User's Manual

08RE398 TDFM-136B Installation Instructions
3.2 APPENDIX B - POST INSTALLATION EMI TEST INSTRUCTIONS
3.2.1 PURPOSE
The purpose of these tests is to identify any interference that the TDFM-136B may cause
with existing aircraft systems.
3.2.2 TEST CONDITIONS
The TDFM-136B transceiver should be installed and function tested. The antenna VSWR
should be checked. A forward/reverse power check with an in-line wattmeter should show
no more than 10% reflected power. For the following tests, insure that the power switch is
in the high position.
3.2.3 METHODOLOGY
Most of the EMI tests can be accomplished on the ground. In some cases flight testing is
required or is easier. If the aircraft is approved for IFR operations, then it is mandatory that
interference between the TDFM-136B Airborne FM and the approach aids be checked in
flight.
The GPS should be operational and navigating with at least the minimum compliment of
satellites. The VHF comm should be set to the frequencies indicated with the squelch
open. VOR/DME receivers should be set to the frequencies indicated and selected for
display. If possible, set up a DME ramp test set on the frequencies indicated and adjust
the output until the flags are out of view. The transponder and encoder should be
monitored with ramp test equipment. Set the output of the transponder test set to 3db
above the output necessary to achieve 90% reply. If possible set the ADF to a nearby
navigation station.
Modulate the TDFM-136B transmitter on the indicated frequencies for at least 20 seconds.
Observe the GPS for any degradation in satellite status or availability or flags. Listen for
any noise or detected audio signals on the VHF comm(s). Listen for any noise or detected
audio signals on the VOR/LOC receiver audio; look for any movement of flags or needles
on the VOR/LOC/GS navigation display(s). Observe the transponder for any loss of reply
or spurious reply.
List the power plant, fuel and other electric instruments in the chart provided and note any
anomalies that occur while transmitting. Assess the results.
If the aircraft is equipped with an auto-pilot or a stability augmentation system, then test fly
the aircraft and verify that operation of the TDFM-136B transceiver does not have adverse
effects on these systems.
After checking for gross effects at a safe altitude, fly an approach with each of the different
navigation systems coupled to the auto-pilot (ILS,GPS etc.) and look for any anomalies.
3-2 Technisonic Industries Ltd.