cancel
Showing results for 
Search instead for 
Did you mean: 

RF noise from next door

Ransomefan
Grafter
Posts: 81
Registered: 24-06-2011

RF noise from next door

When I can see next door switch on their large screen TV my noise margin decreases by about 5db and when they switch it off the margin goes up from about 15db to 20db. This means I have a low sync on my router and an IP profile of 2000kbps which is about half I can get when they are on holiday.  They are on Sky.  Could connecting the sky box to the phone line without a filter cause this? Is the filter the usual 'soap on a rope' ADSL filter and could it help if I fit one for them?  They do not have broadband.
6 REPLIES
Community Veteran
Posts: 5,600
Thanks: 620
Fixes: 1
Registered: 21-03-2011

Re: RF noise from next door

Here's a shielding supplies firm.... http://www.emfields.org/index.asp If you are not using Wifi you could enclose your router in a small grounded faraday cage.
I can recommend professional stuff used in the construction of faraday cages, but that tends to get expensive. Did one in Moscow and it added 150k Euro to the bill.
Now Zen, but a +Net residue.
Ransomefan
Grafter
Posts: 81
Registered: 24-06-2011

Re: RF noise from next door

Wow, that looks an expensive solution. I made a Faraday cage according to some instructions I found on the net and earthed it via mains plug.  It certainly eliminated my mobile phone signal and the noise margin on the router showed that some of the varaiable noise was eliminated but  the overall level had no significant change.  Thanks for the suggestion though and I enjoyed learing more about Faraday cages and making one.
[Moderator's note by Jim (Oldjim):  Full quote of preceding post removed, as per Forum Rules ]
Community Veteran
Posts: 6,735
Thanks: 12
Registered: 02-02-2008

Re: RF noise from next door

It could well be crosstalk between your phone lines rather than directly-radiated RF.
In which case a filter (or 2) on their sockets could well help.
It's worth going round, explaining the problem and making the offer.
I had terrible interference on my line a while back due to crosstalk generated by a faulty router at my neighbours house.
Ransomefan
Grafter
Posts: 81
Registered: 24-06-2011

Re: RF noise from next door

Quote from: HPsauce
It could well be crosstalk between your phone lines rather than directly-radiated RF.
In which case a filter (or 2) on their sockets could well help.
It's worth going round, explaining the problem and making the offer.
I had terrible interference on my line a while back due to crosstalk generated by a faulty router at my neighbours house.

Thanks for your help.
Went and had a chat with two new filters in hand. My wife watched RouterStats noise margin whilst I did tests.  Their Skybox was plugged in via a filter. First I unplugged the filter from the extension socket and waited one minute (no change seen), then I plugged Skybox and phone into a new filter (no change) and finally put a second new filter in as well as the first.  I then phoned  my wife who had observed no change at all steps (which I later confirmed).  I did note this morning when he turned his TV off my margin went up by about 8db and it dropped down when he returned and switched it on.
So Faraday cage and fresh double filters made no difference.  Anyone any other ideas? The neighbours were very helpful and were prepared to help whatever way they could apart from not watching TV!.  I have given up hoping to solve this before my connection to Plusnet goes live - hopefully in the next  2-3 days.
Community Veteran
Posts: 6,735
Thanks: 12
Registered: 02-02-2008

Re: RF noise from next door

Does their phone wiring pass near the TV, it could be picking up radiated interference?
Also, have they done the "bell wire modification", though I think that's unlikely to do much.
Ransomefan
Grafter
Posts: 81
Registered: 24-06-2011

Re: RF noise from next door

Quote from: HPsauce
Does their phone wiring pass near the TV, it could be picking up radiated interference?
Also, have they done the "bell wire modification", though I think that's unlikely to do much.

The phone extension line is within about a metre of the TV and I would agree that radiated interference from the TV is highly likely.  It is an enormous  - well 55 inch guestimate-Samsung TV .  Can't tell my plasmas from my LCDs.  Hopefully fibre will help a little (March next year) as I am on a long line (51db atten.) to start with.