RF coaxial cables are widely used for a range of professional RF applications. While RF cables are extremely easy to install, it is just as essential to ensure proper cable installation to make it last for longer periods of time. This is mainly important because many cable installations are done externally and they need to withstand the effects of severe environmental conditions.
Since RF cables are available in a large variety, one need to decide on the required impedance before installation. Usually domestic hi-fi equipment and video antenna feeds use 75 ohm coaxial cables as compared to professional applications that use 50 ohm. After choosing the required impedance, decision also needs to be made on the level of signal loss that is suitable to the user. As a rule, the lower the signal loss is, the greater the diameter as well as the cost of the cable.
Once an acceptable cable has been purchased, the following steps must be considered while installing the outdoor RF cable:
1. While installing the cable, make sure that it is properly weatherproofed to prevent any moisture from entering the cable. Moisture is bad as it leads to a significant signal loss apart from causing the outer shield of the cable to oxidize. Therefore, seal the end of the cable that is to be used externally to ensure that it doesn’t let any moisture in. Also, the outer cable shield must remain intact and not be damaged during installation. One can also loop the cable up and down as doing so will only make water move along it and keep it from entering the cable.
2. Since all coaxial cables have bend radius, they should not be bent further than this. Doing so will damage the inner construction of the cable thereby leading to higher loss of signal levels. One must also take care with regard to the cable being crushed or likely to get crushed. Because in this case, the changed dimensions of the cable will be unable to maintain its impedance.
3. One can consider running the cable under a manufactured conduit as well to ensure easy replacement later on. However, care must be taken that the conduit doesn’t become water-logged.
4. When installing an RF cable, it is important to accurately terminate the cable. In most cases, the cable will get electrically terminated by an RF connector, the termination being either at an antenna or into a receiver. Accordingly, the right quality RF connectors should be used to make the connections correctly. Connectors available for domestic installations are often poor in terms of their electrical RF performance. As compared to them, professional RF connectors are far better but it is necessary that the connectors suit the frequencies being used. Hence, while purchasing the same, ascertain that well-branded connectors are bring bought and from authorized stored only.
Exposure to climatic elements will wear the cables down and only a timely replacement will help resolve the issue of lower performance. But only with a proper and correct installation of an RF cable can one be guaranteed of an extended period of satisfactory service.