NAVIGATION AND
COMMUNICATION
AIRPLANE
OPERATIONS
MANUAL
2-18-11
Page
6
Code
01
REVISION 31
• Direct COM Tuning
Direct COM tuning is accomplished by pressing and holding for
approximately 3 seconds the Line Select Button beside the COM
preset frequency line. The yellow cursor box will enclose the active
frequency, allowing direct COM tuning to that frequency, and the
preset frequency line will be blank.
To exit from direct COM tuning, press and hold the Line Select Button
beside the preset frequency line, until the preset frequency appears on
the COM window.
• Squelch Function
The COM squelch function is controlled through the Squelch Control
Button, labeled SQ, on the RMU control bezel. Pressing this button will
cause the COM radio to open its squelch and allow any noise or signal
present in the receiver to be heard in the Audio System. The squelch
open condition is indicated by the SQ label displayed on the top of the
COM window. Pressing the Squelch Control Button again will close the
radio squelch immediately.
• Automatic Time-Out
After approximately two minutes of continuous transmission, the
transceiver turns its transmitter off and a beep sound in the audio system
alerts the pilot to the fact. The transceiver then reverts to receiver mode
in order to prevent a stuck microphone button from blocking the
communications channel. Should the time-out occur, the pilot can reset it
by simply releasing the push to talk button and pressing it again.
To Next Page
