This question came in from a reader last week: “I want to install a cell-phone booster antenna system on my boat. Is there anything I need to be concerned about as part of this installation?”

Cell-phone attenna kit

With this Digital Antenna booster kit, onboard cell phone(s) transmit to the mini antenna mounted on the amplifier box shown. The amplified signal is then sent via the coaxial cable shown to the larger transmitting antenna.

Cell phones have certainly become the primary means of communication for most boaters. Range to the cell towers is of course an issue at some points along coastal waters. So, wanting to extend your range is a reasonable thing to do. The systems I’m familiar with promise to extend cell phone coverage  from 30 to as much as 50 miles offshore. Also, there are several system types available for on board use. Some systems use a wired connection to your cell phone with an antenna mounted as high on your boat as possible. Other systems use a wireless base station/ amplifier that transmits a repeated signal to the antenna system installed on board.

Some key things come to mind relative to what could impact the performance of these systems. First, the quality of any coaxial cabling used to connect the antenna to the amplifier or repeater is critical. No matter what type of radio equipment you are working with, get the best coaxial cable you can find to connect antennas to the various devices. Also, keep cable runs as short as possible. Actual signal strength is in part dictated by these cables, the longer the run, higher the component operating frequency and smaller the cable, the more loss you will end up with. The best advice here is to be sure to follow your equipment vendor’s recommendations.

A second issue you can run into is interference from other on board equipment. For example, modern cell phones operate in a frequency range that is fairly close to the GPS frequency range. This means you would want to be certain that your cell booster antenna and GPS receiver antenna are well separated. NMEA, for example, recommends a minimum of 5-foot horizontal separation between a GPS antenna and a cell-phone antenna. Also, they recommend keeping the cell-phone antenna out of a radar beam. So, antenna placement is a key concern as part of these installs. Since cell phone signals are considered “line of sight”, getting the booster antenna as high as possible is also important, but be sure to consider some of these other potential problems.