TECHNISONIC INDUSTRIES LIMITED
www.til.ca
TDFM-7300 Installation & Operating Instructions
TiL 08RE389 Rev A Issue 4
3-9
3.19 POST INSTALLATION EMI TEST
PURPOSE
The purpose of this test is to identify any interference that the TDFM-7300 transceiver may
cause with existing aircraft systems.
TEST CONDITIONS
The TDFM-7300 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 output power is
set to high.
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-7300 transceiver 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-7300 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 TDFM-7300 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.
