Installing a GPS Receiver

tion here is simple: Either periodically wipe down the face of the transducer with a wet cloth to clear the surface, or prevent the fouling in the first place by using transducer antifouling paint, available at West Marine and other marine supply houses. I don’t recommend that conventional bottom paint be used to protect these surfaces.

If your fish-finder or depth-sounder stops working altogether or begins to send mysterious signals through your display, there are several additional steps you can take to isolate the problem. First, ensure that the display unit is getting power and has a good ground, just as you would for any electrical appliance. Use your multimeter, set up to read volts, to make sure the voltage is not below your unit’s minimum threshold. If it is, determine why by using all of the methods described throughout this book.

Checking your transducer may require hauling the boat so you can get at the face of the unit. If you’re up to it, a brief underwater swim may be all that’s needed. With the sounder turned on, you should hear a ticking noise coming from the transducer as it attempts to transmit its signal. If you don’t hear a ticking sound, the transducer is faulty. Also, if you rub the palm of your hand across the face of the transducer while someone watches the display, they should get a fuzzy reading across the screen. If not, the transducer is at fault and needs to be replaced. Naturally, you should also become familiar with the controls and calibration settings for your fish-finder and depth-sounder and be sure they are set up properly. Installing a GPS Receiver Whether you’re installing a conventional GPS receiver or a chart plotter with an integrated GPS sensor, you essentially need to make the same considerations as you would with all other electronic devices. One thing that will make a minor difference in the installation of your GPS unit is whether or not you select a standard or differential GPS (DGPS) configuration.

Like all of the equipment discussed so far, the location for the display unit must be carefully considMay have a chassis ground

Calibrated Factory Supplied Cable DC + DC -

GPS Antenna May havea chassis ground

Fixed length cable DC + DC -

Fig. 12-13. Wiring layout for a standard GPS installation. GPS Antenna DC DC + Fig. 12-14. Wiring layout for a differential GPS (DGPS) receiver.