TH-D72A/E - N3UJJ

6 OPERATIONAL EXAMPLES OF APRSWhile monitoring APRS stations from around the world that may appear on your map, you can easilysend messages to them. An interest is now growing in APRS QSOs where one station may call CQlooking for responses in the conventional style of a ham contact. Due to the number of charactersbeing restricted, it can be customary to send short sentences using abbreviated words similar tooperating CW.Searching for weather information can reveal that even adjacent nearby areas can have dramaticallydiffering weather patterns. Or, operating outdoors and timing transmissions to coincide withoverhead satellite passes can result in successful satellite communications using only a handheldtransceiver. The opportunities for many activities exist even without installing a fixed station at home.Below are two APRS operational examples. In USA and Canada, the national APRS frequency is144.390 MHz.6.1 Let’s Go Mobile6.1.1 OverviewIncorporating an internal GPS unit, TH-D72A/E permits APRS operations on its own. Needless tosay, it is also suitable for outdoor mobile operations. When traveling outdoors with the handheldtransceiver in hand, you can search for nearby stations with position beacons to exchange textmessages and establish voice contact.To enjoy APRS operation in unfavorable locations, such as in a building or restaurant, some peopleset up the mobile station as a digipeater.Furthermore, APRS beacons that include latitude, longitude, speed, direction and altitude informationare most suitable for hot-air balloon rides and hang gliding, while the support team usually tracks thewhereabouts of the balloon or glider from the ground.In these cases, since it is necessary to transmit beacons with shorter intervals than usual, operationis on a different frequency from normal APRS operations. Some applications such as Google MapAPRS (http://aprs.fi/) have a function to store the movement trajectory of specified stations and canbe utilized to review the flight of the day or to analyze the trajectory in conjunction with themeteorological data provided by the nearby weather station.Also, the following are some other features that increase convenience of text messaging whilemoving.6.1.1.1 Automatic Reply FunctionThis is a function to return a predefined message such as “Pse QRX. Will return later at 12:35”automatically when an APRS message is received.Auto Reply is only for passing along special information to anticipated message senders when theoperator may temporarily not be able to respond. It should not be left on for routine operation in mostcases because it adds unnecessary network load. The sending station will always get an ACK (anacknowledgment message), and this is sufficient to know that the message was delivered in mostcases.TH-D72A/E CONTENTS 41From The N3UJJ.COM Document Library