Garmin GMA 342, Руководство по установке

Страница: 24 / 65

190-01878-02 GMA 342/345 Installation Manual
Rev. 5 Page 2-8
2.7 Cooling Air
The GMA 342/345 does not have provisions for attaching cooling air, however the thermal characteristics
of the installation should always be assessed. An undesirable thermal condition could be created due to the
unit's own internal power dissipation combined with restricted ventilation, or due to heat generated by
adjacent equipment. Limiting thermal build up, by means of fan or natural convection is always a good
practice and recommended to increase the product life.
2.8 Configuration, and Adjustment Options
The GMA 342/345 has several configuration/adjustment options (see Section 2.8.6 ). These configuration/
adjustments are as follows:
• Wired Telephone Volume
• Auxiliary 1 Volume
• Auxiliary 2 Volume
• Auxiliary 3 Volume
• Alert 1 Volume
• Alert 2 Volume
• Alert 3 Volume
• Alert 4 Volume
• Speaker Volume
• Marker Beacon Volume
• Passenger Address Voume
• Master Avionics Squelch ( Section 2.8.1 )
• Marker Beacon Low Sensitivity Offset ( Section 2.8.2 )
• Marker Beacon High Sensitivity Offset ( Section 2.8.2 )
• High Cockpit Noise Option ( Section 2.8.3 )
• Music In Isolation Option ( Section 2.8.4 )
2.8.1 Master Avionics Squelch (MASQ) Function
MASQ functions to prevent low level noise from being passed to the headset ear speakers, this is known as
“squelching” or muting the audio. To “break” or “open” squelch means that enough audio signal is present
that the signal is passed through and can be heard. Increasing this setting increases the signal level
required to break/open squelch. If needed, adjust the MASQ SQ level so the audio background noise is
muted.
2.8.2 Marker Beacon Sensitivity Offset
Sensitivity Offset From Calibration. At default offset level, marker sensitivity is calibrated to 200 uV for
high sensitivity mode and 1000 uV for low sensitivity mode. Adjust up (right) if more sensitivity (earlier
indication, longer lamp dwell over beacon, lower threshold voltage) is desired. Adjust down (left) if less
sensitivity (later indication, shorter lamp dwell over beacon, higher threshold voltage) is desired. The low
and high sensitivity settings are independent and do not affect each other.
2.8.3 High Cockpit Noise Option
Enable to help reduce intercom background noise in very high noise cockpit environments. Disabled by
default.
2.8.4 Music In Isolation Option
Enable to allow pilot and copilot to hear selected music when PILOT or CREW isolation mode is active.
Disabled by default.