Yaesu FT-1000 Operating Manual page 37

4, Operation - Digital Modes: AMTOR, RTTY & Packet
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display the center frequency of the two transmitted
carriers, without any offset, in accordance with the
latest convention. However, for this to work properly,
you must set the PKT DIP switches in the top access
panel to match the tones generated by your tnc. See the
Packet DIP Settings Table on page 16.
Select the 500-Hz BANDWIDTH filter for 300-baud
packet, and press the PKT mode button on the front
panel once or twice, so that the green LSB LED indi-
cator lights along with the orange PKT LED.
Transmitter adjustment is similar to SSB:
¢ Preset the RF PWR control counterclockwise, and set
the METER selector to ALC.
* Now set your tnc to its "calibrate" mode, preferably
with both tones alternating, and adjust the MIC con-
trol so that the meter deflects to mid-scale.
¢ Switch the METER selector to PO and advance the RF
PWR control for the desired power output.
When tuning, bear in mind that some common hf
packet channels, such as "14.103" MHz, were original-
ly determined to correspond with an actual IF center
frequency 1700 Hz lower (in accordance with an old
TAPR convention). Therefore, if you have the DIP
switches set to match your tnc's actual tones, the dis-
play will show 14.101.30 when you are tuned to the
above frequency — which is the actual center of your
receiver passband, and the frequency mid-way be-
tween the two FSK carriers you will transmit.
Initially, you may need to adjust the receiver IF shift
a few clicks to the right or left to get the 500-Hz IF
filters perfectly centered over incoming signals. Start
RX ANT
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with the SHIFT control centered, and try to establish a
connection with a moderately strong signal on a clear
channel. If the connection is poor (many repeats), move
the SHIFT control one click to the right, and see if the
repeats decline. Continue in this manner until you find
a "sweet spot" (with minimal repeats) for the SHIFT
control, and make note of it. You will use this same
setting for all future hf packet operation.
1200-Baud FM Packet
The equipment setup for 1200-baud FM packet
(above 29 MHz) is the same as for 300-baud packet,
except that you may want to connect the squelch line of
the tnc to pin 5 of the PACKET jack if you plan to use the
squelch. Press the PKT mode switch unti: both it and the
green LED on the FM mode button are lit. Tuning is
much less critical in this mode, requiring no special
adjustments. Also, the FM MIC GAIN control in the top
access panel has been preset at the factory for proper
deviation with typical signal levels, so you should not
need to readjust it (you should adjust the t audio
output level of your tnc, though, if your signal sounds
distorted in the monitor).
To set up the transmitter for FM packet:
¢ Start with the RF PWR control counterclockwise, and
set the METER selector to ALC.
* Set your tnc to its "calibrate" mode, preferably with
both tones alternating, and adjust the DRIVE control
so that the meter deflects to mid-scale.
* Switch the METER selector to PO and set the RF PWR
control for the desired power output.
DATA DATA
PACKET
BUSY RX/TX OUT IN
g
Packet TNC Interconnections
page 35