Emc Check - Garmin GTX 335 w GPS Installation Guidance

7.3.4

EMC Check

An EMC check must be conducted for each GTX after it is installed and all interfaces to external equipment
are verified to be correctly working. The EMC check verifies that the GTX is not producing unacceptable
interference in other avionics systems and that other avionics systems are not producing unacceptable
interference in the GTX. An example EMC Source/Victim matrix is shown in figure 7-1.
1. Enter equipment installed in the aircraft into the Source row and Victim column of the fillable form.
2. Apply power to all avionics systems except the GTX.
3. Verify all existing avionics systems are properly functioning.
4. Apply power to the GTX. (Connect a computer to the GTX 335 via USB before applying power to
the unit. Apply power to the GTX 335, then run the Install Tool.)
5. Remove power from all other avionics systems.
6. Apply power and/or operate the systems listed on the fillable form, one system at a time.
7. For panel mounted GTX 335 transponders: make sure there are not any active faults on the GTX.
8. Verify that each system functions properly.
For VHF COM radios:
a. Monitor one local frequency, one remote (far field) frequency, and one unused frequency.
b. Verify no unintended squelch breaks or audio tones interfere with communications
For VHF NAV radios:
a. Monitor one local frequency, one remote (far field) frequency, and one unused frequency.
b. Verify there are no guidance errors.
c. Verify no audio tones interfere with the station ID.
9. Repeat steps 6 through 8 until every system listed on the fillable form has been checked.
190-00734-17
Rev. 1
GTX 335 w/GPS Installation Guidance
Page 7-7