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15
OTHER FUNCTIONS
D
1200 bps packet operation
q
Connect the transceiver and a TNC as illustrated below.
w
Set the TNC for transmit.
e
Set transmit delay on the TNC to 30–50.
r
Adjust the TNC frequency deviation if necessary.
•
When using a deviation meter:
Adjust the output of the TNC so that frequency deviation
is in the range ± 3 to 4 kHz.
•
When NOT using a deviation meter:
A receiver or transceiver is needed to monitor the trans-
mission—compare the received audio output level when
receiving a TNC modulated signal with high level voice
signals using the microphone. Then adjust the TNC mod-
ulated signal to a lower level than the voice modulated
signal.
• Read the instructions supplied with your TNC carefully be-
fore attempting packet operation with the transceiver.
• Pin
t
AF OUT is for 1200 bps operation only. This pin
cannot be used for 9600 bps operation.
• Over modulation may degrade signal quality. If you find
that many transmissions are failing, re-adjust the modula-
tion level.
SQL
PTT
RX AUDIO
GND
TX AUDIO
TNC side
q
DATA IN
w
GND
e
PTT P
t
AF OUT
y
P SQL