Kitz Forum
Broadband Related => Telephony Wiring + Equipment => Topic started by: Weaver on August 08, 2015, 02:21:54 AM
-
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.]
-
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. :) )
-
@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.
-
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.
-
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 ;D)
-
@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.
-
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. ;D
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.
-
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.
-
With a little google-fu I have found.
http://www.wireandstuff.co.uk/products/Knitted-Wire-Mesh.html (http://www.wireandstuff.co.uk/products/Knitted-Wire-Mesh.html)
Any good ?
-
I did say Faraday cage :) :)
-
> 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.
-
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.
-
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
-
@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.
-
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?
-
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
Off topic slightly.....
Can/have you tweaked the target SNRM of your modem(s) that is what I do to gain either stability (get as close to 6240 kbps) or speed (get just above 6816 kbps).
On my hg635 I issue the command xdslcmd start --up --snr 120.
What does your SNRM drop to at its lowest at night ?
Do you monitor your modem(s), or because they are in modem only mode behind your firebrick it is too difficult?
Ian
-
Just out of interest, how large is the BT mains conditioner?
12 cm high, 19 cm long, 14 cm wide (plus mounting flanges)
Weight: 4.8 kg
-
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 was never able to detect a benefit from a "Tacima", I wonder if it is the isolation provided by the Mains Conditioner rather than its filtering that gives a benefit. The fact that it seems best with the output un-earthed suggests that.
-
Just out of interest, how large is the BT mains conditioner?
12 cm high, 19 cm long, 14 cm wide (plus mounting flanges)
Weight: 4.8 kg
They are a not something that you would want on view. Mine sits on the floor out of sight behind a desk pedestal.
-
. . . had kettle-type plugs (what are they properly called?) . . .
That would be an IEC connector (https://en.wikipedia.org/wiki/IEC_60320), either C13 & C14 or C15 &C16.
-
Just out of interest, how large is the BT mains conditioner?
Here are a couple (http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2055119.m570.l1313.TR0.TRC0.H0.XBT+Mains+Conditioner+.TRS0&_nkw=BT+Mains+Conditioner+&_sacat=0) of single-socket versions. I have seen them with 1, 2 or 4 socket outlets. The physical size is directly proportional to the number of socket outlets.
-
That's the one I've got, for which I quoted the dimensions.
-
That's the one I've got, for which I quoted the dimensions.
I was not aware that you are also an owner and user of one of those devices. What device(s) do you have powered thorough the conditioner, please?
The dimensions that you have quoted along with the images via the eBay link should show that they are not small devices that can be discreetly tucked away.
-
I'm looking at purchasing something like this (http://www.amazon.co.uk/Tacima-6-Way-Mains-Conditioner-Protection/dp/B00UB0G4DQ/ref=sr_1_2?ie=UTF8&qid=1439048208&sr=8-2&keywords=mains+conditioner) as I need a new extension plug anyway.
Would this be as good as the BT option?
-
I don't think so. I could not detect any impact from using that one but I had a clear benefit from the BT unit. Also neither will make any difference unless you have the sort of noise that they mitigate. You really just have try one or the other and see.
-
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
Can/have you tweaked the target SNRM of your modem(s) that is what I do to gain either stability (get as close to 6240 kbps) or speed (get just above 6816 kbps).
What does your SNRM drop to at its lowest at night ?
Do you monitor your modem(s), or because they are in modem only mode behind your firebrick it is too difficult?
I can monitor the stats on my modems, because A&A's servers can interrogate them, god knows how, remotely and get sync rate, SNRM, all the stuff I need. I check on them all once a week or so. SNRM doesn't drop much at night, below 6dB to 5 occasionally. Sometimes it is 7dB all day.
As for issuing tweaking commands to all the modems, experience suggests that that would be a step too far. I've had a bad experience (documented in an earlier thread, where?) where ds sync at 2240 or similar was basically too high and needed to be reduced (by a short off-on, luckily) slightly which brought a huge ES rate down to zero for the loss of a few k ds sync (which equals zero as it's in the same band).
-
I'm looking at purchasing something like this (http://www.amazon.co.uk/Tacima-6-Way-Mains-Conditioner-Protection/dp/B00UB0G4DQ/ref=sr_1_2?ie=UTF8&qid=1439048208&sr=8-2&keywords=mains+conditioner) as I need a new extension plug anyway.
That's what I have for the modems, with a Belkin PureAV behind it (about £40).
-
Also neither will make any difference unless you have the sort of noise that they mitigate. You really just have try one or the other and see.
Try a 12v spare car battery 1st as the noise may not be coming in on the mains.
-
That's the one I've got, for which I quoted the dimensions.
I was not aware that you are also an owner and user of one of those devices. What device(s) do you have powered thorough the conditioner, please?
The dimensions that you have quoted along with the images via the eBay link should show that they are not small devices that can be discreetly tucked away.
As you say, they're substantial, heavy units, better suited to industrial use than domestic.
I bought mine because I have a recurring issue with spikes on my upstream SNRM and I wanted to test if these were the result of mains spikes. I live in a rural area with rather dodgy mains supplies. I used it to supply power to my modem/router and network switch, and it made not a jot of difference. It's now packed away in a cupboard.
-
I was also going to suggest testing with a car battery, but see NS beat me to it. Just make sure all the equipment is 12v
-
As you say, they're substantial, heavy units, better suited to industrial use than domestic.
I was just having an idle thought about how many ex-BT Mains Conditioners could be loaded into the bomb-bay of a Vulcan bomber and the damage they would create if dropped onto the average post-WWII battleship . . . :-\
I bought mine because I have a recurring issue with spikes on my upstream SNRM and I wanted to test if these were the result of mains spikes. I live in a rural area with rather dodgy mains supplies. I used it to supply power to my modem/router and network switch, and it made not a jot of difference. It's now packed away in a cupboard.
Ah, yes. You have mentioned your location in the past and I have taken in a Google street-view tour to look at the location one of the fibre cabinets.
-
You can even use a cheapo car battery jump starter pack which incorporates a 12V DC output socket and used this to power the HG612 close to 24 hours when testing if i had mains noise and the result was my mains was not the culprit.
-
I don't currently have a 12V battery and unfortunately 9V is too little for the HG612 :(
I'll see what I can find tomorrow.
-
As an example of a line where the BT conditioner makes a significant difference I attach my CRC over a few days with the conditioner. If I remove the conditioner the CRC spikes are about 4-5 times bigger and likewise, rather than 1-2 SES/day with it, I get about 6-10 without it. It is these CRC spikes that cause a number of modems to be unacceptable on my line. The ZyXEL 8324 in particular often lost sync when they occurred, even when speed capped to match my usual HG612 and its usual speed. An HG612 has been found best at coping with them.
-
@les-70 could you remind me what sort of line you're on?
-
Whilst I'm moving off topic for my own thread, which was about shielding, the mains-conditioner stuff is very welcome.
I'd be very grateful if people could do do some experiments. The Belkin PureAV, which has not been _scientifically_ tested by me, is available from loads of places, amazon.co.uk for example.
Earlier posts about battery chargers set me wondering...
Could I run some modems off a lead-acid battery (what sort), which is on constant maintenance trickle charge? Would that work?
-
A UPS would do quite nicely and would be useful anyway would it not?
-
@AlecR -clarification :- running modems off _DC_.
Running off a battery would mean zero harmonics and a very stiff PSU too. (Presumably a good thing?)
[btw the modems are already run (indirectly) off a UPS which synthesises AC mains. Because of paranoia about the alleged poor quality of UPS' synthesised AC output, there are multiple levels of mains filtering between UPS and modems.]
-
Let me know what you find as I'm looking to do a similar thing.
-
I think this (http://www.amazon.co.uk/HQ-Universal-Sealed-Rechargeable-Battery/dp/B0013A7XOC) would be suitable for a router and to charge it, this (http://www.amazon.co.uk/Blackspur-BB-JS206-12V-Trickle-Charger/dp/B003VS7VVE) would seem appropriate :)
-
I think this (http://www.amazon.co.uk/HQ-Universal-Sealed-Rechargeable-Battery/dp/B0013A7XOC) would be suitable . . .
Weaver has three lines bonded, so three modems and one FireBrick router would need to be battery powered. As for trickle-charging, sheddyian (http://forum.kitz.co.uk/index.php?action=profile;u=6488) might be able to advise about solar-powered charging of lead-acid batteries.
-
Don't forget that nothing will make any difference unless you have the sort of noise that they mitigate. A battery with no charging connection is a good test and if it makes no difference you can forget the fuss.
For longer term use any charging circuit may introduce noise and UPS 's vary a lot in their degree of mains isolation. I would guess that if the battery helps a BT conditioner might be next best -- just a guess based on its mode of mainly being an isolating transformer with a saturated core.
@Weaver a 500m line from a small town centre located CAB. The Victorian nature of the locality probably also does not help!
-
Weaver has three lines bonded, so three modems and one FireBrick router would need to be battery powered. As for trickle-charging, sheddyian (http://forum.kitz.co.uk/index.php?action=profile;u=6488) might be able to advise about solar-powered charging of lead-acid batteries.
I had been meaning to chip in to this thread, but time was against me :(
Previously (can someone find the thread?) I'd tried running my router off of a 12 volt drill battery, and compared the ADSL2+ results to running from mains. I wasn't suffering from any known interference problems at the time. I found there was no noticeable difference, even when isolating the router from ethernet and relying purely on wireless to check the stats.
Similarly, when I was suffering from REIN on my ADSL2+ connection, where the synch would drop and resynch much slower for hours at a time (and bit/tone allocation severely affected), running from an electrically isolated battery would not improve matters for me.
[This REIN interference is now, thankfully, gone, I still do not know where it came from though assumed it was an indirect neighbour with a noisy LCD second TV that was switched on a few times each week]
I am currently running a Raspberry Pi web server from two standard car batteries wired in parallel to give 12 volts but increased current/ length of service.
The batteries are charged from a 20 watt solar panel that I bought on ebay for about £30. If you're going this route, over-estimate the input current to charge the battery. It only needs a few overcast days for your supply to be on a knife edge. I've yet to run my setup through a full winter without giving a sneaky top-up by connecting a mains charger to the batteries because I was anxious.
That said, running a router purely on battery power, and isolating it from ethernet cables (which could carry mains interference from switches or other devices) is probably the best you'll get for connection quality. And in my experience, it made no difference from running everything off the mains.
Ian
-
A thread I've just found where I was trying out battery powered (and mains isolated) router setups on ADSL2+
http://forum.kitz.co.uk/index.php/topic,13111.msg254572.html#msg254572 (http://forum.kitz.co.uk/index.php/topic,13111.msg254572.html#msg254572)
Ian
-
@sheddyian -you're words of experience could very well end up saving me a lot of time faffing about to no purpose Sheddyian. Many thanks. :-)
It's amazing, no matter how nutty a plan I may come up with, it seems to me that there's a chance that some adventurous kitizen will have been there before me!
-
I've now hooked my Billion 8800NL up to a 12V battery and it is working fine.
(I may or may not have killed a router when the wires were accidentally put the wrong way round :o)
-
(I may or may not have killed a router when the wires were accidentally put the wrong way round :o)
D'oh! :doh: