Wireless Cables and Connectors

The cable that you select to connect your router to the external antenna for your long distance link will play an important part in how well the connection will perform. I personally use LMR 195 and recommend it above all other cable types currently available. Definetely avoid RG 56 and similar cables as the loss will prove to be unacceptable. LMR 195 will lose approximately 0.6 DB for every metre of cable. Its big brother LMR 400 will loose perhaps half that but is noticably thicker and really only becomes necessary over very long links or when a long cable from the antenna to the router is necessary.

The length of the cable is also another consideration. If you lose 0.6 DB per metre then a 10 metre cable is an instant 6 DB loss. Through practical experience I have discovered that a 10 metre cable should be your objective and 15 metres the absolute limit. Beyond these lengths the signal has real issues getting to the other end of the cable to the antenna where it needs to do its thing. If the cable is going to be longer than this and it is unavoidable consider mounting the router in a waterproof box close to the antenna and using the shortest length cable possible from there and running a cat 5 cable down to the network. Power over ethernet works quite acceptably I might add and can save you some serious headaches trying to get an electrician onto your roof at a reasonable price.

The connectors that you need to put onto the ends of your cable are determined by the antenna or router you are going to be attaching the cable to. Most antennas use either an N-Male or N-Female connector. Routers on the other hand seem to have a dazzling array of different connectors. The most common would have to be a reverse SMA or SMA but the Linksys WRT54GL used in our example uses a reverse TNC connector.

Crimping the connectors yourself is a sensible approach as it allows you to crimp the ends of the cable after it has been run from the antenna to the router. Some connectors are quite chunky and dont go through wall cavities well, requiring larger holes to be drilled in walls etc when compared to the LMR 195 cable by itself. A premade cable gives you less control over the final length of the cable, I would much prefer to have an 11 metre cable Ive cut and crimped myself than have to decide if I can make a 10 metre premade cable fit or use a 15 metre cable instead. Use a quality crimping kit that is designed to crimp the connectors you are going to use. Crimping with a pair of pliers gives an aweful unprofessional looking connection that is prone to failure.