=  NOW 25 WPM  =  TEXT IS FROM JULY 2023  QST  PAGE 58 =

FASHIONED KEYPAD AN OPERATOR ENTERS THEIR CALL SIGN BY USING THE 12
AVAILABLE KEYS ON THEIR RADIO.  ON THE RECEIVING SIDE, A STANDARD RADIO
WITH A DTMF DECODER AND COMPUTER TRANSFORMS THESE SIGNALS TO APRS PACKETS.
IT MAY REPEAT THESE PACKETS BY USING THE AXR25 FORMAT, OR UPLOAD THE PACKET
TO THE INTERNET VIA AN INTERNET GATEWAY.  APRSTT SYSTEMS GENERALLY HAVE A
VOICE CONFIRMATION THAT RELAYS THE TYPED MESSAGE BACK OVER FM.  DURING THIS
PROCESS, A SYNTHESIZED VOICE STATES THE CALL SIGN AND INFORMATION RECEIVED
FROM THE ANALOG DTMF STATION SEE FIGURE 1.  APRSTT ENGINE THE APRSTT ENGINE
MAPS THESE DTMF STRINGS TO CORRESPONDING APRS PACKETS IN THE AXR25 FORMAT.
IT IS THE CENTRAL PROCESSOR OF THE INFORMATION, AND IT TYPICALLY USES
COMPUTER PROGRAMS TO RELAY, ROUTE, AND TRANSMIT INFORMATION.  AN APRSTT
SYSTEM REQUIRES ONLY ONE ENGINE TO CONVERT THE DTMF SIGNALS TO THE APRS
PACKET DATA.  MACRO SHORTCUTS IN THE ORIGINAL DESIGN FOR APRSTT, BOB USED A
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