TECHNISONIC INDUSTRIES LIMITED
www.til.ca
TDFM-9100 Installation Instructions
TiL 13RE483A
2-15
D.
The following procedure checks for second harmonic interference to the glide slope receiver from
the TDFM-9100. All transceivers produce harmonics (multiples of the wanted frequency) and
while the TDFM-9100 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 hangars, 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 TDFM-9100 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 TDFM-9100. Fly the aircraft to
intercept the localizer and glide slope (both needles centered) at 26 nm from the runway.
Transmit on the TDFM-9100 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 TDFM-9100 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
