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[Weaver]

In some situations, I find it difficult to physically keep mains away from RJ11 cables or ethernet cables.

* Ethernet cables screened: I'm switching to screened ethernet cables, Cat6a or Cat6, whatever I can get. I have seen (Cat7a ?) cables that have foil packets around each pair and braiding or an overall foil shield around the whole lot too. But I believe that if I were to go for Cat7a cables, I would need to find one with Cat6a plugs (normal-looking ones) fitted, instead of the weird high-speed new Cat7a design which is physically incompatible with normal RJ-45 sockets. So kind of mongrel cable. Too much grief probably, and for what reward?

Anyway the idea of using heavily shielded Ethernet cables might mean I don't have to worry about  mains cable adjacency, or crosstalk between ethernet cables in a bundle. Is that correct/achievable?

* Mains cable itself: Is there anything I can do about screening mains cables themselves? Sounds utterly mad. Hifi shops sell voodoo mains cables with shielding and magic psychic powers beyond electronics as we know it. These would be ideal if all my equipment had kettle-type plugs (what are they properly called?) on the equipment end, but failing that, I wonder if there's anything I can botch together after the fact? Some kind of wrapper that can be earthed at the mains plug end?

* Mains vs RJ-11 DSL signal: As for trying to shield RJ-11 cables, ie the modem to wallsocket cables, I've bought the ADSLNation / Tandy shop (adslnation.com) RJ11-RJ11 cables which are claimed to be shielded. I’m not confident that I could risk putting mains anywhere near these cables. Agree?

[The cable from your router to the rest of your LAN is ethernet with RJ-45 plugs on it, not RJ-11 which is slightly smaller than RJ-45. If you have a separate modem and router, the cable between them is ethernet too, with RJ45 plugs and sockets. Only the modem-to-wallsocket DSL signal cable is RJ11.]

[AArdvark]

Question:

Are you trying to solve a particular problem or is it a nice to have. ?

The typical 'rats nest' of cables many people have does not seen to be a problem.
So unless you are doing something ultra-high speed (off-spec) over the cables and/or they are being used in a strange way where there is no margin for re-tries etc I am not sure what to say.

Simply use good quality cables with good quality connectors. (Both mains and network)
If you have seen some of the messes people have in offices where they should know better and they still work OK you would be surprised.
(That is working without sending 'crap' back down the cable to the rest of the world. )

[Weaver]

@aardvark  - a nice-to-have? Possibly.

1. I'm trying to shield things enough that I don't have to worry so much about keeping mains cables away from ethernet cables.

2. I don't want to pay the cost of retries, as TCP retransmissions cost a lot because I pay for bytes downloaded and the WAN link is very slow (< 2Mbps per line * 3 lines). So the last thing I need is an error introduced locally.

3. The DS attn is >63.5dB so that means a very weak signal and so relatively very susceptible to noise injected at the user end. People with normal, good quality DSL links don't have to worry nearly so much, as their DSL signal voltage is high relatively speaking.

[Weaver]

Things are so critical, small things. For example, if I could attain another 32kbps or two on a line, it would push me up to the magic 2272 ds sync which is the threshold for BTW 20CN IP Profile 2000 instead of 1750, so a small improvement could give me an extra 0.25 Mbps, or even times 3, if I could succeed on every line at the same time.

But (i) taming mains, the madness thereof and (ii) protecting my ethernet, that's the nub of my questions in this thread.

[AArdvark]

Sorry, I did not realise your connection was so bad !

In that case you need to Faraday cage each and every one of you cables <jk>

You are paying a lot to get so little. 

There must be extra shielded cables available or possibly get them custom made as all the raw materials will be available.
Are you any good with a soldering iron or know someone who is ?
(Not me, I couldn't solder 2 wires together cleanly without using 2lbs of solder. even worse if I was forced to work in metric  )

[Weaver]

@Aardvark  - As I mentioned earlier, there are lots and lots of hifi voodoo mains leads pre-made, but if you have equipment without a removable mains lead, no IEC connector on it, then you're stuck unless you want to start dismantling kit just to get the mains lead off.

[I used to be good with a soldering iron, occasionally had to at work. But these days disability (pain drugs) means that I'm semi-bedbound.]

So I was wondering about a more creative, ie Heath Robinson, solution. I had thought about wrapping a mains cable in broad copper tape and earthing that, somehow.

I pay ~£150 pm for a total of 5.25Mbps, three lines ADSL1 20CN with BTW Premium and that's enough throughput to be able to watch Netflix etc in high quality.

[AArdvark]

I didn't mean the 'garbage' hi-fi stuff, I know what you mean.
I don't believe any of the 'Magic Science' for all that rubbish.

Don't have enough knowledge to say whether the homemade approach would actually work !
I am sure there are people on kitz who would be able to say whether there is any point in trying to do what you ask.

 

[Weaver]

Actually I found, after a lot of advanced googling, that the mains screening idea isn't totally mad, as I dug up three companies - ZipperTubing, Kemtron and Kitagawa - who make just what I need. Wraps for cables with conductive EMI insulation. The problem is I have no idea how to buy any. I don't need 25m of anything, and even then I would need a product that is in a shop.

[AArdvark]

With a little google-fu I have found.

http://www.wireandstuff.co.uk/products/Knitted-Wire-Mesh.html

Any good ?

[AArdvark]

I did say Faraday cage

[Weaver]

> Any good ?

Very useful. some of the other products have a velcro fastener so you can just warp the conductive jacket round the cable and then it fastens to itself, so very neat.

[les-70]

   Noise ingress occurs in various ways.  My biggest mains related benefit (biggest but not big) comes from running the modem and router, usually a HG612 and Dlink Dir-655, on a BT mains conditioner. The mains conditioner seems best, if contrary to recommendations,it is unearthed!

 I get another a benefit  if there is NO extra wired ethernet connection to the modem/router but with all access wireless.   I guess this set up is close to running on batteries.  This has not proved a disadvantage for me but as a matter of principle I do prefer a wired connection.

  BT mains conditions are on ebay about £25.  They can make a slight hum. I put damping pads on the metal sides and placed the unit on top of a bubble pack bag. The hum is then insignificant - I can't hear it unless my ear is right by it.

  Things like this never work the same for all lines but it may be worth a try in extracting all the speed you can.

[JGO]

Screening  is of three broad types, Electric,Magnetic and Electromagnetic. It has to be designed for a purpose, not just used as "A Good Thing" .( AFAIA a Faraday shield is used exclusively to protect people working on live Power Grid cables. At RF it would be ineffective)   

The "Radio Frequency Interference Handbook" by R.E.Taylor published by NASA or the RSGB Interference Handbooks are useful references.  However the understanding has to be at all stages; I've lost count of the adequate connection ruined when someone treated it as a bit of house wiring or the screen that didn't work because "3 screws will hold it !".

Alternatively if the source of interference can be identified and suppressed this may help several users

[Weaver]

@les-70  -mAny thanks for that excellent tip.

I currently use two levels of mains conditioning, nearest to the three modems is a Tacima mains block (some hifi enthusiasts have been known to use these if memory serves) and then behind that is a Belkin PureAV mains block, and behind that a chunky APC UPS.

I'm trying to keep any mains cables away from the cables to the modems and away from ethernet cables. The modems have little power blocks (possibly switched) on three pin plugs and dc cables going to thr modems themselves, so hopefully not a source of interference, but the modem dc cables have ferrites on them just in case. The only actual mains in this area is the mains to the router, a Firebrick FB2500, and the Netgear gigabit switch. I suppose I could lengthen the appropriate Ethernet cables and move the router and switch further away from all the modems, which would give the modems a solitary space free of other nearby kit.

[GigabitEthernet]

My biggest mains related benefit (biggest but not big) comes from running the modem and router, usually a HG612 and Dlink Dir-655, on a BT mains conditioner. The mains conditioner seems best, if contrary to recommendations,it is unearthed!

Just out of interest, how large is the BT mains conditioner?