ILS Marker Antenna – 17-4D/1

ILS Marker Antenna – 17-4D/1

The 17-4D is intended for airborne reception of ILS Marker signals at 75 MHz. When mounted on the underside of the aircraft, the antenna has maximum response to horizontally polarised signals within a cone having approximately + 45ยฐ boundaries. The operating bandwidth for the single frequency reception is sufficient to retain effective function within the degree of de-tuning to be expected from environmental variations.

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Specification

75 Minimum Frequency
75 Maximum Frequency
50 Impedence
< 1.5:1 - 75 MHz Return Loss VSWR
Not less than 16 dB below that of a half wave dipole at 75 MHz within a cone + 10ยฐ perpendicular to the antenna aperture when measured on a 6' circular ground plane (nominal) Gain
Horizontal (nominal) Polarization
0.95 Mass kg
50000 Altitude ft
54 Continuous Operating Temperature Min - C
90 Continuous Operating Temperature Max C