User's Manual

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APPENDIX TO “INSTALLATION INSTRUCTIONS”
POST INSTALLATION EMI TEST
PURPOSE
The purpose of this test is to identify any interference that the TFM-500 may cause with existing
aircraft systems.
TEST CONDITIONS
The TFM-500 transceiver should be installed and function tested. The antenna VSWR should be
checked. A forward/reverse power check with a 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.
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 TFM-500 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 TFM-500 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 moment 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 autopilot or a stability augmentation system, then test fly the
aircraft and verify that operation of the TFM-500 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 autopilot (ILS, GPS ETC.) and look for any
anomalies.