By Dave Bruse, W4DTR (with a little help from ChatGPT)
What Is APRS?
APRS, or the Automatic Packet Reporting System, is a digital communications system used by amateur radio operators to exchange information in real time. Although APRS is commonly associated with displaying the locations of mobile and portable stations on a map, it can also carry short messages, weather reports, telemetry, event information, repeater frequencies, bulletins, and emergency information.
Traditional APRS activity in North America generally takes place on 144.390 MHz. Packets transmitted by individual stations may be repeated by digital repeaters called digipeaters. Other stations, called IGates, forward packets between the radio network and the Internet.
Get Started for About $5
You do not need to buy a new radio, GPS receiver, antenna, modem, or other equipment to begin using APRS. You can get started with an existing smartphone and an inexpensive app.
Android users can purchase APRSdroid, while iPhone users can purchase the similar APRS TX app. Both cost approximately $5 and can use your phone’s GPS and Internet connection to report your position to the APRS network. Both APRSdroid and APRS TX supports messaging between APRS stations.
This is one of the easiest and least expensive ways for a newly licensed amateur radio operator to explore APRS. Because the apps communicate through the Internet rather than transmitting on 144.390 MHz, no additional radio equipment is required.
Adding Radio Equipment Later
After becoming familiar with APRS, you may decide to add radio capability. The simplest equipment choice is a mobile or handheld radio with APRS and GPS functions built in. These radios can determine your location, create an APRS packet, transmit it over the air, and often display nearby stations and messages.
An APRS station can also be assembled using separate components, including:
- A 2-meter FM transceiver
- A suitable antenna
- A GPS receiver or smartphone
- A Terminal Node Controller, or TNC
- A computer, smartphone, or dedicated APRS tracker
Software such as Graywolf can allow a computer and sound interface to function as a software TNC. This can be an economical way to experiment with radio-based APRS using equipment you already own.
APRS Websites and Smartphone Apps
The easiest way to observe APRS activity is to visit aprs.fi. Enter a call sign or location to see nearby stations, recent positions, movement tracks, weather reports, messages, and other information received through the APRS network.
Windows users should also look into PinPoint APRS (free software that allows you to visually track and communicate with people using amateur radio equipment. During an emergency, it can be used as a location aware tactical communications tool. It is mostly used as a tool for tracking people and assets on a map, although it is capable of so much more).
Android users can use APRSdroid, while iPhone users can use APRS TX. These apps provide an inexpensive introduction to APRS without requiring the immediate purchase of additional equipment.
APRS can be as simple as spending about $5 on a smartphone app or as advanced as building a radio tracker, weather station, digipeater, or IGate. A smartphone app provides an easy starting point, allowing new operators to learn how APRS works before investing in additional radio equipment.