COMMUNICATIONS, UHF COM
Operation
Aircraft Operations Manual
4/6.2
O
PAGE
4
Apr 01/15
CONDITIONS
NORMAL PROCEDURES
2.8
MANUAL
FREQUENCY
SELECTION
The CHAN button is used to toggle the radio between manual and preset
channel selection. When a frequency is selected manually, semi
−
duplex op-
eration is not available. To enter a frequency manually:
1.
CHAN button (COM control unit)
PRESS
. . . . . . . . . . . . . . . . . .
−
Momentarily press the CHAN button until the channel number display (top
line) goes blank.
2.
Frequency selector
SET FREQUENCY
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
−
Rotate the small frequency selector knob to change the frequency in 25
KHz steps.
−
Rotate the large frequency selector knob to change the frequency in 1 MHz
steps.
2.9
COMMUNICA-
TIONS
Receiving
1.
UHF (COM 3) volume lever (ACP)
ADJUST
. . . . . . . . . . . . . . . .
−
Use headsets or hand microphones and loudspeakers
2.
Squelch
CHECK
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.
Volume knob (COM control unit)
READJUST
. . . . . . . . . . . . . . . . .
Transmitting
1.
XMIT SELECT
−
COM 3
SELECT.
. . . . . . . . . . . . . . . . . . . . . . . . .
−
Check button to be illuminating.
2.
PTT button
PRESS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
−
Check a TX to appear right of active frequency.
If both the guard and main receivers are active, the transmitter will operate on
the main receiver frequency. To transmit on the guard channel, it must be se-
lected first.
Do not transmit for more than 90 seconds. If the transmitter is active for more
than 90 seconds, a transmit timeout error occurs.
CAUTION