I Packet (Afsk) Operation - Icom IC-7400 Instruction Manual

I Packet (AFSK) operation

Before operating packet (AFSK) be sure to consult the
operating manual that came with your TNC.
q Connect a TNC and PC. (p. 77)
w Push a band key to select an operating band.
e Push [SSB] or [AM/FM] to select the desired operat-
ing mode.
• After LSB or USB is selected, push [SSB] for 1 sec. to
select LSB data or USB data mode, or after AM or FM is
selected, push [AM/FM] for 1 sec. to select AM data or
FM data mode.
• Generally, LSB is used on HF bands and FM is used for
packet operation on the VHF band.
r Rotate the tuning dial to tune the desired signal.
t Transmit your AFSK signals using your computer's
keyboard.
• Rotate [RF PWR] to set the output power.
• Relative strength of the transmitted signal is indicated in
the Po meter while operating the TNC.
• When operating in SSB (data) mode, adjust output
power so that the ALC reading in the ALC meter stays
in the ALC zone.
NOTE: When connecting a TNC to the ACC socket
on the rear panel, select SSB (LSB/USB) data mode
or disconnect the microphone and rotate [MIC
GAIN] fully counterclockwise.
When SSB data mode is selected, the audio input
from the [MIC] connector is automatically cut, and
the audio input from the [ACC(1)] is used.
Also, when the SSB data mode is selected, the fixed
setting listed below are selected automatically;
• Speech compressor : OFF
• Transmit bandwidth : MID
• Tx tone (Bass)
• Tx tone (Treble)
D D
Frequency indication during AFSK operation
When operating AFSK in SSB mode, the indicated fre-
quency is the signals carrier point.
: 0
: 0
DATA COMMUNICATION
[TRANSMIT] [TX] indicator
[MIC GAIN] [SSB] [AM/FM] Tuning dial
Selected mode indicator appears
• Example— LSB/LSB data mode
Mark freq.: 2125 Hz
Shift freq.: 200 Hz
2325 Hz
200 Hz
10
Band keys
2125 Hz
Carrier point
(Displayed frequency)
78