ADSL fails on extension only - why?

(crossposted to two newsgroups as it's a bit borderline...)

I've been investigating a loss of DSL line sync for a friend. Changed
the router, filters, unplugged the other phones...etc.

Eventually found it worked OK in the master socket but not in the
extension.

Phone on the same extension is clear as a bell, no noise.

Clearly it looks as if I have to replace the extension wiring...but,
first, what could be a technical reason for this? Clearly the wires
aren't broken or the phone wouldn't work. High capacitance? but it's
still in parallel with the master socket when I'm testing from there.

I'm just a bit uneasy that I can't understand a reason. What am I
missing?
--
Bob Eager
rde at tavi.co.uk
PC Server 325*4; PS/2s 9585, 8595, 9595*2, 8580*3,
P70...

"Bob Eager" <(E-Mail Removed)> wrote in message
news:176uZD2KcidF-pn2-(E-Mail Removed)...
> (crossposted to two newsgroups as it's a bit borderline...)
>
> I've been investigating a loss of DSL line sync for a friend. Changed
> the router, filters, unplugged the other phones...etc.
>
> Eventually found it worked OK in the master socket but not in the
> extension.
>
> Phone on the same extension is clear as a bell, no noise.
>
> Clearly it looks as if I have to replace the extension wiring...but,
> first, what could be a technical reason for this? Clearly the wires
> aren't broken or the phone wouldn't work. High capacitance? but it's
> still in parallel with the master socket when I'm testing from there.
>
> I'm just a bit uneasy that I can't understand a reason. What am I
> missing?
> --
> Bob Eager
> rde at tavi.co.uk
> PC Server 325*4; PS/2s 9585, 8595, 9595*2, 8580*3,
> P70...
>
What type of master ? The NTE faceplates are filtered from then on for
hardwired. Is the cabling CW1308 or is it a DIY kit?
Do you hear a Hiss?
you dont need a filter unless ou have a phone plugged in so try without a
filter if you havent allready.

Other than that your guess is as good as mine.

Ian

www.bathford-broadband.co.uk
www.cyber-cottage.co.uk

On Mon, 10 Nov 2003 18:44:59 UTC, "Ian" <(E-Mail Removed)>
wrote:

> "Bob Eager" <(E-Mail Removed)> wrote in message
> news:176uZD2KcidF-pn2-(E-Mail Removed)...
> > (crossposted to two newsgroups as it's a bit borderline...)
> >
> > I've been investigating a loss of DSL line sync for a friend. Changed
> > the router, filters, unplugged the other phones...etc.
> >
> > Eventually found it worked OK in the master socket but not in the
> > extension.
> >
> > Phone on the same extension is clear as a bell, no noise.
> >
> > Clearly it looks as if I have to replace the extension wiring...but,
> > first, what could be a technical reason for this? Clearly the wires
> > aren't broken or the phone wouldn't work. High capacitance? but it's
> > still in parallel with the master socket when I'm testing from there.
> >
> > I'm just a bit uneasy that I can't understand a reason. What am I
> > missing?

> What type of master ? The NTE faceplates are filtered from then on for
> hardwired.

The NTE is unfiltered; Solwise filters on all extensions at socket
level.

> Is the cabling CW1308 or is it a DIY kit?

Lokks like original BT installation using external grade cable (most of
the extension runs outside the house, floor to floor).

> Do you hear a Hiss?

No

This is an installation that worked fine from May until about 3 weeks
ago. I would guess the cable has got damp, but I'm curious as to what
kind of falt would not affect a router plugged in at the NTE.

--
Bob Eager
rde at tavi.co.uk
PC Server 325*4; PS/2s 9585, 8595, 9595*2, 8580*3,
P70...

Bob Eager wrote:

> On Mon, 10 Nov 2003 18:44:59 UTC, "Ian" <(E-Mail Removed)>
> wrote:
>
>> "Bob Eager" <(E-Mail Removed)> wrote in message
>> news:176uZD2KcidF-pn2-(E-Mail Removed)...
>> > (crossposted to two newsgroups as it's a bit borderline...)
>> >
>> > I've been investigating a loss of DSL line sync for a friend. Changed
>> > the router, filters, unplugged the other phones...etc.
>> >
>> > Eventually found it worked OK in the master socket but not in the
>> > extension.
>> >
>> > Phone on the same extension is clear as a bell, no noise.
>> >
>> > Clearly it looks as if I have to replace the extension wiring...but,
>> > first, what could be a technical reason for this? Clearly the wires
>> > aren't broken or the phone wouldn't work. High capacitance? but it's
>> > still in parallel with the master socket when I'm testing from there.
>> >
>> > I'm just a bit uneasy that I can't understand a reason. What am I
>> > missing?
>
>> What type of master ? The NTE faceplates are filtered from then on for
>> hardwired.
>
> The NTE is unfiltered; Solwise filters on all extensions at socket
> level.
>
>> Is the cabling CW1308 or is it a DIY kit?
>
> Lokks like original BT installation using external grade cable (most of
> the extension runs outside the house, floor to floor).
>
>> Do you hear a Hiss?
>
> No
>
> This is an installation that worked fine from May until about 3 weeks
> ago. I would guess the cable has got damp, but I'm curious as to what
> kind of falt would not affect a router plugged in at the NTE.
>
Damp causes corrosion and copper oxide can act like a diode ,I have seen
this happen before .
--
Outgoings certified Microsoft free
Checked with Suse 9

"Ian G" <(E-Mail Removed)> wrote in message
news:bop0lc$ou3$1$(E-Mail Removed)...
> Bob Eager wrote:
>
> > On Mon, 10 Nov 2003 18:44:59 UTC, "Ian" <(E-Mail Removed)>
> > wrote:
> >
> >> "Bob Eager" <(E-Mail Removed)> wrote in message
> >> news:176uZD2KcidF-pn2-(E-Mail Removed)...
> >> > (crossposted to two newsgroups as it's a bit borderline...)
> >> >
> >> > I've been investigating a loss of DSL line sync for a friend. Changed
> >> > the router, filters, unplugged the other phones...etc.
> >> >
> >> > Eventually found it worked OK in the master socket but not in the
> >> > extension.
> >> >
> >> > Phone on the same extension is clear as a bell, no noise.
> >> >
> >> > Clearly it looks as if I have to replace the extension wiring...but,
> >> > first, what could be a technical reason for this? Clearly the wires
> >> > aren't broken or the phone wouldn't work. High capacitance? but it's
> >> > still in parallel with the master socket when I'm testing from there.
> >> >
> >> > I'm just a bit uneasy that I can't understand a reason. What am I
> >> > missing?
> >
> >> What type of master ? The NTE faceplates are filtered from then on for
> >> hardwired.
> >
> > The NTE is unfiltered; Solwise filters on all extensions at socket
> > level.
> >
> >> Is the cabling CW1308 or is it a DIY kit?
> >
> > Lokks like original BT installation using external grade cable (most of
> > the extension runs outside the house, floor to floor).
> >
> >> Do you hear a Hiss?
> >
> > No
> >
> > This is an installation that worked fine from May until about 3 weeks
> > ago. I would guess the cable has got damp, but I'm curious as to what
> > kind of falt would not affect a router plugged in at the NTE.
> >
> Damp causes corrosion and copper oxide can act like a diode ,I have seen
> this happen before .
> --
Ah but I would expect ring trip then.
I would try it without a filter As i would expect soem hiss.

Ian


> Outgoings certified Microsoft free
> Checked with Suse 9

On Mon, 10 Nov 2003 21:41:00 UTC, Ian G <(E-Mail Removed)>
wrote:

> > This is an installation that worked fine from May until about 3 weeks
> > ago. I would guess the cable has got damp, but I'm curious as to what
> > kind of falt would not affect a router plugged in at the NTE.
> >
> Damp causes corrosion and copper oxide can act like a diode ,I have seen
> this happen before .

Yes, fair enough. I had thought of something like that.

But, in that case the diode is 'across' the cable. So, it should have an
effect whether I am using an extension socket or the master socket
(since they are wired in parallel).

I can't yet explain what I am seeing, and it worries me because it means
the solution may not be correct....!
--
Bob Eager
rde at tavi.co.uk
PC Server 325*4; PS/2s 9585, 8595, 9595*2, 8580*3,
P70...

On 10 Nov 2003 20:36:09 GMT, "Bob Eager" <(E-Mail Removed)> wrote:



>This is an installation that worked fine from May until about 3 weeks
>ago. I would guess the cable has got damp, but I'm curious as to what
>kind of falt would not affect a router plugged in at the NTE.

ADSL tends to stay working long after voice has died, I've known it
work with only one wire left! The wire would be the last thing on
the list to check. Are you sure the socket wiring is correct though?
Try using a pair on only 2 and 5 at each end, with this any phone
connected may not ring but should still dial out and if used to
answer a call will still work. In this configuration does ADSL work?
If not try another pair in the cable to 2 and 5 at both ends.


--
Peter Parry WPP Ltd http://www.wpp.ltd.uk
Antenna solutions for car, caravan, house, office, boat and tent.
Fixed Telephone wiring guide at :-
http://www.wppltd.demon.co.uk/WPP/Wi...telephone.html

On Mon, 10 Nov 2003 23:29:42 UTC, Peter Parry <(E-Mail Removed)> wrote:

> ADSL tends to stay working long after voice has died, I've known it
> work with only one wire left! The wire would be the last thing on
> the list to check. Are you sure the socket wiring is correct though?
> Try using a pair on only 2 and 5 at each end, with this any phone
> connected may not ring but should still dial out and if used to
> answer a call will still work. In this configuration does ADSL work?
> If not try another pair in the cable to 2 and 5 at both ends.

The wiring is correct. Remember it's been working since last spring. I'm
just trying to work out what kind of cable fault would:

a) Work with voice
b) Not work with ADSL
c) Allow the master socket to work without disconnecting the faulty
extension

--
Bob Eager
rde at tavi.co.uk
PC Server 325*4; PS/2s 9585, 8595, 9595*2, 8580*3,
P70...

On 10 Nov 2003 23:43:15 GMT, "Bob Eager" <(E-Mail Removed)> wrote:

>I'm
>just trying to work out what kind of cable fault would:
>
>a) Work with voice
>b) Not work with ADSL
>c) Allow the master socket to work without disconnecting the faulty
>extension

high attenuation of the extension wiring at higher frequencies would
be a logical conclusion. A dodgy joint (corrosion ?) perhaps or poor
IDC connection.

Interfernce local to the extension socket might be another
possibility, so the SNR is too low even though the attenuation is low
downstairs.

I have an ADSL filter that won't allow ADSL to work but will allow a
phone to work off it, I guess its a dud.

I assume your testing off the master socket is off the faceplate and
not off the backplate socket which disconnects the extension wiring.

Phil

In article <176uZD2KcidF-pn2-(E-Mail Removed)>, Bob Eager
wrote:
> The wiring is correct. Remember it's been working since last spring. I'm
> just trying to work out what kind of cable fault would:
>
> a) Work with voice
> b) Not work with ADSL
> c) Allow the master socket to work without disconnecting the faulty
> extension

Series resistance and parallel capacitance would form a crude low pass
filter which could have the effect you describe. Provided the resistance
was significantly higher than the impedance of the incoming feed at the
master socket, then it would have little effect on equipment connected at
the master socket.

Have you tried disconnecting the extension cable and making any electrical
measurements of it? If so, what did you measure and what did you find?

You stated earlier that the system was working until about 3 weeks ago. Did
you change anything else significant at that time? Any building or DIY work
that might have crushed a cable, for instance? Any spillage that could have
got at the wires? Any installation of other electrical equipment that
includes wiring close to the extension wiring? Any installation of
equipment that could radiate RF signals? If your ADSL equipment or the
extension cable is close to a party wall, did your neighbour make any
wiring changes or install any equipment 3 weeks ago?

Rod.