TH-D72A/E - N3UJJ

2 HOW YOU ENJOY APRS WITH TH-D72A/E (WRITTEN BY BOB BRUNINGA, WB4APR)Contribution by Kenwood to APRSKenwood has developed its series of radios, TH-D7A/E, TM-D700A/E, TM-D710A/E, and now thenew TH-D72A/E to best support the original objectives of APRS. The display of APRS information onthe front panel of these radios gives the mobile operator instantaneous access to all local informationbeing provided on the APRS channel about all surrounding ham radio activities.There are many APRS clients and programs that have been written that sometimes haveconcentrated too much on the display of maps and vehicle positions while leaving out much of theoriginal fundamentals of APRS and the efficiency of the APRS network The Kenwood radios avoidsuch an over-simplistic approach to APRS by implementing a rich and diverse function set. Thefunction set includes almost all of the original functions of APRS that are meant to reinforce theconcept of distributing local information. The Kenwood radios are not just Vehicle Tracking Systems,but are designed to be real-time information distribution systems for mobile operators with thesefeatures:• Position EntryTH-D72A/E with its built in GPS solves the hassle of external connections and setup and alwaysaccurately knows your position. For times indoors the radio has 5 position memories for prestoredfrequently-used positions.• Map Displays on attached GPSAlthough the radio has a built-in GPS, it still has the special waypoint output for putting all otherAPRS positions info on an attached external GPS. When connected to the AvMap G5 series andlater, these position objects will show as any of the nearly 200 special APRS symbols.• APRS Network FundamentalsKenwood fully implemented the more subtle aspects of the APRS fundamentals that assureoptimum network efficiency and channel sharing among all users. New TH-D72A/E supports thedecay algorithm, proportional pathing and SmartBeaconing. These techniques provide goodrefresh rates for new and local information while minimizing the network impact of old and distantdata.• ObjectsThe Kenwood transceivers fully appreciate the value of APRS objects and display themprominently. The object location is shown just like other stations either on the attached mapdisplay or on the front panel with distance and range. TH-D72A/E also includes filters for easysorting of these objects in the list. These objects are what give APRS the local information valueto local users.• Two-Way MessagingUnlike passive one-way tracking devices, the Kenwood radios provide the mobile user with fulltwo-way messaging and display. This real-time human-to-human communications is what makesAPRS so valuable in support of special events and emergencies.TH-D72A/E CONTENTS 13From The N3UJJ.COM Document Library