Do I need line filters?

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Earbanean

363 posts

Ultimate Geek

# 83034 9-May-2011 15:33

I have previously used ADSL line filters for non-ADSL equipment (phones, sky decoder) in my house. Now I have moved into a new house and in the study next to the phone jackpoint is another jackpoint with a sticker saying "ADSL" on it.

Does this mean that a central splitter has been installed for the house? If so, does that mean that I no longer need line filters on the phones, sky decoder etc?

If this is all the case, then I would also assume that I would connect my broadband modem directly to the ADSL jackpoint with no filter. However, the DSL port on the modem is the smaller RJ type (is that an RJ11?), but the jackpoint is the larger type (RJ45?). How should I connect these?

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3216 posts

Uber Geek

Subscriber

# 467172 9-May-2011 16:08

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.

nate

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# 467173 9-May-2011 16:09

If there are two sockets there, yes there is probably a master splitter in the house. You need an RJ11-Telephone jack cable. DSE or Warehouse are your best bet.

Earbanean

363 posts

Ultimate Geek

# 467179 9-May-2011 16:25

Thanks guys.

Checking the jack point, it is a trelephone style socket, so I guess the RJ11 to telephone plug cable is the way to go.

By the way, is there an easy way to confirm that the central splitter is there and working correctly? i.e. is there some sort of speed test, or noise test or something? Or is it just a case that the DSL modem won't work connected to the other jackpoints?

bnapi

92 posts

Master Geek
Inactive user

# 467198 9-May-2011 17:28

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?

CYaBro

3216 posts

Uber Geek

Subscriber

# 467209 9-May-2011 18:03

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?

Why would you want to do that?
A master splitter gives you the best connection and no need to use filters on all other devices.
If you have a monitored alarm then you can't remove it anyway.

CYaBro

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# 467212 9-May-2011 18:06

Earbanean: Thanks guys.

Checking the jack point, it is a trelephone style socket, so I guess the RJ11 to telephone plug cable is the way to go.

By the way, is there an easy way to confirm that the central splitter is there and working correctly? i.e. is there some sort of speed test, or noise test or something? Or is it just a case that the DSL modem won't work connected to the other jackpoints?

If it is a standard BT telephone socket then just use one of the filters you have to connect the ADSL router to it.
The ADSL side of the filter does nothing so bascially you will be using it as an adapter to change from the RJ-11 plug to the BT plug.

Earbanean

363 posts

Ultimate Geek

# 467388 10-May-2011 08:30

Roger that. Thanks for the info.

Ragnor

8035 posts

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# 467623 10-May-2011 16:17

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?

Wouldn't recommend removing the splitter, will increase interference and lower dsl line rate.

If the house is using star wiring instead of daisy chained it's not to hard to change which jack is the ADSL jack.

webwat

1990 posts

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# 468062 11-May-2011 21:13

Confirm the master splitter is working by plugging the modem into the non-adsl jackpoint. If it cannot get any ADSL signal then splitter is working properly by blocking ADSL from all but one outlet.

Qualified in business, certified in fibre, stuck in copper, have to keep going ^_^

bnapi

92 posts

Master Geek
Inactive user

# 468122 12-May-2011 01:01

CYaBro:
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?

Why would you want to do that?
A master splitter gives you the best connection and no need to use filters on all other devices.
If you have a monitored alarm then you can't remove it anyway.

Because the master splitter accepts the wireless router which may be far away so to remove the master splitter and instead use a filter right by the computer will mean a stronger signal. So can it be done?

sbiddle

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Biddle Corp

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# 468126 12-May-2011 06:19

bnapi:
CYaBro:
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?

Why would you want to do that?
A master splitter gives you the best connection and no need to use filters on all other devices.
If you have a monitored alarm then you can't remove it anyway.

Because the master splitter accepts the wireless router which may be far away so to remove the master splitter and instead use a filter right by the computer will mean a stronger signal. So can it be done?

Since you'll obviously need a tech to visit to remove it you'd be far better off getting the master filter rewired to another jackpoint. Statistically speaking removing it will reduce your ADSL speed, You'd be the first person I've ever come across you didn't want one - ideally there should be no such thing as plug in filters and all installs would be master filters, the fact so many people rely on plug in filters is why so many people have poor ADSL2+ speeds.

lostangel

163 posts

Master Geek

# 468128 12-May-2011 07:07

The fact a splitter is installed does not mean it is a 'master' splitter.
Please be aware that the splitter could be installed further along the internal line.

That is ....

Some other jacks could have adsl available. You can test by plugging your modem/router into the other jacks and seeing if you get any dsl signal.

As for shortening the line, yes this is a good idea if the adsl jack is a lot further away than another jack, however it's not normally of any severe impact.

Unless you are getting very poor sync rates, shortening the internal length will do little.

For example, in my sleepout, an extra 30 - 40 metres of cable from the houses jack, I lose around 300 kbps.
I am on the outer edge of a 10mbit zone so this change is not noticable in performance.

Beddhist

57 posts

Master Geek

# 468977 14-May-2011 06:24

CYaBro: ... plugging an RJ-11 plug into the RJ-45 socket will damage the outer pins.

Sorry to have to disagree with you here. When I was managing the IT cabling at Rotorua Hospital we often used RJ-11 patch cables in RJ-45 sockets. I have not seen a single damaged socket.

That is not to say that it can't be damaged. Obviously I was aware of what I was doing and taking some care to plug it in. I don't know whether users plugged in many of the phones themselves...

cyril7

7190 posts

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# 468993 14-May-2011 09:11

Only this week I was called to a site I had never been to before (large software development company based in ChCh and Welly) issues was some TOs that did not work, on investigation it became apparent that untill a recent move about in the office all the non working sockets had previously been assigned phone and RJ11's used, they had been that way for some years, upon examining the sockets they were clearly damaged the outer pins had with time pushed back and not returned when the plug was evenually removed.

You can get RJ11 plugs with slots in the shoulders of the plug to emulate the outer pin locations that prevent any damage, these I seem to remember are mandated under Telstra rules somewhere.

The issue is clearly time and specific socket pin design related, short or even modest time with an RJ11 inserted does not always cause the damage, till you find it does.

Regardless, in the OP's case as this socket is most likely only to be used for DSL dont worry about any damage as its only ever going to use pair1 (ie the inner pair). I normally install a RJ45 socket for central DSL filter installs, and just plug the RJ11-RJ11 line cord in to the modem.

Cyril

Earbanean

363 posts

Ultimate Geek

# 470106 17-May-2011 14:05

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.

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