190-01499-02
GTX 3X5 Transponder TSO Installation Manual
Rev. 4
Page 6-40
6.12
Ground Check - GPS Reception Check
NOTE
If an external GPS is in use, GPS reception checks are not necessary.
The GPS check in this section is applicable to GTX 335 and GTX 345 units with an optional internal GPS
receiver.
1. Make sure the LAT/LON on the ADS-B Out page matches with a known reference.
2. Select 121.150 MHz on the COM transceiver to be tested.
3. Transmit for a period of 35 seconds.
4. Make sure the LAT/LON continues to match the known reference.
5. Repeat steps 3 and 4 for the following frequencies.
6. For VHF radios that include 8.33 kHz channel spacing, include the following frequencies in
addition to those in step 5.
7. Repeat steps 2 through 6 for all remaining COM transceivers in the aircraft.
8. Turn on the TCAS system and make sure the GPS position remains valid if the aircraft is TCAS
equipped.
9. Use the SATCOM system to make sure the GPS position remains valid if the aircraft is SATCOM
equipped.
• 121.15 MHz
• 121.22 MHz
• 131.22 MHz
• 131.30 MHz
• 121.17 MHz
• 121.25 MHz
• 131.25 MHz
• 131.32 MHz
• 121.20 MHz
• 131.20 MHz
• 131.27 MHz
• 131.35 MHz
• 121.185 MHz
• 130.285 MHz
• 121.190 MHz
• 131.290 MHz
