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Mike S[_4_] Mike S[_4_] is offline
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Default Folded phone line can mess up DSL.

On 5/17/2018 9:39 PM, Tim wrote:
"NY" wrote in
o.uk:

"amdx" wrote in message
news
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.