What Is Akiss Modem - Kenwood TH-D74A/E Operating Tips

3 APRS
3.1.5 Restricting QSY Information (New Feature)
This is a new QSY feature for the receiving end. It is used to restrict the "Tune" operation
to only data within a specified distance range from one's own station.
For example, if the receiving station in the FM mode or DV mode is located at a remote
location that is unable to receive radio signals directly, the "Tune" operation would be
meaningless.
In this case, a distance range can be configured to restrict tuning of these receiving stations.
（→ Menu No. 523）
3.1.6 Beacon Transmission from a Fixed Position During GPS Track Logging
For models up to until the TH-D72A/E, GPS information is always used when GPS is turned
on for APRS beacon transmission. This can be inconvenient in cases where a station
wants to enable track logging but does not want to reveal its position to other stations.
On the TH-D74A/E, the positional information selected in the menu is used for the beacon.
The options available are: "GPS" and "My Position 1" to "My Position 5". A station is able
to turn on GPS to obtain the track log while configuring its own position to "My Position 1",
for example.
（→ Menu No. 401）
3.1.7 Registering the Beacon of My Station that is Digipeated in the Station List
For models up to the TH-D72A/E, the beacon of my station that is digipeated is not
registered in the APRS station list.
However, it is now registered on the TH-D74A/E. This allows a station to check the APRS
information that is being transmitted from an objective viewpoint.
3.2 What is a KISS modem?
3.2.1 What is KISS?
KISS is the abbreviation for "Keep It Simple, Stupid". This was proposed by K3MC and
KA9Q at the "ARRL 6th Computer Networking Conference" in 1987. It is a simple modem
with protocol control (AX.25 protocol) removed from the TNC (Terminal Node Controller).
Using a simple modem, it is equipped with a function to prevent interference/collision during
communication by other stations, as well as functions to add a Frame Check Sequence
(FCS) to the transmission data provided and a flag data that indicates the packet frame
delimiter. 8 types of serial communication commands are available as an interface with
PCs.
3.2.2 TH-D74A/E Specifications
The TH-D74A/E supports packet speeds of 1200 bps and 9600 bps. The modulation
schemes used are AFSK for 1200 bps and GMSK for 9600 bps. The transmit and receive
buffer size is 3 kB and 4 kB respectively.
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