Car GPS Navigation Systems - A Buyers Guide

By Nicola Carr

SUMMARY: GPS navigation systems are advancing every year to include added features such as traffic and weather reporting and integrated multimedia players such as mp3, dvd movies, games etc. This buying guide outlines the core features of gps navigation systems and how to compare them.

In 1973 the U.S. Department of Defence launched the Navstar GPS network. This consisted of 24 satellites orbiting the earth every 12 hours and five ground stations. This positioning system was made available for public use. With this capability, consumer location devices were produced to accurately determine location and other data such as current and average speed, directional heading, and elevation. These GPS devices need an unobstructed view of at least four satellites to provide a reliable 3D fix.

The GPS receiver overlays this location data onto map files stored on the unit, to give a current position on the map as well previous track. The receiver constantly recalculates position, giving real time position.

A typical GPS device contains:

• 12-channel receiver - the quality of the receiver determines how long it takes the device to acquire a 3D fix.
• Antenna to capture satellite signals - positioned to get a clear view of the sky.
• CPU to process the data and overlay on maps
• DVD Hard-drive - where maps on DVD's or available online are uploaded and stored. Some cheaper units do not upload the maps, but reference them off the DVD or CD.
• Display Screen - mostly color with handheld units using black and white
• Voice Interface - more advanced units

How The GPS Device Gets A Fix

The first time you start your GPS device, its data store is blank so needs a to collect satellite information to determine your position. This is known as a cold start. Some units only take 30 to 45 seconds to acquire a 3D fix during a cold start, while others can take several minutes. Subsequent position updates only take 3 to 4 seconds. If you go out of range from losing line of sight, such as passing behind a large building or through a tunnel, a good receiver will instantly recover, whereas weaker units will require more time to reacquire a 3D fix.

How Different GPS Navigation Units Differ

Location of Antenna - A factory installed in-dash unit antenna is integrated into the dashboard where it has an unobstructed view of the sky. Many portable models have a suction-cup-mounting device to position the device on the windshield. Add-on antennas are also available. Regardless of the type of unit and antenna, the important thing is to keep the antenna visible to the greatest area of sky possible. Choose a unit where this can be done AT THE SAME TIME as being able to maintain a clear view of the screen.

Screens and Display - important to check how bright these are, and if they are clearly visible from the mounted position in bright day light. Onboard navigation systems are generally color screens, and portable units are black and white to save power. Larger screens and integrate better with other vehicle electronics.

Input Buttons - most enroute buttons are on the display screen. Ensure these are easy to use when driving; that is they are big enough and colored sufficently to see without causing a driving hazard.

Map Media - Earlier models were CD-based, requiring multiple discs to cover the entire United States. Newer in-dash systems are DVD-based; only 1-2 DVD's required for an entire country of maps.

Cost - In-dash systems are usually more expensive than portable counterparts. Aftermarket in-dash models usually require professional installation and can be just as expensive as the factory models.

Upgrading - always check how easy it is to upgrade the firmware and maps on your GPS unit. Some units detach a portion to be connected to the computer via USB, whereas others are done using a DVD. Those units which can be upgraded online, are much more convenient.

Added Features of GPS Units

Apart from giving you a current position, a number of GPS navigation devices can give you:

• A track of where you have been - the number of tracks and waypoints stored varies from unit to unit. You may also want to save on part of a track for future use.
• A path from your current position to your destination
• Maintain commonly used navigation paths for reuse.
• Points of Interest - user sets the types of points of interest, such as tourist, bank ATM, petrol stations, historical, accommodation, restaurants etc.
• Real time traffic reporting to avoid traffic delays. This can also include road works.
• Voice recognition to receive destination instructions, and voice guidance to give driving instructions
• Weather updates
• Street name navigation - instead of just turn left 200m it was say 'Turn left into Stanley St'
• Integrated Multimedia players - MP3 players, image viewers, and audio books.
• Onboard or Portable GPS Navigation

The downside of onboard GPS Navigation units are susceptible to theft; and you cannot take them with you to use in other vehicles or when travelling abroad. Portable units, such as the Garmin StreetPilot 2720, can be used in multiple cars; being easily moved from car to car. Depending upon the power supply and portability, portable and handheld units can be taken when travelling or used on cycles, boats, private aircraft etc.

The Secret To Door Panels And Door Speakers

By Matt Brooks

SUMMARY: For some, the prospect of changing out speakers is a daunting one, since you have to remove the door panels to access the speakers tucked away within its walls. They are not a tricky as they seem, if you know the right techniques.

For some, the prospect of changing out speakers is a daunting one, since you have to remove the door panels to access the speakers tucked away within its walls. They are not a tricky as they seem, if you know the right techniques.

The first thing to do is to locate any screws holding the panel in place. These are generally found in or under the armrest piece, in the door opener latch, or near the bottom of the door panel. Remove as many as you can find to start.

With the screws removed, you will need to carefully pry the door panel off the door. Start in the bottom corner nearest the speaker. Gently pull the panel until it pops loose. There are usually several clips holding it in place. Work around the bottom of the door panel popping the clips out. Be careful to not break them, because you will need them to reinstall it. Continue around the outside of the panel until you have removed as many of the clips as you can. If you have power windows, doors, etc, remove the control panel from the door panel. It is usually clipped in place, and can be carefully pried out. Look for small notches that may give away the position of the clips. If you have mechanical windows, you will need to push the door panel into the door at the window crank, and look for the snap ring clip holding it in place. With a thin flathead screwdriver, pop the clip loose, taking special note of where it goes, as you will need it to secure the piece back in place. Once this is removed, you should have enough clearance to reach the speaker. If not, you can attempt to completely remove the door panel by sliding it upwards and out of the window compartment. You may be caught up by the door opener latch. These can be a little tricky, as some will slide in place horizontally, screw in, or pop out. Look for screws, and if you don't find any, try sliding it horizontally towards the inside. If that doesn't work, see if it pops straight out. It will be connected to the bars that pull the door latch, so they will have to be positioned correctly for the door panel to be removed. If there is a triangular piece of trim in the top corner of the door panel, you will need to remove it also. It also clips in place and can be removed. This should allow the door panel to slide out, assuming you have disconnected the control panels electrical wires.

You should now be in full view of the door speaker. it can be removed by removing the four screws holding it in place. You may also find that the connectors on these speakers won't work for your aftermarket ones, so you will have to clip the wires and attach the end connectors provided with your speakers. Pay attention to positive and negative here. If you are unsure of what is what, there are a few ways to check. Look at the terminals on the factory speaker. It may have a "+" and "-" sign designating positive and negative. If it doesn't tell you, you can log on to installdr.com and look up the color codes for the speaker, or try the battery test. Take a good charged battery and place one of the factory speaker wires (attached to the speaker) on the positive, and one on the negative of the battery. If the speaker pushes out, the polarity is correct as you have it, and attach the wires accordingly. If it pushes in, the polarity is reversed, so reverse the battery and try again. If it pushes out, wire the speakers following that polarity.

Install the speaker in the door by replacing the 4 screws and securing it in place, and reinstalling the door panel. be sure to slide it back down in place, and line up the clips exactly before applying pressure to reattach them. You don't want to break any of those. Finish screwing the door in place, then attach the window control panel/window crank, and congratulations, your done!

Car Care and Protection

By Janet Smith

SUMMARY: Easy tips to keep your car looking and performing great.

When you get a new car, you’re protective and careful to keep it looking and performing great. As time passes most of us get a little less interested. Taking the time to protect and keep your car looking great not only helps the look, it can also help to maintain the value of your vehicle.
For instance, roll up car care covers, which can be custom fit to protect your car anywhere while sitting outdoors. These covers can protect your vehicle from outdoor elements, dirt, pollen, and other items that hamper the looks of your car. Another great alternative to parking your vehicle in a garage is to use a parking shelter or canopy.

Importance of Car Care and Maintenance

Car care and maintenance isn’t always convenient but they are necessary components if you want to keep your nice vehicle running. Here are some ideas to make car care less of a hassle: As far as maintenance, keeping up with regular scheduled oil changes, tire rotations, inspections or other special maintenance your vehicle may need can keep you from having many issues later on.

Any time you hear a weird noise, feel vibrating that is unusual or see a warning light that shouldn’t be on, the quicker you can get your vehicle to a garage the better chances you have to keep something serious from happening. Continuing to drive longer than necessary in these situations can create big and expensive problems.

Cleaning and Car Care Accessories

Clean your car in a snap without paying the price of a detailing shop. It’s easy with the right car care accessories to lighten the load. Foam and spray nozzles like we all used to use at the quick car washes are now available to attach right to your own water hose, making it simple to have soap and rinse options all in one nozzle. Also new at many of your specialty retail stores are the automotive detailing kits that have everything in them to make your car sparkle.

For inside car care, the wet/dry cordless vacuum is a must have item. Not only will you be able to clean up dry messes but also liquid spills as well. If your vehicle includes vinyl or leather, don’t forget to use specific car care cleaners on these delicate items especially if they are often in the sun.