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DTMark

TV transmitters and channels

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Thought I'd try to get to the bottom of this at last..

TV and PVR box connected to roof antenna.

This is a hilly area. Albeit our house sits a bit higher than most of the others thanks to the way the land "slants".

If you look around, roof antennae are all pointing in different directions - even neighbouring houses can have them pointing the opposite way. I know that around here there's one 'special' transmitter which repeats the signal for the benefit of some in our nearest town. However I think ours points towards Guildford.

Signal has never been great. Particularly, in the summer, some channels just don't work. For weeks or months. However it's not that much of a disaster since they're mostly the crap channels.

I suppose I could fix this by getting a larger antenna fitted, mounted higher up. But we've put up with that as it is. Not bothered enough. This is however being compounded by more problems recently.

For about two years now we've been losing channels. The TV and the PVR box then need retuning.

When you do that the PVR box then "forgets" all the recordings you've set. It's not clever enough to "reconnect it all afterwards". So you have to go and set them all again. Inevitably you then miss things that you've forgotten.

The TV and the PVR box don't necessarily tune identically. By which I mean that sometimes a channel will show on one but not the other. Marginal signal. This has however been getting much worse lately. For example there are days where Channel 4 might work but Channel 4 HD will not. Again the PVR box isn't clever enough to "fall back" to the SD channel.

And now, at precisely a few seconds after 20:40 every evening, while watching The World Cup, the TV signal is completely lost for about 15 seconds.

I know a lot of the frequency changes are to free up spectrum for other uses like 4G and 5G. I'm all for progress. But this is stuff that just used to work but now it's a bit hit-and-miss as to whether you'll be able to watch or record something, or not.

The antenna is still where it was, it hasn't moved at all nor been damaged. I don't suppose these things "wear out". Same TV and box. I don't think anything has changed here.

In summary: it used to be marginal but stable. Now it's marginal and unstable. My instinct is that this has more to do with what's going on at the transmitter end than at this end.

Any idea what's going on here and who I speak to in order to try to "make the TV work properly again"?

 

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I have an antenna amplifier in the loft.

It is the only way that I get a sufficiently strong signal.

I also used to have an amplifier for the mobile phone but got busted by Ofcom who told me that phone ones are illegal.

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I think you're going to need as bigger aerial.... lol.

Do you consider yourself in London or in the Meridian region? The strongest signal for you is the Guldford transmitter which is part of the Crystal Palace network. It would mean that you would get the London TV channels including the London news stories.

If you consider yourself in the Meridian area then you will be wanting to have the TV channels and news from those areas but that means that you aerial will be pointing at transmitters that will be giving you weaker singals.

Deciding which of the above you are currently receiving and which you want to receive affects any decisions that you can make to rectify this.

Currently in the UK there is a lot of transmitter work underway which iscausing interruptioons. Also, the unusual area of high pressure over the country is also affecting TV signals. That yours is disconnecting at the same time each night for a matter of seconds indicates that something is going on at the transmitter relay that you are using.

Decide what channels you want to receive and:

1. You might need to re-point your aerial.

2. You might need a bigger aerial.

3. You might need a booster to boost the signal.

These are the folks who run the transmitters. All the info you need will be here - http://www.digitaluk.co.uk/

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I faffed around like you for ages with Freeview trying to get it right. 

In the end threw it in bin and bought dish and satellite box for Freesat and it is rock solid. 

It's exact same dish as you use for Sky so they are very cheap new or used. You don't need expensive fitting up a wall either, mine was screwed to a post in back garden. As long as it can see direct line of sight to astra satellite everything is good. You also need a box which plugs into TV, these are cheap too. I got my first one from Lidl but wished I spent slightly more and got bit better one. 

Of course all depends on your exact house type and whether you can have a dish but if you can do it then do do it because freeview is a dog unless you live next door to transmitter. 

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The area we live in is some sort of "settled estate" which has certain rules which are enshrined in the tenancy agreement. One of those is 'no satellite dishes'.

Actually a couple of people do have them and have managed to find somewhere to 'hide' them so they're not so ugly as they would otherwise be.

We might be able to get away with it if we can put the dish on the side of the building at the end of the garden below the "fence line" quite low down as long as the coax can handle that length of run. And as long as it can "see" the satellite from there. There aren't any others nearby to get a sense of which way it would have to point. But it's a potential option.

We have London here, not Meridian. But I think the split in the village could well be 50/50 between those two. Neighbouring town can have either, here, you can generally only get one or the other thanks to the topography of the land.

I've never tried moving the antenna around to see if we can get something better but this still doesn't really explain why it is that channels are forever changing frequencies and the things need retuning all the time. Nor why the signal drops altogether on all channels at 20:40 every weeknight. It has been doing that for about a week now. Here's the result set from the DigitalUK website for this area. Guessing we're connecting to #3 in that list.

I'll give a local installer company a call later today - suspect they're very familiar with this "problem area".

 

  Name Region Parent Transmitter Grid Reference Distance (km) Bearing° Aerial Group Now Aerial Group After
Most Likely Transmitter Midhurst Meridian N/A SU 91222 24999 24 141 C/D H,T H B H,K H
Alternative Transmitter Crystal Palace London N/A TQ 33940 71220 64 64 A H,T H A H,T H
Alternative Transmitter Guildford London Crystal Palace SU 97475 48615 22 77 B V,K V B V,K V
Alternative Transmitter Reigate London Crystal Palace TQ 25640 52137 50 80 A V A V
Alternative Transmitter Hannington Meridian N/A SU 52740 56807 27 299 B H,T H B H,T H
Alternative Transmitter The Bournes Meridian Hannington SU 84232 45193 8 81 A V A V
Alternative Transmitter Heathfield Meridian N/A TQ 56680 22074 84 105 B H B H
Alternative Transmitter
  • Crystal Palace (Local Mux)
  •  
London Crystal Palace TQ 33940 71220 64 64 A H A H
Alternative Transmitter
  • Hannington (Local Mux)
  •  
Meridian Hannington SU 52740 56807 27 299 B H,T H B H,T H

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Posted (edited)

Freesat all the way.  So much more, especially as not everywhere gets the full channel list on Freeview.  Had a rather clever and functionally rich set up but then ditched the licence and went internet catch up based, with the added advantage I'm not allowed to watch the So-Called BBC!  Just remember to get a multi lbn with a satellite so you can watch and record multiple channels (I had a x4 lbn).  Can ground mount the dish.

Edited by No Duff

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48 minutes ago, DTMark said:

 

The antenna is still where it was, it hasn't moved at all nor been damaged. I don't suppose these things "wear out". Same TV and box. I don't think anything has changed here.

 

They do wear out (of sorts). The connection between the antenna and the coax corrodes over time leading to a gradual reduction in the quality of signal that gets through. If it has been up there for decades it may be worth considering a new installation.

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If you have weak signals then the tunners will attempt to seek out the strongest signal. Sounds like yours is just not correctly positioned, or not big enough, for the transitter / area that you have chosen.

You say that it is 50:50 split in your area. I would suggest the first thing to do is go knock on people's doors, ask them whether they are picking up London or Meridian news, observe the size of their aerial and the direction in which it is pointed. By doing this you should be able to quickly establish whether you need to alter the direction and/or buy a bigger aerial.

You migth discover, for example, that those near you trying to receive London are having all sorts of problems. But those receiving Meridian are just fine. Or vice versa.

Don't underestimate the importance of even an inch change in aerial direction.

Do this before buying a new aerial or buying a booster.

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I'd have thought you might be Hannington (your table is incomplete as it doesn't include transmitter power)

Anyway, the reason for the aerials pointing different directions is just as much to do with the strange way radio-waves behave.  The wavelength of TV signals is about 50cm, so you'd expect things bigger than 50cm (trees, houses, hills) to influence the signal.  Similarly, after a long enough signal path with multiple hills in the way, you expect moving the aerial about 50cm laterally would have a very large influence on signal strength.  You'd also find that pointing the aerial in a surprisingly different direction would also increase signal power (or, more likely, reduce the power of signals that have come via a different path (the other side of the hill) that act to decrease signal quality.

And it isn't as though those radio waves are always travelling through the same stuff -- the air will have different levels of humidity, which acts to influence the way it propagates.  Not much, sure, but all of a sudden the alternative route round the other side of a hill somewhere becomes the higher power path, and that competes with your chosen path -- effectively decreasing useful signal and destroying picture quality.  (other things also have an influence, but not as much as humidity).  

Anyway, I was only saying to my children the other day that in the future you'd expect to not see aerials on houses -- they'd all get their TV via internet. (But I seem to recall that you don't get good enough internet for TV...)

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Thanks all.

This photo is of the top of our house. Ours is the one in the foreground (semi-detached). Even here you can see the seemingly random alignment of the antennae; it's like this all through the village. 

antenna.jpg

Just one slightly oddball thought that occurs:

We also have a 4G antenna fixed to the eaves of the house. The picture is from before when it was fitted. It sits below the chimney on the eaves of the house sticking out.

The two look similar and are about the same size as each other. They don't both point exactly the same way. The cables do not run close together.

Is there any way in which one can "interfere" with the other?

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24 minutes ago, DTMark said:

The area we live in is some sort of "settled estate" which has certain rules which are enshrined in the tenancy agreement. One of those is 'no satellite dishes'.

Actually a couple of people do have them and have managed to find somewhere to 'hide' them so they're not so ugly as they would otherwise be.

We might be able to get away with it if we can put the dish on the side of the building at the end of the garden below the "fence line" quite low down as long as the coax can handle that length of run. And as long as it can "see" the satellite from there. There aren't any others nearby to get a sense of which way it would have to point. But it's a potential option.

We have London here, not Meridian. But I think the split in the village could well be 50/50 between those two. Neighbouring town can have either, here, you can generally only get one or the other thanks to the topography of the land.

I've never tried moving the antenna around to see if we can get something better but this still doesn't really explain why it is that channels are forever changing frequencies and the things need retuning all the time. Nor why the signal drops altogether on all channels at 20:40 every weeknight. It has been doing that for about a week now. Here's the result set from the DigitalUK website for this area. Guessing we're connecting to #3 in that list.

I'll give a local installer company a call later today - suspect they're very familiar with this "problem area".

 

  Name Region Parent Transmitter Grid Reference Distance (km) Bearing° Aerial Group Now Aerial Group After
Most Likely Transmitter Midhurst Meridian N/A SU 91222 24999 24 141 C/D H,T H B H,K H
Alternative Transmitter Crystal Palace London N/A TQ 33940 71220 64 64 A H,T H A H,T H
Alternative Transmitter Guildford London Crystal Palace SU 97475 48615 22 77 B V,K V B V,K V
Alternative Transmitter Reigate London Crystal Palace TQ 25640 52137 50 80 A V A V
Alternative Transmitter Hannington Meridian N/A SU 52740 56807 27 299 B H,T H B H,T H
Alternative Transmitter The Bournes Meridian Hannington SU 84232 45193 8 81 A V A V
Alternative Transmitter Heathfield Meridian N/A TQ 56680 22074 84 105 B H B H
Alternative Transmitter
  • Crystal Palace (Local Mux)
  •  
London Crystal Palace TQ 33940 71220 64 64 A H A H
Alternative Transmitter
  • Hannington (Local Mux)
  •  
Meridian Hannington SU 52740 56807 27 299 B H,T H B H,T H

Hard to believe there's a working transmitter in Guildford when the signal around Woking is crap. It only seems to be usable from very high mounted aerials with an amp. So blocks of flats with a communal aerial and booster are great, everyone else struggles.

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1 minute ago, Hail the Tripod said:

Hard to believe there's a working transmitter in Guildford when the signal around Woking is crap. It only seems to be usable from very high mounted aerials with an amp. So blocks of flats with a communal aerial and booster are great, everyone else struggles.

Alton is similar. I'm guessing the one 8km from here is the repeater/relay one that services that little part of Alton that can't get any signal otherwise. However that would be on the other side of the hill we live near the bottom of.

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Posted (edited)

When signal levels are weak, there are many factors that can affect reception, over or a long period of time down to instantaneous effects such as Rayleigh fading. Even a passing bus van have an effect. So can the weather. So can the construction of a nearby building. Or leaves on trees.

Everything you describe indicates that terrestrial signal is poor from all nearby transmitters.

There is little you can do besides using a higher gain antenna, perhaps a signal booster (I am sceptical about these, you boost the noise too) and very careful alignment of the antenna.

I think that your best technical option may be cable or satellite. Each of which, unfortunately, will involve a subsription.

Edited by Happy Renting

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Posted (edited)
22 minutes ago, Happy Renting said:

Each of which, unfortunately, will involve a subsription.

Just to clarify, subscription is optional.  

Freesat, like Freeview, is free (the cost is included in the box or, if you have it, TV).  The Astra signal is transmitted unencrypted in clear (free to air).  You can also buy non Freesat boxes or computer cards requiring no subscription but these will not auto retune moved channels (part of the Freeview/Freesat spec).

Catchup TV for ITV, Channel 4, More 4, Channel 5, BBC (with licence) are free of subscription, although not all broadcast programmes are available.  Most/all also have live streams but the law requires a TV licence to view these. They all can be watched via the net on TV, either via a smart TV, Chromecast (changes and/or depends on android device), or other box.

The broadcast channels are indeed also available on Sky, Amazon(?), Netflix(?), etc as part of a wider subscription package.

 

Edited by No Duff

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Posted (edited)
2 hours ago, The Masked Tulip said:

I think you're going to need as bigger aerial.... lol.

Do you consider yourself in London or in the Meridian region? The strongest signal for you is the Guldford transmitter which is part of the Crystal Palace network. It would mean that you would get the London TV channels including the London news stories.

If you consider yourself in the Meridian area then you will be wanting to have the TV channels and news from those areas but that means that you aerial will be pointing at transmitters that will be giving you weaker singals.

Deciding which of the above you are currently receiving and which you want to receive affects any decisions that you can make to rectify this.

Currently in the UK there is a lot of transmitter work underway which iscausing interruptioons. Also, the unusual area of high pressure over the country is also affecting TV signals. That yours is disconnecting at the same time each night for a matter of seconds indicates that something is going on at the transmitter relay that you are using.

Decide what channels you want to receive and:

1. You might need to re-point your aerial.

2. You might need a bigger aerial.

3. You might need a booster to boost the signal.

These are the folks who run the transmitters. All the info you need will be here - http://www.digitaluk.co.uk/

My Mum has exactly this problem and actually has two aerials, one pointed at the   London transmitters and one at Meridian. She has to use an aerial booster as well. I can't get a mobile signal in her house either even though the nearest 4G transmitter is less than 2 miles away because they built it lower than the hill at the back of he house. Of course, the problem would be solved if the transmitter had been stuck on top of the Surrey greensand hills nearby which is one of the highest parts of southern England but I assume nimbies and planners have vetoed it so that we can continue to enjoy technology of the 1950s.

Edited by Virgil Caine

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8 minutes ago, No Duff said:

Just to clarify, subscription is optional.  

Freesat, like Freeview, is free (the cost is included in the box or, if you have it, TV).  The Astra signal is transmitted unencrypted in clear (free to air).  You can also buy non Freesat boxes or computer cards requiring no subscription but these will not auto retune moved channels (part of the Freeview/Freesat spec).

Catchup TV for ITV, Channel 4, More 4, Channel 5, BBC (with licence) are free of subscription, although not all broadcast programmes are available.  Most/all also have live streams but the law requires a TV licence to view these. They all can be watched via the net on TV, either via a smart TV, Chromecast (changes and/or depends on android device), or other box.

The broadcast channels are indeed also available on Sky, Amazon(?), Netflix(?), etc as part of a wider subscription package.

 

I stand corrected. I rarely watch telly. I don't have a BBC Propaganda Subscription Permit.

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Posted (edited)
5 minutes ago, Happy Renting said:

I stand corrected. I rarely watch telly. I don't have a BBC Propaganda Subscription Permit.

Me neither.  I built a very good technical set up, then had enough of the So-Called BBC and adverts so cancelled my licence, retreated to catch up, and now don't do much of that either.  I honestly don't know how I had the time for TV, especially live TV.

Edited by No Duff

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On 25/06/2018 at 10:53, The Masked Tulip said:

I think you're going to need as bigger aerial.... lol.

Do you consider yourself in London or in the Meridian region? The strongest signal for you is the Guldford transmitter which is part of the Crystal Palace network. It would mean that you would get the London TV channels including the London news stories.

If you consider yourself in the Meridian area then you will be wanting to have the TV channels and news from those areas but that means that you aerial will be pointing at transmitters that will be giving you weaker singals.

Deciding which of the above you are currently receiving and which you want to receive affects any decisions that you can make to rectify this.

Currently in the UK there is a lot of transmitter work underway which iscausing interruptioons. Also, the unusual area of high pressure over the country is also affecting TV signals. That yours is disconnecting at the same time each night for a matter of seconds indicates that something is going on at the transmitter relay that you are using.

Decide what channels you want to receive and:

1. You might need to re-point your aerial.

2. You might need a bigger aerial.

3. You might need a booster to boost the signal.

These are the folks who run the transmitters. All the info you need will be here - http://www.digitaluk.co.uk/

It's the cable not the antenna.

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4 hours ago, sarahbell said:

It's the cable not the antenna.

Yep, best to use double screened coaxial and if you can avoid a wall plate and run the cable direct into the TV. If you do need a wall plate buy a decent one that is screened.

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On 25/06/2018 at 10:49, Byron said:

I also used to have an amplifier for the mobile phone but got busted by Ofcom who told me that phone ones are illegal.

I’m amazed they’re actually out looking for things like that (unless it was causing some kind of technical problem with equipment somewhere).

How long did they take to find it? 

They just send you a polite letter to cease and desist? 

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On 25/06/2018 at 10:49, Byron said:

I have an antenna amplifier in the loft.

It is the only way that I get a sufficiently strong signal.

I also used to have an amplifier for the mobile phone but got busted by Ofcom who told me that phone ones are illegal.

So did I. £5,000 fine or they can just take it away... They took it away! xD

Two of them turned up with a laptop connected to some scanner. Not threatening and no police involved. 7 out of 10 = pleasant fascists.

single_band_mini_1-e1431260221357-768x566.jpeg.722d5c1216b26c8ca5b26d234021d8c5.jpeg

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Posted (edited)
34 minutes ago, XswampyX said:

So did I. £5,000 fine or they can just take it away... They took it away! xD

Two of them turned up with a laptop connected to some scanner. Not threatening and no police involved. 7 out of 10 = pleasant fascists.

single_band_mini_1-e1431260221357-768x566.jpeg.722d5c1216b26c8ca5b26d234021d8c5.jpeg

They probably are looking for spoof towers that track phones illegally, and these effectively look just like them. There’s been a bit of a thing in Washington about someone using those kinds of devices to identify phones going into federal buildings and then tracking their subsequent movements.

Edited by Hail the Tripod

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On 25/06/2018 at 11:16, DTMark said:

Nor why the signal drops altogether on all channels at 20:40 every weeknight.

Only on a weeknight? Do you have something electrical kicking in at that time? Hardly likely to be central heating in this heat, hot water...?

 

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A satellite dish would need to be pointed more or less due south. Freesat ought to solve all your problems if you can find somewhere to hide the dish.

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