User Guide

2 HOW YOU ENJOY APRS WITH TH-D72A/E (WRITTEN BY BOB BRUNINGA, WB4APR)
TH-D72A/E CONTENTS 5
Packet Network Growth
Beginning in 1983, we added VHF, HF and a phone line to the Vic-20 as well as a BBS message
store and forward capability and began expanding to the Commodore 64. It was linked with other
systems on 145.01 and had the first dual-port HF link onto the 10.149 MHz HF packet frequency we
still use today for APRS. It was an exciting time, but packet radio was being used more and more for
connected point-to-point traffic and then to BBS systems and the real-time connectivity between
operators was being lost. By that time, live beacons to announce real-time activity and to conduct
group chats by UI messaging was not only disappearing but were actually being outlawed on the
shared BBS channels. Even UI digipeating was being disabled in all packet nodes to make sure that
no one beaconed or chatted on the BBS network and dozens of restricted/exclusive use packet
frequencies.
But we still wanted that live operator-to-operator UI packet chat capability and we still needed a
tactical real-time local communications and information distribution channel for rapidly exchanging
digital data of immediate value to local operators and operations. In 1992, we abandoned the
Commodore 64 and switched to the new IBM AT personal computer running at 4 MHz and changed
the name from the Connectionless Emergency Traffic System (CETS) to Automatic Packet Reporting
System (APRS) since it matched my call so nicely.
APRS in 1990s
I formally presented APRS at the TAPR/ARRL Digital Conference in 1992. APRS really took off as
the cost of GPS got below $500 each and I manually digitized the entire U.S.A. and some other
countries using coordinates measured from paper maps. It was during these times that the “P” was
temporarily called “Position” to highlight this new capability. Unfortunately, this was a mistake. Over
the next decade as GPS became readily available, too many hams only saw the position maps of
APRS and not the broad communication applications for human-to-human tactical ham radio
information exchange in real time. Too many operators bought transmit-only GPS trackers and
further ignored the real-time human communications element. Many follow-on software clients
focused on maps with little attention to the underlying network protocol and human-to-human
connectivity.