Folded phone line can mess up DSL.

[Jeff Liebermann]

On Sun, 13 May 2018 03:27:18 -0400, micky <NONONOmisc07@bigfoot.com>
wrote:

In alt.comp.os.windows-10, on Fri, 11 May 2018 21:41:40 -0400, Jason
nobody@nowhere.com> wrote:

In article <jpccfdpqjrlaoibesg7jua0679jmd0cam3@4ax.com>,
NONONOmisc07@bigfoot.com says...
I go to the NIC and put a Y connector in it,

Are there DSL isolators in line where they should be? I
couldn't tell from your post.

No. And it worked fine after I took out the extra cable. That's the
point.

You also moved the extra cable and connectors, which makes me suspect
that an intermittent connection. It takes a minute or three for the
ADSL modem to sync after the carrier returns, which makes cause and
effect type of troubleshooting rather difficult. You could wiggle the
connetions and NOT see any change in the lights on the modem. If you
suspect a bad connection, drag out a roll of CAT5 cable, and plug it
directly into the phone line where it enters the house (MPOE). Also,
disconnect the rest of the house from that might be loading the line.
If that works, your problem is somewhere in your inside wiring. If
the speed, SNR, noise power, and channel levels improve drastically
when you disconnect the hour phone wiring, then you probably are
missing a microfilter, have a microfilter installed backwards, or have
a bad microfilter. Or maybe you need a better microfilter:
<http://802.11junk.com/jeffl/pics/dsl/slides/DSL-microfilters.html>
(4 inductors are better than 2).

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[NY]

"amdx" <nojunk@knology.net> wrote in message
newsdh7is$29m$1@dont-email.me...

You may have the clue in your response, "excess was coiled up"
A coil of wire makes an inductor. An inductor is an impedance to high
frequencies.

Would that apply so much to a two-core cable, where at any instant, a
current is flowing one way in one conductor (eg on the way to the appliance)
and the opposite way (on the return) in the other? Would the fact that there
are two conductors tend to reinforce or cancel the effect?

If you have a cable that is too long and don't want to cut it to shorten it,
what is the best way of arranging it so as to avoid/minimise inductance? Is
it better to arrange it in a zig-zag rather than loops?

 

[Tim]

"NY" <me@privacy.net> wrote in
news:v5OdnTChrerT3WDHnZ2dnUU78f_NnZ2d@brightview.co.uk:

"amdx" <nojunk@knology.net> wrote in message
newsdh7is$29m$1@dont-email.me...
You may have the clue in your response, "excess was coiled up"
A coil of wire makes an inductor. An inductor is an impedance to
high
frequencies.

Would that apply so much to a two-core cable, where at any instant, a
current is flowing one way in one conductor (eg on the way to the
appliance) and the opposite way (on the return) in the other? Would
the fact that there are two conductors tend to reinforce or cancel the
effect?

If you have a cable that is too long and don't want to cut it to
shorten it, what is the best way of arranging it so as to
avoid/minimise inductance? Is it better to arrange it in a zig-zag
rather than loops?

At the frequencies DSL works at, inductance is not an issue. More of an
issue is the fact that the wire was kinked. OP doesn't state how
severely, but any kink is going to disrupt the twist pattern, and thus
has the potential to interfere with transmission. The other factor is
that if the kink is severe enough, it can cause partial reflectance of
the signal in the reverse direction, potentially degradeing the signal to
some extent. Since the DSL signal can approach 4mhz at the high end, skin
effect is starting to enter the mix (barely, but there). This is going to
be more noticable in solid core wire, since the single conductor is
larger. In a stranded cable the multiple strands of smaller gauge will
tend to lessen any impact from skin effect. I am going to assume that the
wire is question is stranded as opposed to solid core conductors. In that
case it is entirely possible that one or more of the multiple strands
could actually have been broken by the kink, thus pretty much
guaranteeing some reflection of the signal, with attending degradation.

Granted, the effect of any of the conditions mentioned above will
probably be slight, but they will be additive. The ideal solution would
be to rewire the link to remove any excess wire. The only reason not to
would be that the connection is considered to be only temporary, and even
then I can make a case for not having any excess wire involved.

 

[Mike S]

On 5/17/2018 9:39 PM, Tim wrote:

"NY" <me@privacy.net> wrote in
news:v5OdnTChrerT3WDHnZ2dnUU78f_NnZ2d@brightview.co.uk:

"amdx" <nojunk@knology.net> wrote in message
newsdh7is$29m$1@dont-email.me...
You may have the clue in your response, "excess was coiled up"
A coil of wire makes an inductor. An inductor is an impedance to
high
frequencies.

Would that apply so much to a two-core cable, where at any instant, a
current is flowing one way in one conductor (eg on the way to the
appliance) and the opposite way (on the return) in the other? Would
the fact that there are two conductors tend to reinforce or cancel the
effect?

If you have a cable that is too long and don't want to cut it to
shorten it, what is the best way of arranging it so as to
avoid/minimise inductance? Is it better to arrange it in a zig-zag
rather than loops?


At the frequencies DSL works at, inductance is not an issue. More of an
issue is the fact that the wire was kinked. OP doesn't state how
severely, but any kink is going to disrupt the twist pattern, and thus
has the potential to interfere with transmission. The other factor is
that if the kink is severe enough, it can cause partial reflectance of
the signal in the reverse direction, potentially degradeing the signal to
some extent. Since the DSL signal can approach 4mhz at the high end, skin
effect is starting to enter the mix (barely, but there). This is going to
be more noticable in solid core wire, since the single conductor is
larger. In a stranded cable the multiple strands of smaller gauge will
tend to lessen any impact from skin effect. I am going to assume that the
wire is question is stranded as opposed to solid core conductors. In that
case it is entirely possible that one or more of the multiple strands
could actually have been broken by the kink, thus pretty much
guaranteeing some reflection of the signal, with attending degradation.

Granted, the effect of any of the conditions mentioned above will
probably be slight, but they will be additive. The ideal solution would
be to rewire the link to remove any excess wire. The only reason not to
would be that the connection is considered to be only temporary, and even
then I can make a case for not having any excess wire involved.

I agree with previous posters that a bad connector, or a severe kink,
sound like the most likely cause of the problem, in that order.

 

[whit3rd]

On Sunday, May 13, 2018 at 12:09:42 AM UTC-7, Tim wrote:

Jason <nobody@nowhere.com> wrote in
news:MPG.3561797466f945f99896a8@news.eternal-september.org:

In article <XnsA8E053B695DAtimothybilyahoocom@
69.16.179.28>, onelydad58@gmail.com says...
Having the wires coiled like that very likely degraded the line
electrical characteristics...

Why? Twisted pairs are resistant to interference.

Yes, twisted pairs are more resistant to interference, but the conductor
diameters, wire spacing, and insulation for CAT5 and CAT6 cables are very
carefully selected...

Part of that selection is that the pairs are twisted at different pitches, so
that coupling over a long length averages to zero. But if you're only using
one pair, as in a DSL connection, and you coil it, coil #1 can couple to coil #2
because the twist pitch is the same. DSL and ADSL etc. are good at making
sense of the signals, but not perfect.

The coupling of SIMILAR twisted pairs, if they are adjacent, is not minimal.