Broadband Coax

Changes in technology and the introduction of multimedia including broadband Internet, digital television and radio has high-lighted previously unforeseen problems associated with laying cables to reticulate these signals. One major benefit is the stability of these digital signals and the fact the signal degradation is virtually eliminated when copied or reproduced. This permits end users to greatly benefit from improved video and audio quality, interactivity, highspeed data and Internet access, pay-per-view services, simultaneous data/internet access and personalized electronic news.

In a number of cases, the existing "analogue" coaxial cable installed will operate efficiently, however, it is recommended that the newer construction cables be used in all instances to ensure that the signals are not affected. Newer coax cable constructions have been designed specifically for digital transmissions and offer performance advantages over the old analogue designs. These employ a number of design parameters that ensure the requirement of sending higher frequencies over longer distances and through active and passive elements are maintained.

The integrity of the cables electrical performance can be assured if three key elements are maintained:

Correct Installation

Return Loss (RL)

Effective Shielding

Installation Guidelines

Do not step on cables or place equipment on the cables

Avoid excess strain on the cables during installation, remembering the minimum bend radii parameters and avoiding kinks in the cable

Maintain the original physical shape of the cable (excessive pressure from cable ties applied too tightly can denigrade the electrical characteristics)

Return Loss

Solid conductors provide a better impedance stability RL. RL is the measurement of lost signal caused by reflected signal strength to the source. This reduces the amount of signal and increases attenuation of the signal reaching the receiver.

Effective Shielding

Braid shielding is very effective for signals under 10Mhz. Foil shielding is best above that frequency. In digital transmission, both high and low frequencies are used, therefore the use of foil-braid coaxial cable is highly recommended.