[pmh80]

http://m.bbc.co.uk/news/technology-21410743

So how are people going to find out if they going to lose out and have to be moved to an alternative, what about people who just moved to youview with bt and talktalk , I live in valleys and have a poor signal at the best of times .

I want Freeview not freesat and there's no cable up here in the valleys

I've had a look for Digital Mobile Spectrum Limited (DMSL) and no sign just yet .

[joshua_welby]

Originally Posted by pmh80

http://m.bbc.co.uk/news/technology-21410743

So how are people going to find out if they going to lose out and have to be moved to an alternative, what about people who just moved to youview with bt and talktalk , I live in valleys and have a poor signal at the best of times .

I want Freeview not freesat and there's no cable up here in the valleys

I've had a look for Digital Mobile Spectrum Limited (DMSL) and no sign just yet .

DMSL does exist and will be until 2018 see their website http://at800.tv/

[Nigel Goodwin]

Originally Posted by pmh80

http://m.bbc.co.uk/news/technology-21410743

So how are people going to find out if they going to lose out and have to be moved to an alternative, what about people who just moved to youview with bt and talktalk , I live in valleys and have a poor signal at the best of times .

I want Freeview not freesat and there's no cable up here in the valleys

I've had a look for Digital Mobile Spectrum Limited (DMSL) and no sign just yet .

Just wait and see what (if anything) happens - there's seems a LOT of people running round proclaiming 'the sky is falling'

[Spot]

If it turns out to be a serious issue, they will have to do something to sort it out. It may well be no issue at all.

[phil solo]

Be on the alert for unscrupulous marketing campaigns from a certain satellite TV company trying to convince you that your Freeview signal is about to vanish forever.

[anthony david]

Amazon have started selling the SAC AE5100 filter for £9.99, if you have interference problems this may be all you need to clear it. In the mean time wait and see, you may not have any problems anyway.

[joshua_welby]

Originally Posted by Spot

If it turns out to be a serious issue, they will have to do something to sort it out. It may well be no issue at all.

That is right, this is the second time this has happened, the last time was just before they were rolling out the TETRA Radio Services for the Emergency services,
I do not remember that had too many complaints after that launched, certainly not in the numbers that they were talking about at that time anyway

[pmh80]

Originally Posted by joshua_welby

DMSL does exist and will be until 2018 see their website http://at800.tv/

Thank you joshua_welby that is great ill read this page soon

[pmh80]

And trust me ,I'd let jaws eat me first before I sign to sky !

[albertd]

Originally Posted by pmh80

And trust me ,I'd let jaws eat me first before I sign to sky !

You don't have to sign up to Sky to get satellite.

Freesat is a non-Sky satellite service which will not be affected by 4G whatever happens.

[Spot]

Looking through a few of the OPs' previous posts on this topic, it appears Risca is the transmitter in question , which uses UHF channels 43, 46 and 50, so this really is a situation where there is almost certainly nothing to worry about.

[Luis Essex]

Why do you believe that?

To quote from Ofcoms "Coexistence of new services in the 800 MHz band with Digital Terrestrial TV"

"A DTT receiver becomes overloaded if the power of the signals at its input exceeds a certain threshold. In the presence of overload, a DTT receiver stops working altogether and reception of all DTT services is lost."

http://stakeholders.ofcom.org.uk/bin.../dttcondoc.pdf

[Nigel Goodwin]

Originally Posted by Luis Essex

Why do you believe that?

To quote from Ofcoms "Coexistence of new services in the 800 MHz band with Digital Terrestrial TV"

"A DTT receiver becomes overloaded if the power of the signals at its input exceeds a certain threshold. In the presence of overload, a DTT receiver stops working altogether and reception of all DTT services is lost."

Pay attention to the undermined/bold section.

You would most likely need a pretty high power 4G transmitter, very close to the receiving aerial, to cause any problems, and likely only over a VERY small area.

But as I've repeatedly said - wait and see what happens - it's likely to be Y2K all over again.

[pmh80]

Y2k again good grief, I still got the y2k book somewhere lol ill look it up and see what it says !!!

I have tried freesat and though it was a load of old tosh no dave ,no quest ,no yesterday . There was more tv shops that anything else . Call me picky but I thing Freeview is awesome

[Nigel Goodwin]

Originally Posted by pmh80

I have tried freesat and though it was a load of old tosh no dave ,no quest ,no yesterday.

You mean just like the vast majority of Freeview transmitters

Only a small minority of Freeview transmitters provide those channels, Freesat is there for those who can't get those main transmitters. 'Hopefully', one day, those channels will become available on Freesat, but currently the subscription money is subsidising the Freeview versions.

[MartinPickering]

I'm writing an article about this for the next SatCure "blog", if anyone is interested.

Basically, if you are planning to install a masthead amplifier and you are close to a potential 4G mast (nobody knows yet which masts will be used) then you might like to fit a 4G filter between aerial and amplifier as a precaution. Better still - if you are receiving Group A or B transmissions, fit a Group A or B passband filter instead.

In all other circumstances, you should wait and see. IF you have problems and IF one or more filters is the answer, it/they will be easy to fit except on a TV aerial pole.

Note that fitting a filter will free up the channels that it blocks so that you can safely use them for piping TV (e.g. Sky RF) round the house without risk of interference.

Note that plans are already being made for the government to supply free filters as required. However, I don't know whether this will include fitting (i.e. someone climbing on your roof if necessary) nor whether you'll get a filter for every TV if required.

[Nigel Goodwin]

Originally Posted by MartinPickering

Note that fitting a filter will free up the channels that it blocks so that you can safely use them for piping TV (e.g. Sky RF) round the house without risk of interference.

Filters 'REDUCE' the signal Martin, not 'STOP IT', if it was strong enough to cause problems in the first place, it's unlikely it would be reduced enough to free that channel for use around your aerial system.

[MartinPickering]

I'm trying to keep this simple so the average person can understand it.

I have the specification for both 4G filters currently available, and the bandpass filters, and the average attenuation of around 55dB is sufficient to reduce any unwanted Freeview "digital" signal to a level that will not cause "snow" (the usual effect) on the analogue picture. Bear in mind that these unwanted Freeview signals are likely to be lower than the wanted signals to begin with, since the aerial won't be aligned on the unwanted transmitter(s).

In most locations, the 4G filter will also "free up" channels 61 - 69 for "piping TV".

[Mickey_T]

Originally Posted by pmh80

Call me picky but I thing Freeview is awesome

It is if you've still got a CRT.

Sadly freeview is mostly unfit to view on modern tv's due to the appalling picture quality.

I find Dave, Quest and Yesterday almost unwatchable due to the atrocious picture pushed upon the viewer. That goes for all COM mux channels too.

[reslfj]

Originally Posted by MartinPickering

Basically, if you are planning to install a masthead amplifier and you are close to a potential 4G mast (nobody knows yet which masts will be used) then you might like to fit a 4G filter between aerial and amplifier as a precaution.

The keyword her is 'yet'.

Originally Posted by MartinPickering

Better still - if you are receiving Group A or B transmissions, fit a Group A or B passband filter instead.

The aerial groups is a leftover from the analogue times. The allocation of channels in the same aerial groups for DTT was done to (almost) eliminate the need for new aerials at DSO.

Except in a few areas having a very,very week signal fitting a one-size-up wideband will work nicely.
The new and coming W60 (ch21-60) aerials will - I think - be the best for almost all new installations.

Ofcom may well replan all DTT into the ch21-48 spectrum from around 2019-2020, if the 700 MHz band must be cleared. This may well require large DVB-T2 SFN's using channels unrelated to the present aerial groups.

Ofcom expects all new aerials to be wideband or W60. Some group B aerials works rather well when receiving group A channels and will also work in a future ch21-48 DTT environment.

Originally Posted by MartinPickering

In all other circumstances, you should wait and see. IF you have problems and IF one or more filters is the answer, it/they will be easy to fit except on a TV aerial pole.
... (i.e. someone climbing on your roof if necessary) nor whether you'll get a filter for every TV if required.

The talk has been around one filter per household and som e extra help in a few very difficult/impossible cases.

The filter needed will depend on

• the DTT channels used in your area (ch 58-60 used/notused)
• the distance/direction to the 4G/LTE800 TX site and its ERP (power)
• the use of the 791-801 MHz from the 4G/LTE800 mast in question (telco dependent)

If channel 58-60 is used and the mast uses the 791-801 MHz for download you will need a special filter. I don't think the AE5100 filter will be af any use is this situation.

Otherwise a simple and inexpensive lowpass filter will do.

The filter must be fitted between the aerial and the first amplifier - masthead or the RF amplifier inside the STB/IDTV.

Lars

[Nigel Goodwin]

Originally Posted by MartinPickering

I'm trying to keep this simple so the average person can understand it.

I have the specification for both 4G filters currently available, and the bandpass filters, and the average attenuation of around 55dB is sufficient to reduce any unwanted Freeview "digital" signal to a level that will not cause "snow" (the usual effect) on the analogue picture. Bear in mind that these unwanted Freeview signals are likely to be lower than the wanted signals to begin with, since the aerial won't be aligned on the unwanted transmitter(s).

In most locations, the 4G filter will also "free up" channels 61 - 69 for "piping TV".

It's not 'unwanted Freeview' it's massively high powered 4G transmitters which is 'potentially the problem' - I doubt 55dB would be enough to prevent it interfering with analogue signals fed round the aerial system - it's simply designed to try and stop cross modulation in the front end.

[TallDave]

Originally Posted by Nigel Goodwin

It's not 'unwanted Freeview' it's massively high powered 4G transmitters which is 'potentially the problem' - I doubt 55dB would be enough to prevent it interfering with analogue signals fed round the aerial system - it's simply designed to try and stop cross modulation in the front end.

..and, ironically, the greatest interference to DTT occurs when the 4G transmitter is "idle".

[Nigel Goodwin]

Originally Posted by TallDave

..and, ironically, the greatest interference to DTT occurs when the 4G transmitter is "idle".

Does it?, and how would you know?

[TallDave]

Research shows that to be the case. Telcos could mitigate the impact to a certain extent by transmitting dummy data from the LTE basestation when it's not busy. However, they'll have no control over the behaviour of an idle phone; although the impact of phone-DTT interference is less significant than basestation-DTT interference.

[TallDave]

Originally Posted by TallDave

Research shows that to be the case. Telcos could mitigate the impact to a certain extent by transmitting dummy data from the LTE basestation when it's not busy. However, they'll have no control over the behaviour of an idle phone; although the impact of phone-DTT interference is less significant than basestation-DTT interference.

To clarify the above a bit better (with hindsight!), the impact of LTE interference is most likely to be total loss of a multiplex, whether it's from a basestation or a handset. But what I was trying to get at was that basestations will cause more problems than handsets.

And you can always turn off your 'phone if you want to watch TV ;-) You can't turn off the basestation!