June 16, 2026 – “Packet Radio”

Good evening. This is W1UT and tonight’s training is about “Packet Radio.”

This is an interesting topic that was popular back in the 1980s and 1990s and is still used today but is not as popular these days mainly due to the universal use of the internet and cell phones. Packet radio is the application of packet switching to digital radio communications, utilizing the AX.25 protocol adapted for amateur radio.

Amateur radio operators began experimenting with the technology in 1978 in Montreal, Canada, using home built equipment to transmit ASCII data over VHF frequencies.  The first US amateur packet radio activity occurred in December 1980 in San Francisco, following FCC authorization for ASCII transmission.  The establishment of AMPRNet provided IP address allocations for amateur use, and by 1983, the Tucson Amateur Packet Radio Corporation (known as TAPR) released the first commercially available Terminal Node Controller (TNC) in kit form. 

Packet radio proved its value during emergency operations such as the 1986 Aeromexico crash. While interest waned with the rise of the public internet, the protocol remains in use for applications such as APRS (Automatic Packet Reporting System) and is experiencing a modern renaissance through open-source software and renewed interest in independent, non-internet-dependent data networks.

Using AX.25, it is possible for any packet radio station to act as a digipeater which allows linking distant stations with each other in a pseudo network. This makes packet radio especially useful for emergency communications.

Packet radio can be used in mobile communications. Some mobile packet radio stations transmit their location periodically using the Automatic Packet Reporting System (or APRS). Some VHF/UHF radios come equipped to transmit location via APRS. If the APRS packet is received by another station connected to an i-gate station, position reports and other messages can be routed to an Internet server and made accessible on a public web page. This allows amateur radio operators to track the locations along with telemetry and other messages of vehicles, hikers, high-altitude balloons, etc., around the world.

For those interested in trying out packet radio all you really need is a software app and other packet stations in your vicinity. I personally played around with packet in the 1980s using what was then called a Terminal Node Control (or TNC). Technology has certainly moved forward since those days. If you are interested in this mode, google Packet Radio and you can learn much more about this mode.