2 ENJOYING APRS (by BOB BRUNINGA, WB4APR)
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2.10 Frequency Data Field and AUTO-TUNE (or QSY)
At the nearly same time as we introduced Voice Alert (2004), the Frequency field was added
to the APRS position packet specification. This standardized the inclusion of a voice
operating frequency in the APRS system. APRS was never intended as an end-in-itself,
but as a tool to be applied to all aspects of ham radio and human contact.
Knowing other station’s voice contact frequency in many cases is even more important for
establishing communications than knowing position. Now every ham could announce his
monitoring frequency in his APRS packet and could call others on their indicated frequency.
KENWOOD was the first to leverage the value of this capability by introducing it in all of their
APRS radios since 2007 (the TM-D710A/E, TH-D72A/E TM-D710GA/E and TH-D74A/E).
These radios not only automatically include your voice band frequency in every position
packet but can also then tune to someone else’s, frequency by simply selecting the “
Tune
”
menu as shown below:
In the image above, stations with frequencies embedded in position information packets are
displayed on the screen. This station is the eleventh station in the list, transmits a beacon
of the operation frequency of its own station, and transmits a short message informing other
stations that they are also listening to voice alerts within the simplex communication range.
In this screen, use the
[MENU]
key to recall multiple additional functions.
One is the TUNE function shown on the
screen above.
As in the third image, when TUNE is
selected, the radio automatically tunes to
the frequency of the second band
(non-data band).
Summary of Contents for TH-D74A/E
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