2005 Lincoln Town Car Owner Guide 2nd Printing - Page 98

Entertainment Systems Radio reception factors There are certain factors that may effect your radio reception. • Distance/strength. The further an FM signal travels, the weaker it is. The listenable range of the average FM station is approximately 40 km (24 miles). This range can be affected by "signal modulation." Signal modulation is a process radio stations use to increase their strength/volume relative to other stations. • Terrain. Hills, mountains and tall buildings between your vehicle's antenna and the radio station signal can cause FM reception problems. Static can be caused on AM stations by power lines, electric fences, traffic lights and thunderstorms. Moving away from an interfering structure (out of its "shadow") returns your reception to normal. • Station overload. Weak signals are sometimes captured by stronger signals when you pass a broadcast tower. A stronger signal may temporarily overtake a weaker signal and play while the weak station frequency is displayed. Principles of GPS (global positioning system) operation Your system directs you based on information derived from global positioning satellites, road maps stored on the DVD, sensors in your vehicle and the desired destination. The system compiles all necessary information to guide you to your selected destination. Space satellites determine the vehicle's current location and transmit position and time signals to your car. If the vehicle has been parked for a long period of time, the navigation function may be temporarily unresponsive. The navigation system will operate reliably again once GPS reception is available for a few minutes. Limited GPS reception System performance may be adversely affected if GPS reception is interrupted or interference occurs over a distance of several miles. The following are possible causes for GPS reception being interrupted. If the vehicle is: • in multi-story parking garages • in tunnels and under bridges • inside or in between buildings • by forests or tree-lined avenues • in heavy rain showers and thunderstorms • in valleys and in mountainous regions 98 2005 Town Car (tow) Owners Guide (post-2002-fmt) USA_English (fus)