Packet Network Growth - Kenwood TH-D74A/E Operating Tips

2 ENJOYING APRS (by BOB BRUNINGA, WB4APR)
communications support for the Old Dominion 100 mile endurance run. For this event in
the mid1980s, the first vestige of APRS used Vic-20s and packet radio to share information
on the hundreds of runners and horses across the hundreds or so square miles over the
24-hour event.
There was no such thing as GPS. The system consisted of simply a packet channel where
each checkpoint beaconed information and objects about arrivals and then transferred
object responsibility as it was taken over by the next checkpoint. At any instant, everyone
could see on their screens, a list of the objects reported at each station and their status.
New information was beaconed at a high rate for immediate delivery but decayed rapidly to
reduce channel loading so that fresh information had priority with minimum collisions.
This was the core concept that became APRS.

2.3 Packet Network Growth

Beginning in 1983, we added VHF, HF and a phone line to the club packet BBS to provide a
store and forward capability and began expanding to the Commodore 64. It was linked
with other systems on 145.01 MHz 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 congested/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. Everything was evolving to store-forward messaging (like internet email
became over the next decade) and real-time digital human connectivity was lost.
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
callsign so nicely.
9