| I've owned a Magellan Trailblazer XL for almost 10 years. A few years ago, I bought a Kenwood TM-D700A and interfaced the XL to the rig for APRS. The XL would not receive signals inside the house and didn't have the ability to upload waypoints or display maps on its screen. Accuracy was another issue with the Magellan. I decided it was about time to replace the XL with a more modern unit and started reviewing different units. Man, GPS technology has come a long way since my black and white Trailblazer. I looked at units from Magellan, Trimble, Garmin and others, but ultimately decided upon the Garmin 276C, due to its features set. The 276C is one of the few GPS receiver I'm aware of, that can operate in Automobile or Marine mode. In Automobile mode, it will display a base map with major roads and cities displayed. In Marine mode, it configures itself to display various marine items. You can also purchase more detailed maps for the unit, such as City Select or Blue Chart. The purchase of optional maps also requires the purchase of an optional memory card for the 276C, since it doesn't have internal memory for storage of the maps. The 276C will support up to a 256 Mb Garmin Memory Card, which is a proprietary card. While some GPS receivers will accept widely available CF, SD or other-type memory cards, the 276C does not. While this is something I wish Garmin had addressed differently in their design, it's only a minor speed bump and does not effect the overall rating, as the cards are reasonably priced. Once installed in the 276C and the optional mapping software is installed on your PC, a highspeed USB 2.0 port is used transfer selected areas or regions to the memory card. To give you an idea how much data a card can hold, with the 128 Mb card installed in my unit, I am able to load all of Virginia and part of a second state. This last summer, I took the family on vacation to the Midwest (Iowa) and Northern Wisconsin. Although I did not have the Garmin at the time, I was able to load the detailed maps for the entire trip into the unit (from VA. to Ia.). With 256 Mb, it should be possible to load all data for a cross country trip. The optional maps are fairly accurate (City Select v7.0), but I have found a few minor discrepancies. One more small gripe I have about the 276C, is auto route feature, but that may be due to a configuration setting that isn't right. It will occasionally take the long way home, when using it to navigate from point A to point B - again, I may not have the preferences set up correctly. With an external speaker, the Garmin will also talk to you, which is handy when you're in traffic and can't look at the screen. The 276C also seems to have a strong receiver, since I'm able to lock onto several satellites most anywhere in our two-story home - even on the first floor. The screen is bright and easy to read, even in a bright vehicle. Accuracy is not an issue with the 276C. Using WAAS and satellite 35 on the East Coast, I frequently see 2 meter accuracy. The Lithium battery allows you to carry the unit with you and can power it for up to 15 hours. The GPS antenna is detachable, which provides easy access to the BNC connector. I have an active antenna on the SUV and the Garmin provides the power to run it. The Garmin has two connectors - one is for USB and the other is the multi connector, which takes care of power, alarm, speaker output and two serial ports. The 276C comes with a bare cable, so you can easily interface it to your TNC. I soldered mine to a standard DB-9, which plugs into an interface box I built. This box has a second DB-9, which can be used to plug into a laptop or radio, like the Kenwood TM-D700A. I also added a standard 1/8" audio jack, which lets me plug in a small Radio Shack communications speaker, which sits on the dash. The radio and GPS work flawlessly together. With the GPS set to NMEA IN/NMEA OUT and 4800 baud, and the radio set to similar settings, I am able to transmit position packets and also display received packets (position and callsign) on the screen of the Garmin. My Magellan would display callsigns in a list, but would truncate them, which was unusable. I would recommend purchasing the Automotive Navigation Kit, which comes with an unlocked City Select v7.0 DVD, a couple of automotive mounting options, a 128 Mb memory card and a 12 vdc plug/speaker combo. I highly recommend the 276C. If you buy one, you won't be disappointed. If you shop around online, it's possible to locate it for under $600. |