The most recent handheld RF analyzers and cable testers for telecommunications are multi-functional instruments rich with features, and offer near-laboratory grade performance. This is extremely impressive considering many of these testers, which operate as network analyzers, spectrum analyzers, fault testers, signal generators, power meters, modulation analyzers, amongst other features, can be slung over a shoulder and carried while climbing an antenna tower. Like with all RF test and measurement instruments, however, even these devices are limited by the quality and application requirements of the interconnect needed for them to operate. In the case of handheld testers for telecommunications installation, maintenance, troubleshooting, and field testing, this means coaxial cables, adapters, and test cable assemblies that can survive rough conditions and still maintain metrology grade performance.
Most RF test cable assemblies are designed for sterile laboratory environments with relatively constant temperatures, pressures, and very few contaminates. The greatest threat to these cables is the mishandling of a novice or a coworkers messy take-out. In the case of RF field testing, there is usually nothing sterile or gentle involved in the handling or transporting of test cables. Technicians and operators are often under substantial time pressures, in remote conditions with only their available equipment, and limited in what/how they can carry test equipment. This often translates to RF test cables being wound up, bunched, crushed into carrying cases/tool bags, and banged around along with hand tools, power tools, and other equipment. If this doesn’t sound bad enough for VSWR, phase stability, and PIM performance, the remote tower, underground, industrial, or in-building/on-building telecommunication installations often have a variety of their own hazards and threatening environmental factors. These include wind, sun, wide temperature ranges, corrosives, shock, vibration, and the occasional crushing during transportation, installation, operation.
Typical RF test cables would likely fall out of spec during such treatment, hence there are more ruggedized RF test cable assemblies available. These cable assemblies are specifically designed to offer lab-grade VSWR, phase stability, and PIM performance, while also having protective features to enable a long, and reliable, lifespan. These features include UV-resistant jacketing, material construction allowing for wider operating temperatures, crush and torque resistant armor, corrosion resistant conductor plating, and mechanically sturdy and reliable stainless steel body construction.
As it is often too optimistic to expect a technician to be able to maintain ideal conditions for RF test cables, while meeting quotas and deadlines, using ruggedized RF test cables is a practical solution to the problem. With less reliable cables, technicians may frequently find themselves testing with damaged or derated cables, and either reporting false measurements, or wasting effort troubleshooting phantom anomalies caused by damaged cables. A worst case scenario would be that a damaged cable allows for peak, or sustained, power levels that cause damage to the still-pricey RF test equipment.
Check out our next blog post, “Handheld Analyzers and Cable Testers Require Rugged RF Test Cables Part 2,” where more technical detail about the construction and performance of rugged RF test cables for field applications is discussed.