Table of Contents -

• PACKET
• AUTOMATIC POSITION REPORTING SYSTEM (APRS)
• PHASE SHIFT KEYING 31 (PSK31)

HIGHLANDS COUNTY PACKET

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AUTOMATIC POSITION REPORTING SYSTEM (APRS)

APRS is a system which uses the BEACON command of packet radio to transmit information and your current Latitude and Longitude coordinates, obtained from a Global Positioning Satellite (GPS) receiver, to all others listening on the frequency (2 Meters is 144.390). By having software in the computer to display an area map, you have what may be considered an air traffic control system at ground level showing everyone's location on the map and moving over time as people move.

There are five types of APRS Stations:

• Simple Tracker - Periodic moving broadcasts
• Tracker with a PC - Simple Tracker plus viewable maps
• Fixed Station - Periodic broadcast plus viewable maps
• Weather Station - Fixed Station broadcasting weather
• Internet Gateway - Fixed Station interfaced with the Internet

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PHASE SHIFT KEYING 31 (PSK31)

PSK31 is a system which phase shifts a radio signal at an audio rate of 31 hz to generate zeros (0) and ones (1) in ASCII format to receive and transmit text. For a complete description of how it works, go to the web site and read the PSK31 fundamentals.

The software (DigiPan) needed for this mode is available free at the official PSK31 web site.

The hardware needed for this mode is your computer sound card and some easily built interface cards. The directions of what to build and how to hook all this up is available at the WM2U PSK31 web site.

An article on PSK31 can be found in the May, 2000 issue of QST (page 42) which includes listing the various problems an amateur may encounter and the solution to the problem.

Frequencies to look for PSK31 activity: 1838.150 3580.150 7035.150 (Regions1,3) 7070.150 (Region 2) 14070.150 18100.150 21070.150 24920.150 28120.150 50290

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