Garmin GNS 530, Installation Manual

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500 SERIES INSTALLATION MANUAL Page 5-23
190-00181-02 Rev Q
5.3.6 VHF COM Interference Check
Once the Signal Acquisition Test has been completed successfully, perform the following steps:
1. View the Satellite Status Page and verify that 7 to 8 satellites have been acquired on the 500
Series unit.
2. Verify that the GPS “NAV” flag is out of view.
3. Select 121.150 MHz on the COM transceiver.
4. Transmit for a period of 30 seconds.
5. Verify that the GPS “NAV” flag does not come into view.
6. Repeat steps 4 and 5 for the following frequencies:
25 kHz COM channel spacing
x
121.175 MHz
x
121.200 MHz
x
131.250 MHz
x
131.275 MHz
x
131.300 MHz
8.33 kHz COM channel spacing
x
121.190 MHz
x
130.285 MHz
x
131.290 MHz
7. Repeat steps 3 through 6 for all COM transceivers installed in the aircraft.
8. If the GPS “NAV” flag comes into view, refer to Section 2.2.7 for options to improve
performance.
5.3.7 VHF COM Check (GNS 530 Only)
A flight test is recommended after the installation is complete to ensure satisfactory performance. To
check the communications transceiver, maintain an appropriate altitude and contact a ground station
facility at a range of at least 50 nautical miles. Contact a ground station in close proximity. Press the
squelch disable button to defeat the automatic squelch feature and listen for any unusual electrical noise,
which would increase the squelch threshold. If possible, verify the communications capability on both the
high and low ends of the VHF COM band. It may be required by the governing regulatory agency to
verify operation of the COM transmitter and receiver at the extents of a ground facility’s service volume
(e.g., FAA AC 23-8A).
5.3.8 VOR/ILS Check (GNS 530 Only)
Select a VOR channel within a 40 nautical mile range. Listen to the VOR audio and verify that no
electrical interference such as magneto noise is present. Check the tone identifier filter operation. Fly
inbound or outbound on a selected VOR radial and check for proper LEFT/RIGHT, TO/FROM, and FLAG
indications. Check the VOR accuracy. Verify that the flag is hidden with a valid received station, and that
the flag is in view when there is not a received station. It may be required by the governing regulatory
agency to verify operation of the VOR receiver at the extents of a ground facility’s service volume (e.g.,
FAA AC 23-8A).
5.3.9 DME Tuning Check (GNS 530 Only)
Select a VOR/ILS channel that corresponds to (1) a DME station within a 40 nautical mile range, or (2) the
frequency of a DME ground tester. Verify that the DME locks on to the signal and a valid distance,
ground speed and time are displayed.