Kenwood TM-D710GE - Manual (Page 33)

05 APRS in Action
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While monitoring APRS stations from around the world that may appear on your map, you can easily send messages
to them. An interest is now growing in APRS QSOs where one station may call CQ looking for responses in the
conventional style of a ham contact. Due to the number of characters being restricted, it can be customary to send short
sentences using abbreviated words similar to operating CW.
Searching for weather information can reveal that even adjacent nearby areas can have dramatically differing weather
patterns. Or operating outdoors and timing transmissions to coincide with overhead satellite passes can result in
successful satellite communications using only a handheld transceiver. The opportunities for many activities exist even
without installing a fixed station at home.
Below are two APRS operational examples. In the U.S.A. and Canada, the national APRS frequency is 144.390 MHz.
Let’s Go Mobile
Summary
First, collect and place in your vehicle the essentials necessary for operating mobile. You will need the TM‑D710A/E/GA/
GE transceiver, an antenna and miscellaneous interconnect cables, and a GPS receiver for use with the TM‑D710A/E.
As you travel, you will be looking for position beacons from nearby stations so you can enjoy exchanging messages and
making voice contact.
The TM‑D710 already includes functions for convenient mobile operation. Functions like Frequency Display, Decay
Algorithm, Proportional Pathing and SmartBeaconing are ready to use. Decay Algorithm automatically extends the
transmission interval to reduce traffic loading when the speed information from GPS indicates vehicle movement is
slower than 1 knot. One knot is equal to 1.8 km/h, or just over 1 mile per hour. Essentially, this indicates your vehicle is
parked. Proportional pathing makes sure that local information is refreshed frequently, while at the same time minimizing
network load by transmitting less often at greater distances (number of hops). SmartBeaconing efficiently controls the
rate of beacon transmissions in relation to vehicle speed, direction of travel and network activity. Still other functions
exist to maximize messaging convenience while driving.
Automatic Reply Function
This is a function to return a predefined message such as “Pse QRX. Will return at 12:35” automatically when an APRS
message is received.
Auto Reply is only for passing along special information to anticipated message senders when the operator may
temporarily not be able to respond. It should not be left on for routine operations in most cases because it adds
unnecessary network load. The sending station will always get an ACK, and this is sufficient to know that the message
was delivered in most cases.
Voice Announcement Mode
Voice Announcement mode instructs the TM‑D710 to read aloud any message text beginning with “%” provided the
VGS‑1 is installed. The VGS‑1 can speak a few common ham radio words but can spell any words by letter too.
Entering Characters
Characters can be entered using the DTMF keypad on the microphone as you would when texting from a cell phone.
Additional details of important functions follow.