DSL wiring question... 1

[gap48869]

By twisting the wires of CAT5e together as shown in the figure solids to solids, stripes to stripes you add copper to the circuit along with some added shielding. So my question is; what will be the effect of this wiring technique on a DSL connection?? will it improve the line quality?? will it create an unnecessary loop that can add noise to the circuit ??

PS: this wire will be running from the NID to a house (~40 meters)

 

[gap48869]

--picture--

 

[gap48869]

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[G0AOZ]

First off, I cannot get any of your links to work. The first one comes up with a BINGO ad, which I need like a hole in the head...

The individual wires within Cat5e are deliberately twisted in pairs. The twist is of a different length for each of the four pairs. The twist creates a balanced feed which helps reduce interference, electrical noise etc.

Inasmuch as electrical noise is reduced, this will help to improve the Signal-to-Noise ratio (or noise margin) of the received DSL signal.

A distance of 40m plus is nothing compared the the line length from the telephone exchange. Are you saying you're using Cat5e to carry the DSL signal 40m plus, or is this a LAN? Either way, should be a problem...

ROGER - G0AOZ.

 

[G0AOZ]

Sorry, last para should read... "Either way, should NOT be a problem...

ROGER - G0AOZ.

 

[gap48869]

@ G0AOZ

I'm using the cable to carry the DSL signal from the NID to the splitter, when I tested my connection directly from the NID I got 20% increase in connection speed, So there is definitely something wrong in the wiring, Its not logical to loose less than 5% of connection quality on a 3 kilometers line from the telephone exchange to the NID and a ridiculous 20% over a 40 meters line from the NID to the splitter!! So I'm changing the wiring now...

I read somewhere that Cat5e has a range of 100m, so a 40m Cat5e should carry a DSL signal on one of the pairs without worrying about loosing the signal strength. (??)

Quote:"The twist is of a different length for each of the four pairs"
So will the signal quality be relative to what pair I choose to work on? So for example if I connected the blue pair, will I get the same results if I have connected the yellow pair?

One more question: As you already said,the twists in the Cat5e are made to reduce the electrical noise; But if I use the wiring method from my first post, will it disable the noise reduction property of the Cat5e??

Thank you for the reply, and try this link -

http://www.box.net/shared/s83arbbiik

- to see the picture I uploaded.

 

[G0AOZ]

Ok, can see the page now, tried another browser...

Yes, 100m is the suggested limit for Cat5e, and you will of course still get some attenuation of the signal when running through this length. Although Cat5e is supposed to conform to certain standards, I believe that some "low quality" cables can if fact attenuate signals far more than others.

Whilst joining all the "solids" and the "stripes" to form a single pair might reduce the overall resistance end to end, doing this alters the characteristics of the cable in terms of inductance, capacitance, etc. These characteristics are carefully chosen to give best overall performance taking into account signal loss and electrical noise.

There is only a relatively small difference between the twists on the four pairs of wires - that difference being so small it can generally be ignored. So choosing a different pair ought to make no difference.

I'd say you would probably partially, if not fully destroy the balance of the cable by joining the individual wires together as you have indicated. (The twists also help to eliminate crosstalk, not that you're likely to suffer any from the way you're using this cable). I'd stick to a single pair, and make sure the connections at both ends are good, solid electrical joints.

ROGER - G0AOZ.

 

[gap48869]

Thank you so much ROGER (G0AOZ), your posts are AMAZING. I'll change the wiring next week and I'll be using a single pair. I'll post the results as soon as possible.

Thanks again, you were a great help!!