Ok - so looking for a steer on this.

Our main transmitter is Sandy Heath (East).

The aerial on the house is in good condition and is undisturbed.

Close by there (as in less than 1/4 mile away) is a mobile mast which I believe is now providing a 4G service.

Recently - as in the last 3-4 months - we are experiencing problems with channels which are on the higher 'MUXes' e.g. SDN which are broadcast on Ch52 (I think).

The MUXes further down the scale don't seem to have any problems - which is why I don't think the aerial is the problem.

Is it worth trying a 4G filter or is that unlikely to make a difference?

For the low cost of a filter (and if you ring up you can probably even get one for free?) it's worth a try.

I had wondered the same - from what I've read 4G should only be affecting those MUXes on Ch 60 upwards - or have I misunderstood Nigel?

As you say, they can be picked up for a fiver from a well known auction site - might just give one a go to find out.

There shouldn't be any muxes on 60 upwards as that was the part of the TV band flogged off for 4G usage. So it can affect channels in the high 50s if there is indeed a 4G 800MHz transmitter nearby.

And 4G does not necessarily mean it is using the 800MHz former TV band either. There are a range of frequencies that 4G can use, most well out of harms way (or should be) from the TV bands.

The point is that a VERY strong signal from a VERY close 4G mast 'could' swamp the front end of the tuner.

Have a look here, for what to do:

https://at800.tv/

OK - so the filter arrived - fitted it - and it actually made things worse - i.e. completely knocking out the channels in question.

Tried moving it from the feed into the distribution amp into the feed into the TV only - still no improvement.

I'm pretty convinced the problem is the phone transmitter - which is right in our line of sight - i.e less than 1/4 mile away - any ideas what I can do next?

I have a suspicion about the aerial .....
Do your neighbours have the problem?
If so all Contact at800. Again and tell them
https://at800.tv/contact-us/

They on behalf of the mobile industry are the people who can take action ....
Tell them the model of the tv and if you can signal level and error rate on a few muxes ...
But be prepared to say that your suspect mast is not emitting 4G.

Daft question alert

You did fit the filter the right way round?

Just watched the video on their website and the labelling of the filter seems a bit counter-intuitive to me. The A socket connects to the amplifier/TV/STB input and the B socket to the aerial.

Normally you talk of going from A to B so you would think A would be the aerial end and B the amplifier/TV/STB end. Given that that the direction the signal flows is from aerial to amplifier/TV/STB. So going B to A seems backwards to me!

If the filter kills everything and is fitted the right way round then only two possibilities. The filter is cream crackered or your aerial signal is. There is likely to be some signal loss even with a fully functioning filter. But it shouldn't be too bad with a decent signal. So if the filter is working properly but kills the TV signal then that would suggest a pretty poor signal to start with.

What sort of signal strength does the TV report with the filter removed? If it is above 40-50% then even with the filter in circuit you shouldn't see a total loss of channels. But if it was down around 30% there is a possibility it could have a serious effect.

No - not daft question at all - I did check it and am sure it's the right way - always worth asking the dumb questions though !

As for signal strength - over 50%, usually between 50% and 100% (varies by MUX as some of them aren't as strong as others).

It's not at all obvious from the video whether the filter has a male socket one end and female the other so in theory you couldn't get it wrong as the aerial plug should be male so won't fit a male socket.

If it does have opposite gender sockets on each end then that makes it less likely the filter is the wrong way round. So it could be faulty. Or the lead they provide to plug into the amplifier/TV/STB is faulty. If you have a suitable replacement lead might be worth giving that a try just in case. Otherwise it does sound like the filter is faulty if it kills the signal. 50% plus signal strength should be OK.

Have you changed your aerial to a Wideband Group one ? http://www.ukfree.tv/transmitters/tv/Sandy_Heath

http://www.tradeworks.tv/acatalog/Vi...al-4G-LTE.html

I like the SLX range as I think it offers good value for money and maybe a time for an update ?
http://www.amazon.co.uk/SLx-27824BMG...rds=slx+4g+amp

That and some WF100 cable will help you out

It is obviously not 4G interference, which anyway has been an over hyped scare mongering tactic.
A passive filter should not be directional, it has a male and female end for convenience only.
Time to check your aerial and cabling.