Belden’s Steve Lampen presents:Maximizing HD Cable Performance

Steve Lampen, Multimedia Technology Manager for Belden in the USA, presents a keynote presentation entitled Maximizing HD Cable Performance, at a seminar organized by Belden at CABSAT 2008 in Dubai. The author of The Audio-Video Cable Installer's Pocket Guide (published by McGraw-Hill) and columnist for Radio World Magazine, Mr. Lampen is internationally renowned for his interesting and stimulating seminars about cable technology.

As Belden is showcasing its cable developments for HD offering extended broadcast quality at CABSAT, in his presentation Steve Lampen explains how to maximise and maintain the very best high definition performance for HD cable. He discusses understanding and overcoming problems, knowing what to look for, how to compare different cables and the best practice to adopt for installation.

Steve Lampen opens with an introduction to coaxial cables, a construction where all the components lie on the same axis and highlights the advantages that the coaxial cables offer. He uses illustrations to explain how impedance is determined by the size of the center conductor (AWG), and the relationship of attenuation, power and voltage, and he illustrates low and high impedance and how this relates to frequency (MHz).

Factors which affect cable performance

Steve Lampen also talks about the factors which affect cable performance and points out that a cable can be damaged in several ways such as being crushed or stepped on, bent, tied in knots, subject to torsional twisting and a host of other reasons. Damage like this will decrease dB which means inferior performance. Another factor is known as periodicity, caused and tested by crimping the cable every 1.5m (5ft) and/or badly hand-tying together.

Another influence on cable quality and performance is the density of the foam and the amount of air in a closed or open cell formulation. Cables can easily suffer from deformation, such as being stepped on, crushed by equipment or being pulled through a conduit. Similarly, the bend radius is important, especially if the cable is low-density foam because bending puts stresses on the centre. The solution is to use cable with high crush resistance and a high-density hard-cell foam.

Steve Lampen shows how Belden’s 1505A and 1694A cable perform when compared with equivalent cables from other manufacturers, many of which fail to withstand resist much lighter loads.

Steve Lampen concludes his presentation with discussion and illustrations of the different methods and equipment for testing. He explains why, unlike many manufacturers, Belden test their HD and other cables to 4.5GHz and why that is so important and useful for installers. The bottom line is that a fundamental understanding of which and why some cables are better than others, and how they are treated and installed on site, is vital in maximising HD cable performance!