3. Doing the Battery Twist: If you use a portable electronic device, say a handheld GPS receiver, it undoubtedly uses batteries. Even panel? or deck-mounted electronic devices likely have internal batteries that maintain memory and let you use the device if the boat's power fails. Even though you've been installing batteries since you were a kid, not paying attention can spell trouble. A common error is to install them upside down. Most devices have a label or an imprint that shows you which way the batteries go in. Look carefully, those images are often tiny and faint. Reverse the directions of all the batteries and you reverse the polarity. How can this cause damage? The more batteries you incorrectly install, the greater the voltage you empower the device with. It's the same as reversing polarity on an installed device: Your unit may not turn on, may blow its power protection, or may end up as smoking scrap. One tech support rep told us that reversing the batteries can cause batteries to leak or explode. Leakage can cause corrosion, preventing new batteries from making a connection.
By the way, there's a reason manufacturers recommend alkaline batteries. They do a better job of letting a device shut down under low-battery conditions. Cheaper batteries may lack the voltage to let a device save information before turning off.
4. What Leaks Out: Most manufacturers tell you to remove the batteries from a portable device when storing it for a long period of time. Why? Batteries corrode. Remember that flashlight you once had - where the batteries began to look like moldy bread? The same thing can happen to your boat's electronics, which cost a lot more than a five-and-dime flashlight. In most cases, the gunk that leaks from the batteries gets all over the contacts in the battery compartment, causing them to corrode and no longer make adequate contact with the battery. Batteries can also leak into the compartment where the circuitry is located. If you're wondering how this could occur with a waterproof device, remember that the batteries might be inside a watertight compartment right next to the stuff that makes the device tick. Also, if you install backup batteries, replace them according to the manual's schedule. Forget, and all your waypoints could be lost during storage.
5. Any Way You Splice It: Another installation hazard occurs whenever you cut and splice cables or wires. Manufacturers try to be generous and give you more cable than you need to run to an external antenna or transducer. However, when you have 50 feet of cable that has to run only 10 feet, your first inclination is probably to cut and splice it. Wrong. GPS cables, for instance, require the impedance provided by the long cable. Cut it and your unit's sensitivity will be diminished. Coil long cables whenever possible. There are also those of you who don't want to cut a big hole in the deck to run a bulky connector through, when a hole the size of the cable will do. You can clip the connector, run the wire, and then reinstall the connector. But, many cables, particularly coaxial ones for antennas and transducers, require advanced splicing techniques.
Any time you cut a cable, you expose its inner workings to the elements - particularly moisture - which can lead to internal corrosion. Even worse, you can short the wires in the cable when you put it back together, which can cause the antenna or transducer to malfunction. Even if you make a successful splice, you may change the impedance characteristics. In other words, the length of the cable is designed to help a device work optimally and changing its length may affect the performance.
GPS manufacturers who provide their customers with antennas that are powered ("active") run into cable length issues all the time. Because of aesthetics or space considerations, customers often cut their wires and don't put them back together correctly. The result is shorts. In some cases, the lucky customer can simply purchase another cable from the manufacturer. In other cases, depending on the unit, the short or miswiring can damage either the antenna or the receiver, or both.
6. Too Close for Comfort: It's not uncommon for the antenna of one device to interfere with the antenna of another, particularly when they're in close proximity. For example, a radar's antenna can interfere with the operation of a radio and that of a GPS receiver. Generally, if two products operate at or near the same frequency, interference is likely. To minimize that risk, be sure to give each antenna as much room as you can. Also, route the cable from each device through different paths. For example, if the cables from devices come down into your nav station, try running them in from opposite sides. Although interference won't cause permanent harm to electronics, one device can make another inoperable. What did tech support report? GPS receivers and older loran receivers are often susceptible to radar interference. To avoid this, check the radar's manual for its beam-width angle and mount the other antenna above the radome and out of the imaginary lines this angle describes.