Technical
BULLETIN
  The Effect of Optimum Structural Stability on the Electrical Performance of MediaTwist® UTP Cable
TB-63

MediaTwist® is the

only UTP cable

manufactured

intentionally to

achieve both

conductor-to-conductor

and pair-to-pair

stability. The major

after-installation

advantages are

additional

headroom plus

exceptional return

loss, crosstalk,

power sum

crosstalk and

emissions/radiation

characteristics.

For More Information:

Belden
P.O. Box 1980
Richmond, IN 47375
765/983-5200

http://www.belden.com

© Copyright 1996, Belden Inc.

  Major improvements in unshielded twisted pair (UTP) technology have taken place in the last decade. Data rates have also progressed from 19.2 kbps to 155 mbps and beyond. But despite these seemingly substantial gains, many cable manufacturers have neglected to consider the performance losses that can be experienced when the structural integrity of the cable is compromised during installation.

End-users have long known the negative effects of improperly untwisting a pair at the termination point. The effects on crosstalk can be significant. Even a properly terminated cable can experience a several dB degradation in crosstalk performance. And they are also aware that as the frequency increases, so does the negative impact. (Even though the cable's electrical performance above 100 MHz cannot be documented due to the limitations of hand-held testers.)

The ideal UTP cable should therefore be structurally stable -- even after its installation. And topping the list of construction features that provide desired cable consistency and stability are uniform pair-to-pair separation, stable conductor-to-conductor spacing, and uniform twisting of the pairs.

Locking in Structural Stability

Belden's introduction of DataTwist® 350 was a step in the right direction toward a consistently stable UTP cable. By bonding the insulated conductors of a pair, Belden ensured the end-user of improved electrical consistency both before and after the installation process.

Now Belden has taken consistency one step further. Belden has produced MediaTwist®, a new UTP cable that not only ensures stable conductor-to-conductor consistency, but pair-to-pair stability as well. Belden's new design actually locks each of the four twisted pairs in its own individual chamber. So no matter how the cable is twisted or bent, pair location is uniform. This has major advantages with regards to return loss characteristics, crosstalk, power sum crosstalk, and emissions/radiation. Further, the additional headroom gained by using MediaTwist® will be retained by the cable after the installation process.

For actual impedance test results of MediaTwist® cable and a traditional Category 5 cable refer to the charts below. The numbers speak for themselves. Belden's MediaTwist® cable successfully ties the process with the real life rigors of an end-user's environment. With MediaTwist®, there truly is no equal!