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avzone
10-25-2007, 02:35 PM
The Cable Dresser (http://www.cabledresser.com/)

tschulte
10-25-2007, 03:00 PM
I think we have already discussed this here. Or was that at RC?

Matt
10-25-2007, 03:20 PM
I think we have already discussed this here. Or was that at RC?

It was here about 6 months ago. Thanks for the old news Graham. ;) :p :D

avzone
10-25-2007, 06:33 PM
It was here about 6 months ago. Thanks for the old news Graham. ;) :p :DAre you sure you're not confusing it with the Cable Comb (http://www.acomtools.com/)? I did a search before posting it since I've been away for awhile.

If not...I knew that. I just thought you could use a reminder.;)

flcusat
10-25-2007, 06:34 PM
I think the other one was different. This one is only good for CAT5 % 6 cables.

vette84
10-25-2007, 11:57 PM
I originally posted about the cable comb, and am now intrigued by an article in my Cabling Installation & Maintenance mag that showed up earlier this week. The pertinent excerpt follows...




Cable combing--Combing the cable installation-installing or laying the cables in a tray neatly, side by side-is a practice not addressed in specifications yet, but may soon be. It is, without question, a technical-performance concern. In long runs of several cables, it is customary to install the runs in an orderly, straight, and side-by-side manner. This technique provides a very neat and professional appearance; however, particularly at very high data rates, it also allows the inductive reactance coupling of electric fields surrounding the conductors to more easily combine and build up, and the capacitive reactance coupling between the conductors to further minimize. The main concern is not totally between the four pairs in a given cable, but the cable-to-cable coupling directly affecting alien crosstalk. By using a random lay, the cables are constantly changing their relative spacing and crossover position. This reduces the chances for a long exposure to inductive and capacitive coupling. In fact, coupling fields can actually experience some cancellation as they wander in a random fashion along the cable tray or rack.
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While aesthetically pleasing, neatly combed bundles are proving detrimental to cable performance. Randomly laid cables may not look pretty, but yield better results. Even if you have followed the installation specifications perfectly, it is more difficult to get good BERs at high data rates than at lower rates. (Please note that the following formulas only illustrate relationships, and should not be used for actual circuit calculations). Critical factors are inductive and capacitive reactance.
Remember that inductance is constant along the conductor; however, the higher the signal data rate, or frequency, the greater the reactance, or current-inhibiting effect, or inductive reactance XL. As the data rate, frequency, or inductance increases, XL also increases.
This can be expressed mathematically with the following formula: XL=2ΠfL. 2Π is a constant with a value of 6.28; f is the data rate or frequency; and L is the inductance of the pair or other component at a given point in the circuit.
XL exists even in all good circuits, but its effect is made worse by problems with too-tight bends, kinks and, to some extent, with staples and tie wraps.
Capacitance is also constant along the conductors. But in this case, the capacitive resistance, XC, in contrast to XL, decreases as the signal data rate increases. So, with a smaller XC, or opposing effect to signal coupling, crosstalk can increase as the data rate, or frequency, increases.
This also can be expressed: XC = 1/2ΠfC. 2Π is the constant 6.28; f is the data rate or frequency; and C is the capacitance between the pairs or other components at a given point in the circuit.
Like XL, XC is a factor in well-established circuits, but its effect can easily be made worse by problems with crushing, twisting, bends that bring the conductors closer together, and long installation runs of combed cable.
The resistance effect also increases with higher data rates, although it is not quite as contributory as is inductive reactance. The increasing effect is due to the way the higher-frequency energy propagates along a conductor-a condition called skin effect. Also of importance is the chemical composition of the insulating materials, which affects the impedance characteristic of an insulated conductor. Higher frequencies are attenuated more so than the lower ones. This effect is related to the insulation dielectric constant. (Please note that when discussing signal transmission, most specifications and other literature refer to resistance factor as attenuation.)

Matt
10-26-2007, 12:00 AM
Very interesting.

djnorm
10-26-2007, 06:02 AM
Honestly, I wouldn't have thought of using that tool except for the last ten feet going into the rack...

flcusat
10-26-2007, 02:11 PM
Does anybody know if the Cable Comb is good for any cable other than CAT5/6?

fluid-druid
10-27-2007, 01:04 AM
I've never used either tool... but in the video on the site posted in this thread, the cables ALREADY look pretty neatly combed before he puts the tool on.

What happens when cables are "woven" or otherwise tangled? I can't see that tool saving much time... but I'd like to try one once.

Pilgrim
10-27-2007, 02:47 AM
I've never used either tool... but in the video on the site posted in this thread, the cables ALREADY look pretty neatly combed before he puts the tool on.

What happens when cables are "woven" or otherwise tangled? I can't see that tool saving much time... but I'd like to try one once.

Given cat 5's tendency to tangle on itself if extended more than a foot or two, I would have to see it, and try it,to beileve it.

It is possible that I have been too gentle on the cables in the past...:cool:

vette84
10-27-2007, 11:06 AM
Does anybody know if the Cable Comb is good for any cable other than CAT5/6?

The openings in either tool is .25", which should be good for everything except Quad RG6, of which the Liberty we use is .287".