal might be being caused by the one in the attic even though it's showing up on the one downstairs.
If that swap changes behaviour, it might be worth swapping the spare HD box for the good one.

dxhound2005

People seem to have lost sight of the fact that there is no signal at the same time each day. Could be a "centre of box issue".

https://www.satsig.net/cgi-bin/yabb/YaBB.pl?num=1143468077

Here is an old thread which describes the same problem, and there are a few other similar threads.

https://www.boards.ie/vbulletin/showthread.php?p=60620720

I would be looking at the signal readings, even though you say "good" and "fine". Possibly just a small signal loss turns good into no signal.

niallb

dxhound2005 wrote: »

... Could be a "centre of box issue".... Possibly just a small signal loss turns good into no signal.

That's a great idea to consider.
The issue is obviously something with a consistent period, so a timer or an intrinsic 24 hour behaviour.

OP, was this happening before the clocks moved to Summertime?

If so, (and if you remember!) did it stay at the same wall clock time, change time on the same day or change time on a different day?

Itineoman

niallb wrote: »

Have you swapped the box locations yet?
I know you swapped out another box for the 'dodgy one' downstairs,
but I don't think you ever put the dodgy one in the attic.

It's worth doing to see if the problem in your signal might be being caused by the one in the attic even though it's showing up on the one downstairs.
If that swap changes behaviour, it might be worth swapping the spare HD box for the good one.

Good Idea - I'll try that later on today and will post back.

Itineoman

greasepalm wrote: »

It might be a dodgy cable as you said you only have 1 tuner working. Where do these feeds come from the attic or lnb.
Sat installer should have cable checker and identify which one it is in a bunch of identical ones.

All are coming direct from the LNB. The good box is in the attic and has a splitter. The problem one as a direct cable run, but there is an F connection halfway along. Maybe there's something to look at there.

Itineoman

niallb wrote: »

That's a great idea to consider.
The issue is obviously something with a consistent period, so a timer or an intrinsic 24 hour behaviour.

OP, was this happening before the clocks moved to Summertime?

If so, (and if you remember!) did it stay at the same wall clock time, change time on the same day or change time on a different day?

I'll have to think about that one as we only use the box now and again. I'll try to tie it down for today at least if I can get time.

dxhound2005

If you can, take a look at the signal readings coming up to the time you expect the signal to disappear. It might fade out gradually, or just disappear immediately. I suspect a dish alignment problem which would only manifest itself intermittently because of the "centre of box" issue. Better alignment would make the problem go away.

What size is your dish?

Itineoman

I think I may have cracked it - I hooked up the box again earlier and there was no signal on either input. Went to the other box and had good signal on both suggesting centre of box might not be the problem. As suggested earlier, I had a look at the cable connections at the LNB and signal has returned at full strength on both. The underlying problem may still be there (I'll know later on this afternoon I suppose) but it looks like a new LNB might be the solution.
Thanks for all the suggestions and help - this is a really great forum and a super resource.
Itineo.

The Cush

Itineoman wrote: »

As suggested earlier, I had a look at the cable connections at the LNB and signal has returned at full strength on both. The underlying problem may still be there (I'll know later on this afternoon I suppose) but it looks like a new LNB might be the solution.

Before replacing the LNB can you remake the cable connectors, ensuring centre-core wire and braid aren't in contact when done.

dxhound2005

Itineoman wrote: »

I think I may have cracked it - I hooked up the box again earlier and there was no signal on either input. Went to the other box and had good signal on both suggesting centre of box might not be the problem. As suggested earlier, I had a look at the cable connections at the LNB and signal has returned at full strength on both. The underlying problem may still be there (I'll know later on this afternoon I suppose) but it looks like a new LNB might be the solution.
Thanks for all the suggestions and help - this is a really great forum and a super resource.
Itineo.

Depending on where you are, a good test to check the alignment of your dish is CNN SD on 11082 H. It is a weak transponder, and some people struggle to get that signal. Also CNN HD 11670 H, fairly weak transponder and a HD channel usually needs a bit more signal.

There are hundreds of channels, and you may be looking at the signal from only a few of them? BBC, ITV, Channel 4, and Channel 5 are generally on very strong transponders.

https://www.lyngsat.com/Astra-2E-2F-2G.html

Itineoman

dxhound2005 wrote: »

Depending on where you are, a good test to check the alignment of your dish is CNN SD on 11082 H. It is a weak transponder, and some people struggle to get that signal. Also CNN HD 11670 H, fairly weak transponder and a HD channel usually needs a bit more signal.

There are hundreds of channels, and you may be looking at the signal from only a few of them? BBC, ITV, Channel 4, and Channel 5 are generally on very strong transponders.

https://www.lyngsat.com/Astra-2E-2F-2G.html

Thanks. Will do.

Thinking about it again and looking at the replies above, I think it probably was a centre of box issue which became apparent with the weak signal due to a poor connection? It would explain the time of day issue.

Elvis Hammond

SES site has centre of box info: https://extranet.ses.com/CentreOfBox/

Delta Lima

This is all very interesting about the 'centre of the box' thing. Thanks dx.

So is there a best time of day to align your dish for 28 E, and if so , what is it?
Or maybe that would be a bit pointless as the adjustment needed in small dishes in Ireland must be minuscule ?
And also there are various satellites at the 28 East position.

dxhound2005

Sites like Lyngsat suggest dish sizes for the Europe beam on 28 East of 65 to 85 cm. The UK Ireland beam is 50 to 60. We don't know the dish size in this case. There is a big variation in signal strength between the strongest and weakest transponders.

https://www.lyngsat-maps.com/footprints/Astra-2G-Europe-Ku.html

For practical purposes even a less than perfectly aligned small dish will be fine to watch BBC etc. But a dish could be out of alignment enough to cause this centre of box issue, especially if there are dodgy connectors. Someone would need to observe the signal readings on different transponders and see whether all frequencies disappear.

Delta Lima

Ok I was being lazy earlier , so I looked more closely at the link Elvis supplied.

So it appears the centre of the box time happens twice a day, and varies from date to date.

I chose the data for Astra 2G , as it has the dodgy CNN signal .

From that, I should be getting my ladder out ready for 12:35:07 today, and if I miss that slot, I should also have my head torch ready for 23:15:38 tonight.