"Car 54, where are you?"

... a GPS/APRS Tracker for Mobile Emergency Communications Project
Dennis W. Mills, N7MEA
Brian K. Wingate, KC7IWL

1. The KPC3+ by Kantronics is GPS ready and used by many CCARC club members. The W7AIA Packet Station employs this TNC.
Offering the most flexible GPS operations available in a TNC, the KPC-3 Plus allows users to configure and make use of GPS data exactly the way they like. The APRS-compatible KPC-3 Plus can connect to GPS receivers with a NMEA-0183 interface and provides outstanding GPS features. With the multiple string parsing capabilities, users select as many as 4 of the GPS unit's NMEA data strings. Once the data strings are selected, users can specify which of the 4 buffers should be transmitted and can specify the beacon start time as well as the amount of time between beacons for each of the buffers. This allows multiple stations to easily report without data collision. And since the KPC-3 Plus's clock is regularly updated by the satellite-determined GPS clock, the transmission times and intervals are always accurate.

In addition, users can set up a tracking buffer to store GPS data for later retrieval. This buffer is accessible via the KPC-3 Plus's mailbox. The sysop may also reconfigure the GPS unit remotely by connecting to the KPC-3 Plus and simply changing the parameters. KPC-3 Plus (with 128K RAM) --- $129.95 at HRO

Note: The KPC-3 Plus requires a custom-made cable: Hardware Serial Port (HSP) adaptor to permit a single-ported laptop computer to access the TNC and the GPS. The cable has two diodes to permit automatic switching between the tnc and the gps.
Hardware Single Port (HSP) Connectors You can build your own HSP from this schematic or order a complete HSP cable from Kantronics for ($29.95 + sh) You will need a special connector to wire the HSP to your GPS. If you use a Garmin II+, I recommend Blue Hills for plug. If you are going to use your laptog, then you will want to have the data/power cable that has the Garmin plug which is unique and not easily available.
Note: The new firmware 8.3 for the KPC3+ includes a built-in 2nd serial port.

2. The Garmin II+ is a very powerful twelve channel parallel receiver for quick satellite acquisition and enhanced reception. This compact GPS features two-way screen display for vertical or horizontal orientation. It features an adaptable navigation page with either compass or highway steering guidance, and user-selectable fields. User-selectable waypoint symbols enhance map display information. The TactBack feature lets you quickly navigate your track log back home without manually storing waypoints. The Garmin II+ GPS works very well with TNC's like the KPC3+ or the PicoPacket. This model has an external antenna connection that is useful for keeping the Tracker in a trunk. GPS satellites need to see the antenna to work! This unit sells for $269 at West Marine in Delta Park-Portland, Oregon or HRO
http://www.garmin.com/db?MItab=garmin&MIval=splash

3. A GPS Antenna (external antenna models recommended)
Magmount for GPSII+ ($60 + shipping from TAPR)

4. ICOM 2100H or Radio Shack HTX-242 45 Watt mobile

We recommend a 50 watt mobile to serve the dual purpose of a field-based radio that can use full power if needed for voice communications. HRO

4. MFJ TNC/MIC Switch KAM/KPC3VHF The switch will permit you to switch the mobile radio between packet (APRS data transmitted) and voice. ($39.95 HRO)

5. Software

Precision Mapping Streets 3.0 When combined with WinAPRS software, PM 3.0 will give you extremely accurate maps wherever you are. CD-ROM for $50.

Automatic Position Reporting System Download software for Windows (WinAPRS) and Macintosh (MacAPRS). The latest version now incorporates Precision Mapping Streets 3.0 for really great street level mapping. You can run the software without registering it, but cannot save the the settings. ($60)

6. Battery Box I recommend the Action Products Power Caddy Battery Box that can be mail-ordered through Cabela's ($50.44 delivered). It will hold an 85 amp hour deep-cycle or marine battery and all the ham equipment! It comes with a plastic carrying handle, galvanized catches, strickes, hinge pins and terminal connections, battery charge indicator gauge, 2 fused accessory jack plug ins, 30 amp DC fuse, and external brass connector lugs. Measures: 16"L x 8.25W x 12.5H (CJ-01-0772 $44.95 http:www.cabelas.com)

7. Deep Cycle Marine Battery-33 Amh B ($75.00) West Marine

8. Magmount 2 Meter Antenna ($14.95 MFJ) HRO

9. Power/Data Cable for GPS ($25.00) Blue Hills

10. Cable and Connectors (est. $15)

11. Laptop Computer (requires CD ROM drive for Precision Mapping Streets 3.0)

The CTX-770 MX-SJ combines a brilliant 12.1" screen fed by a 128 bit PCI graphic VGA accelerator for blazing graphics performance. This combined with high end audio and a sixteen speed CD-ROM harness the power of the 200MHz Intel Pentium® Processor with MMX^TM Technology to create an on-the-road, off-the-road, warrior you can depend on. Wrapped up in a package that weighs under six and a half pounds. ($999.99)

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