Installation Instructions

GTN 6XX/7XX AML STC Installation Manual 190-01007-A3
Page 5-92 Rev. 4
5.7.4 VHF NAV Checkout (GTN 650/750 Only)
Touch the CDI key to select VLOC mode, which is indicated by a green ‘VLOC’ annunciation on the
bottom center of the display. Check the VOR reception with ground equipment, operating VOT or VOR,
and verify audio and Morse code ID functions (if possible). Tune a Localizer frequency and verify the
CDI needle and NAV flag, and VDI needle and GS flag operation.
5.7.4.1 NAV Audio Check (For non-GMA 35 Installations)
1. Ensure the audio panel is powered on.
2. Plug in a headset at pilot and copilot position.
3. Tune the GTN NAV receiver to a local VOR station.
4. Ensure the Morse code identifier is being received over the crew headsets.
5. If the audio is not heard, verify the wiring connections to the audio panel.
6. Ensure the audio volume is sufficient for all anticipated cockpit noise conditions.
7. Repeat steps 2 through 5 for each installed GTN NAV receiver.
5.7.5 VHF COM Checkout (GTN 635/650/750 Only)
5.7.5.1 Antenna Check
If desired, the antenna VSWR can be checked using an inline wattmeter in the antenna coaxial using
frequencies near both ends of the band. The VSWR should be < 2:1. A VSWR of 2:1 will cause a drop in
output power of approximately 12%.
5.7.5.2 Receiver/Transmitter Operation
Tune the unit to a local VHF frequency and verify the receiver output produces a clear and
understandable audio output. Verify the transmitter functions properly by contacting another station and
getting a report of reliable communications.
5.7.6 GMA 35 Audio Panel Checkout (GTN 7XX Only)
5.7.6.1 GMA 35 Interface Check (GTN 7XX Only)
1. With the GTN running and the GMA 35 audio panel powered on, go to the Home page and touch
the Audio Panel key.
2. Ensure that a red ‘X’ is not displayed over the Audio Panel key.
After configuring the audio panel, an in-aircraft checkout may be performed with a good microphone,
headset, speaker, and avionics receivers. For testing the marker beacon, use a ramp tester that transmits a
75 MHz marker beacon test signal, or perform the flight check outlined in Section 5.8.7.
For instructions on how to operate the GMA 35 in normal mode during the installation checkout
procedures, refer to the GTN 7XX/GMA 35 Pilot’s Guide, P/N 190-01007-03. Verify that every function
of the GMA 35 operates correctly. Ensure that the GMA 35 circuit breaker is pressed in and is receiving
power.
NOTE
In the following procedural steps outlined below, allow for variation in the
configuration settings for the particular installation under test.