lecky cable near phone socket
This is a discussion on lecky cable near phone socket within the Cabling and faceplate help forums, part of the Sky Broadband help and support category; Hi, I would like to move my Master socket to the other side of my front door. the drop cable ...
- 07-12-06, 02:40 PM #1
lecky cable near phone socket
I would like to move my Master socket to the other side of my front door. the drop cable is not attatched to anything at the moment it just trails down the left hand side of the front door then goes into the master socket.
I would like to move it to the right hand side of the door as thats where my computer is, and this way will give me the neatest end result.
however, there is a mains electric cable and the main fuse box very close to where i want to put it.
can anyone tell me if this is likely to cause any problems (interference etc)
- 07-12-06, 03:18 PM #2
obviously this is just a hyperthetical question as moving anything behind the face plate is an offence which can lead to prosecution unless the work is carried out by bt.
Now thats out of the way, I cannot answer the question fully, however my master socket is located right next to my fuse box and my attenuation seems about right from my distance to the exchange. If its any help I have a filtered face plate and I run some shielded cat 5 cable up through the ceiling running alongside a big thick power cable that feeds my electric shower. Also my noise is okay as well, I am on a 6db profile, but I use the dmt tool (speedtouch router) and have it set to about 2db and do not suffer dropouts from the exchange.
So basically what I am saying is, you will still get your connection and I dont think your sync speed would be affected.
- 07-12-06, 03:49 PM #3
Maybe I could clear up a bit of confusion here?
Phone wires are really quite prone to electrical interference (in fact all sorts of emr including rf). This doesn't matter too much for voice calls but it can make a big impact on an ADSL signal.
It is not attenuation you need to worry about. Attenuation is a measure of the loss in power of electromagnetic signals between transmission and reception points. Many factors affect attenuation but by far the largest factor is line length. In simple terms, the further you are away from the exchange the higher your attenuation figure will be as the signal loss increases.
However you do need to worry about noise. You should try and keep the maximum separation possible between electrical wires/fuseboxes and anything to do with your ADSL connection. If you have to have them close then try for at least a 5cm gap (more for the fusebox).
- 07-12-06, 04:24 PM #4
Saturday, I largely agree with what you are saying but there are some things I dont agree with based on my own personal experience.
I agree that attenuation is mainly down to the length and quality of the line to the exchange, however other things can affect attenuation. In my case I switched to a filtered faceplate from adslnation, my attenuation dropped from 45 to 43 so based on my experience I would imagine there is a possibility that electrical interference can affect it although I would say not by a huge amount.(whether or not my old faceplace suffered from electrical intereference I do not know maybe it was just old - 7years)
Again from my own personal I have no ill effects of running a cat 5 cable directly alongside a power cable (permanently live and thick enough to support a 12kw shower), although as mentioned this is a quality shielded cable that I have and I would imagine on unshielded cable you would see some effect on noise but as I havent used unshielded I cannot give an honest answer on that.
FWIW tere is a relatively simple way of checking for electrical intereference by using a portable am radio. Tune this into a quiet frequency so that it is easier to pick up noise. You can then hold the radio close to where you are going to be running cables etc and if there is any intereference you will get an increase in the static / buzzing
So in a snapshot, if you do have the box moved, then use the best shielded cable that you can, as in my own experince of being next to a fusebox and main cable(s) etc I have not suffered at all
- 07-12-06, 04:57 PM #5
Hi, and thanks for the replies, i currently have an attenuation that suggests im about 3.4km from my exchange, but im only 1km from the exchange. the bloke i bought the house from was into diy, but he was chuffin useless, im going round repairing the disaster he left behind, you should see the number of rawl plugs in the bathroom walls
Anyway, the wires at the master socket need reseating as it looks like he used a spoon to get them in do you think this could explain my high attenuation ?
i was hoping to reseat the wires, fit a new faceplate and put the router next to the socket on the right hand side of the door, i could get away with leaving it where it is if i have to it just wont look as neat.
- 07-12-06, 05:04 PM #6
We're all allowed an opinion
The frequency of the signal being measured will change the apparent attenuation of a line and you must remember in the case you cite, you are using a router to measure attenuation. The router is interested in bandwidth. The less noise you have on a line the greater the bandwidth available to ADSL and the lower the apparent attenuation.
That's why when you fitted your filtered faceplate you saw a small change in attenuation as reported by the router. You had reduced noise when compared to your ordinary faceplate.
If you have to run a cable alongside an electrical cable then cat5e is about as good a choice as you can make. It has minimal shielding and the benefit is due to the cable twist configuration. It is still prone to electrical interference though. However, the poster was referring to a normal twisted pair - big difference.
A portable AM radio is a reasonable way of detecting rf noise which is one small part of the em spectrum. You're right though because rf noise is a particular problem for ADSL.
To know whether your connection has suffered from being next to a fusebox and a power cable you would of course have to run a comparison without those being present.
No. Your attenuation is due to your line length influenced a little by the amount of noise on the line.
- 07-12-06, 05:15 PM #7
Thanks for the clarrification, if i could ask another completely hypothetical question though.
say someone had messed about with the bt master socket then burried it under a laminated floor after running 1 el-cheapo (probably poundland knowing him) cable to a 8 way terminal block then split the signal 3 ways to 3 different el cheapo extension sockets (which hypotheticaly is all i have) would/could this give a falsly high attenuation ?
ps, the reason i would know this hypothetical situation is i know the hypothetical "diy"er quite well
- 07-12-06, 07:15 PM #8
Putting noise into the line might have pushed it up by 2 or 3db. An easy way to check would be to temporarily disconnect the extension cable to the master socket, connect directly and see what the difference is?
- 07-12-06, 07:30 PM #9
Electrical inteference from power cables can have serious consequences on a DSL line speaking from experience.
As a network admin. I recently dealt with an issue at one of our branches where the DSL line was intermittently dropping in the morning and late afternoon. This was a total loss in connectivity. BT visited the site - probably on six or seven occassions and our WAN providor replaced the routers, filters, etc.
Someone mentioned, in passing conversation that the fuse box was in the same cabinet as the BT box. It was'nt until our PBX maintainer attended site and replaced the cable with shielded CAT5 that the problem went away.
The drops were likely to be attributable to staff switching things on in the morning and switching off when they left the office.
- 07-12-06, 08:39 PM #10
If I were in your shoes i would fit a brand new NTE5, recover all internal wiring/sockets and renew the extensions that you need.