Garmin GMA 342, Руководство по установке

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190-01878-02 GMA 342/345 Installation Manual
Rev. 5 Page 3-6
3.7.6 Speaker Check
1. If a speaker was installed, select SPKR and receive COM audio on the selected COM. When the
speaker is selected, the selected Receivers on the GMA 342/345 (COM, NAV, AUX) should be
heard from the speaker.
2. Initiate PA (Passenger Address) mode and verify that from both the pilot and copilot position, the
crew position that is pressing PTT has the respective mic audio delivered to the speaker clearly.
NOTE
If a loud squeal is heard while testing the PA, it is likely caused by acoustic feedback
between the speaker and the mic. Physically separating the speaker and microphone
should resolve this issue. If the speaker and mic cannot be placed sufficiently apart, a
lower volume configuration should be used. Some installations may not have sufficient
distance between the speaker and crew seat positions for reliable PA to speaker operation.
In these conditions, the “PA to speaker” volume can be set very low and PA audio will still
be delivered to the headsets.
CAUTION
Be sure to check all aircraft control movements before flight is attempted to ensure that the
wiring harness does not touch any moving part.
3.7.7 Marker Beacon Operation (if installed)
1. With a marker signal generator/transmitter test set, generate Marker Tones.
2. From the pilot headset position, verify that marker audio can be heard when selected.
3. If the system includes integrated lamp annunciation and/or if external lamps are installed, verify
that each marker tone illuminates the proper lamp.
NOTE
The Marker Lamps will operate even if the marker audio is not selected.
Outer Marker – Blue Lamp – 400 Hz (AM or received audio tone)
Middle Marker – Amber Lamp – 1300 Hz (AM or received audio tone)
Inner Marker – White Lamp – 3000 Hz (AM or received audio tone)
NOTE
To adjust the Marker beacon volume, put the unit into configuration mode as shown in
Section 2.8.6 , cycling to the Marker Beacon volume, then adjusting with the crew and pilot
buttons as described in Section 2.8.6 .
4. Verify that during HI SENS operation, the RF threshold is more sensitive (marker audio/indication
occurs as a lower RF power) when the GMA 342/345 is in HI SENSE.