P/N 11934-S01
7 of 10
Cirrus Design
Section 9
SR20
Supplements
•
Right Outer Knob
– Copilot and passenger mic VOX level. CW
rotation increases the amount of mic audio (VOX level) required
to break squelch. Full CCW is the ‘hot mic’ position.
Each microphone input has a dedicated VOX circuit to assure that only
the active microphone(s) is/are heard when squelch is broken. After
the operator has stopped talking, the intercom channel remains
momentarily open to avoid closure between words or normal pauses.
Control
The Audio Control Panel provides an adjustable Voice Operated Relay
(VOX) Squelch Control for the pilot, copilot, and passengers. Since the
VOX circuits reduce the number of microphones active at any one
time, the amount of unwanted background noise in the headphones is
diminished. This also allows the use of dissimilar headsets with the
same intercom. Because the user can adjust the trip level of the VOX
squelch to fit the individual voice and microphone, this helps eliminate
the frustration of clipping the first syllables. There is a slight delay after
a person stops talking
before the channel closes. This prevents
closure between words and eliminates choppy communications.
To adjust squelch:
1.
With the engine running, set the VOX trip level by slowly rotating
the SQL control knob clockwise until you no longer hear the
engine noise in the headphones.
2.
Position microphone near your lips and speak into microphone.
Verify that normal speech levels open the channel.
Intercom Modes
The GMA 340 provides three intercom (ICS) modes to further simplify
workload and minimize distractions during all phases of flight: PILOT,
CREW, and ALL. The mode selection is accomplished using the
PILOT and CREW push-buttons. Pressing a button activates the
corresponding ICS mode and pressing the button a second time
deactivates the mode. The operator can switch modes (PILOT to
CREW or CREW to PILOT) by pressing the desired modes push-
Revision 1: 07-18-05
