TECHNISONIC INDUSTRIES LIMITED
www.til.ca
TFM-550 Installation & Operating Instructions
TiL 99RE262 Rev A Issue 9
A-7
D.
The following procedure checks for second harmonic interference to the glide slope receiver
from the TFM-550. All transceivers produce harmonics (multiples of the wanted frequency)
and while the TFM-550 far exceeds FCC requirements, interference can still be experienced
depending upon antenna position and separation. Furthermore, harmonics can be generated
by other equipment in the aircraft and the structure of the aircraft where dissimilar metals
make contact or where grounds are isolated, etc. This is also true of aircraft hangers,
therefore testing should be done outside away from any structures where possible.
With a portable glide slope generator, provide enough signal to firmly activate the indicator
needle and hide all flags. Increase the signal level by 3 dB. Modulate the TFM-550
transmitter on the following frequencies for at least 20 seconds. Observe the Glide Slope
displays. Look for any movement of flags or needles on the navigation display. If an
interference condition is detected, then the installation will have to be flight tested
according to the following procedure: Using the table below, determine the glide slope
frequency based on the localizer frequency of the ILS to be used. Divide the glide slope
frequency by 2 and program into the TFM-550. Fly the aircraft to intercept the localizer and
glide slope (both needles centered) at 26 nm from the runway. Transmit on the TFM-550
for 10 seconds and watch for any deflections or flags. Repeat the test every 2 nm until the
indicators are not affected. If the distance is greater than 18 nm then a pass shall be
recorded. Otherwise the TFM-550 shall be placarded “Do not transmit while on ILS
approach”.
Localizer Glide
slope
Localizer Glide
slope
108.10
334.70
110.10
334.40
108.15
334.55
110.15
334.25
108.30
334.10
110.30
335.00
108.35
333.95
110.35
334.85
108.50
329.90
110.50
329.60
108.55
329.75
110.55
329.45
108.70
330.50
110.70
330.20
108.75
330.35
110.75
330.05
108.90
329.30
110.90
330.80
108.95
329.15
110.95
330.65
109.10
331.40
111.10
331.70
109.15
331.25
111.15
331.55
109.30
332.00
111.30
332.30
109.35
331.85
111.35
332.15
109.50
332.60
111.50
332.90
109.55
332.35
111.55
332.75
109.70
333.20
111.70
333.50
109.75
333.05
111.75
333.35
109.90
333.80
111.90
331.10
109.95
333.65
111.95
330.95
Содержание TFM-550
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