Do I need line filters?

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webwat

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#470230 17-May-2011 19:41

Earbanean: I checked the modem at the other sockets and the ADSL indicator on the modem flashed, but never went solid. So it looks like filter is on the other lines.

I just went for an RJ11 to BT cable for the modem to socket to keep things tidy - and it all works fine.

Thanks for the help.

Thats not tidy. You can fix it by chopping the BT plug and putting an RJ45 on that fits the socket. I could send you one for about $6 but you should be able to find an RJ11 cable that works fine since you probably only ever have a modem plugged into it.

Maybe you can make new outlets that go from the modem to the place you want the wifi router, and run cable under the house for it. Or if the wiring to the BT jacks uses 4-pair cable, then just connect up the orange and green pairs to those new RJ45 outlets.

Time to find a new industry!

Earbanean

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#470512 18-May-2011 13:54

I'm not sure I understand that. The ADSL socket is a BT style socket and the modem is an RJ11. Therefore, the RJ11 to BT cable seems the best bet to me.

Maybe there is confusion, because in my first post, I said that the socket was RJ45 (with a "?"). However, after checking when I was home, I clarified in a later post that it was in fact BT.

shk292

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#472097 22-May-2011 10:24

bnapi:
CYaBro: That's sounds right.
If a jack point is labelled ADSL then you can assume that there is a master splitter installed and the ADSL won't work on any other jack point as they have been filtered out at the point of entry to the house.
If the ADSL jackpoint is an RJ45 one as you suspect (not a normal BT telephone socket) then you will be best to get an RJ-11 to RJ-45 cable as plugging an RJ-11 plug into the RJ-45 socket will damage the outer pins.

can a master splitter be removed and all other jackpoints in the house accept adsl again?

My house is wired with a master splitter, but I wanted to install the modem in a different room (there are sockets everywhere). It turned out - and speaking to a friend who used to do house wiring, this is atandard practice - one pair of the phone cable's four wires is connected to the ADSL side of the splitter, and the other pair is connected to the unfiltered (phone) side. Therefore, if you want to use a different socket for your modem, it's a simpe job to change the pair of wires connected to the socket. Might be worth putting an AVO on that pair and checking there are no high voltages when the phone rings, because I understand that in the old days, this second pair provided the high voltage for ringing the bell (which modern phones don't need).

sbiddle

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#472135 22-May-2011 10:44

shk292:
bnapi:
CYaBro: That's sounds right.
If a jack point is labelled ADSL then you can assume that there is a master splitter installed and the ADSL won't work on any other jack point as they have been filtered out at the point of entry to the house.
If the ADSL jackpoint is an RJ45 one as you suspect (not a normal BT telephone socket) then you will be best to get an RJ-11 to RJ-45 cable as plugging an RJ-11 plug into the RJ-45 socket will damage the outer pins.

can a master splitter be removed and all other jackpoints in the house accept adsl again?

My house is wired with a master splitter, but I wanted to install the modem in a different room (there are sockets everywhere). It turned out - and speaking to a friend who used to do house wiring, this is atandard practice - one pair of the phone cable's four wires is connected to the ADSL side of the splitter, and the other pair is connected to the unfiltered (phone) side. Therefore, if you want to use a different socket for your modem, it's a simpe job to change the pair of wires connected to the socket. Might be worth putting an AVO on that pair and checking there are no high voltages when the phone rings, because I understand that in the old days, this second pair provided the high voltage for ringing the bell (which modern phones don't need).

It's not quite so simple. The DSL output from the splitter should be a dedicated cable that only runs to a single jackpoint. Sounds like your install the DSL output was looped around the house following the existing series wiring with scotchloks at each jackpoint. If so it's certainly a poor instllation and not recommended.

By second pair I assume you also mean the 'ring' wire which was the 3rd wire used in the old master jackpoints. Two wires came into the jackpoint and 3 wires out which then lead to the extension jackpoints.

cyril7

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#472198 22-May-2011 11:20

The DSL signal cannot be treated as you would with a voice signal, at voice frequencies and cable lengths involved the cable does not behave like a true transmission line at higher RF frequencies as used by DSL. Therefore its acceptable to essentially have taps all over the place for the voice service.

For DSL service however you must treat the line as a RF transmission line, as such to introduce taps will cause loss of parts of the DSL band as a result of echos from the unused line in the house.

As steve says it is infact not standard practice to have the DSL circuit available at many outlets around the house, if this is the case then you have been mis informed. The DSL circuit can and often does share the 2nd pair in the sheath with the voice service, but should only terminate on a single socket and once their MUST NOT continue on to other sockets (regardless of it a device is connected to that furhter socket or not).

I will re iterate, a proper DSL master filter installation will have the DSL pair go from the input of the DSL filter (or DSL port of the master filter if a VDSL2 rated one) via a dedicated pair within the house wiring or dedicated cable to a dedicated socket and terminate there, anything else is incorrect.

Edit, also if you are wanting to get a 2nd pair out of an old 3pair phone cable system, ensure you do infact get a pair and not split one, red/white, orange/black and blue/green are the three pairs, if you unsheath a 100mm length you should find each of those kind of stay twisted together. If you put DSL down a split pair it will not work correctly, or never achieve full performance.

Cheers
Cyril

shk292

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#472204 22-May-2011 11:26

cyril7: The DSL signal cannot be treated as you would with a voice signal, at voice frequencies and cable lengths involved the cable does not behave like a true transmission line at higher RF frequencies as used by DSL. Therefore its acceptable to essentially have taps all over the place for the voice service.

For DSL service however you must treat the line as a RF transmission line, as such to introduce taps will cause loss of parts of the DSL band as a result of echos from the unused line in the house.

As steve says it is infact not standard practice to have the DSL circuit available at many outlets around the house, if this is the case then you have been mis informed. The DSL circuit can and often does share the 2nd pair in the sheath with the voice service, but should only terminate on a single socket and once their MUST NOT continue on to other sockets (regardless of it a device is connected to that furhter socket or not).

I will re iterate, a proper DSL master filter installation will have the DSL pair go from the input of the DSL filter (or DSL port of the master filter if a VDSL2 rated one) via a dedicated pair within the house wiring or dedicated cable to a dedicated socket and terminate there, anything else is incorrect.

Cheers
Cyril

Interesting to hear it's not best practice. It seems to work in the case of my house, with the socket I've used quite a distance from the 'master' DSL one.
Obviously not the way to wire a house, based on posts above - but might be worth the OP trying this in case that's how his house is wired anyway.

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cyril7

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#472213 22-May-2011 11:33

Hi, yes incorrect wiring may work, just the results will be non optimal and unpredicatable, the only correct solution to avoid issues and get full performance is as described.

Cheers
Cyril

webwat

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#472348 22-May-2011 14:22

cyril7: Hi, yes incorrect wiring may work, just the results will be non optimal and unpredicatable, the only correct solution to avoid issues and get full performance is as described.

Cheers
Cyril

Otherwise a future internet user will call up the provider and complain about speed or whatever, and often deny any possibility that house wiring could be an issue because "it worked before, nothings changed". Unfortunately problems with picking up noise or bad connections at all those joins aren't always obvious while you are testing it. However if you absolutely must share the daisychain cabling and if its Cat5 cable, then only join the link you need because the DSL service is point-to-point.

But really, doesnt the wifi get any signal in your living room already? Try running ethernet to your wifi point instead of putting the DSL modem there.

Time to find a new industry!

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