David_Dickson

Im installing a pc in a building away from the main complex here.
Ive run an 8-core cable underground, protected in a proper tube, to the building.
Fitted the rj45 plugs, plugged one end into my modem and the other to the pc.
It doesnt work for ****.
It connects to the net, but its so slow, it makes dial-up look space-age.
If i take the pc into my house and connect it to the modem with a normal length lead, it works fine.

I have checked the cable with a multimeter and there are no breaks or shorts between the wires.

The total cable length is about 25 meters.

please point out whatever stupid mistake I have made

apalmer

iTrader: (8)

m8

are you running UTP cable or STP cable, plus running near powerlines? Or magnetic interference?

David_Dickson

um, pass. Whats the difference?
Its not near any other power cables etc.

apalmer

iTrader: (8)

STP is sheilded twisted pair cable, utp unsheilded........


essentially the cable is less likely to pick attentuation or signal interference from electrical sources or magnetics. To be honest unless you asked for STP you wouldn't have got it so...


Hmmm strange one, i would be inclined to make a new piece of cable up from a reel or even run the cable direct not throurgh the ground if possible to make sure that cable is OK above ground! Possible to give that a go?

David_Dickson

gah, i have no more cable left. It is unshielded stuff I have used.
Ill get another length and try it, just running it direct temporarily to see whats what, and if that works, I will put it through the underground tube.
Fortunately, I had the foresight to bury a decent sized conduit and leave a wire in it to pull other cables through, so at least I dont have to dig up the garden again.

Dazza's-STi

You worry me when you say you've fitted RJ45's... firstly ya don't fit RJ45's to CAT5 cable, patchleads yes cable err, no... get a propper modular (Mod) jack and a backbox and terminate the cable you're run on the back of that, same other end and then use patch leads from your sockety... doing it the other way is just plain nasty.... I've seen some small businesses do this and also so called cable installers (sparkies) who've no idea what there doing... so although it does work its a crap way of doing it... this is most likely your problem...
daz

mykp

just a question how did you join them up and did you connect them correctly

they should be like this

Ethernet Cable: Color Coding Standard

568B is the standard

depending on the modem try a cross over.

TBH unless you have a cable tester even if you think the ends are crimped they might not be.

BlkKnight

did you use patch cable (stranded) or solid cable?

apalmer

iTrader: (8)

Actually thats exactly what cat5 cable is for whether a snagless patchlead or trunking copper agreed the casings are different but the internals are the same. 4 twsited pair copper cables. In an office you would terminate to a faceplate and trunk to a patch panel but rj45 ends are an interface standard so definately ok to use for ethernet cables in fact they are the only socket you can use for ethernet to my knowledge? Similar to RJ11 for modem connections

apalmer

iTrader: (8)

also as blkknight said, the internal copper is stranded on patch cables but they are still cat5/e certified OK. A difference only really appreciated in the comms room or above a dusty ceiling

BlkKnight

I thought stranded stuff was not as good over longer distance?

apalmer

iTrader: (8)

yeah there is a difference in the total length between the soft core stuff and trunking cable, i think 25 meters should b OK i know that there is a standard that says they should run a lot smaller than that but in practice i've made loads of cables (fly leads) to desks for devices to use up to and around that length with patch grade cable. Standard copper good for around 90 -100 meters.