This product comes from Alaris Antennas catalogues

DF and Monitoring Stack


The SYST-A0004 is an antenna stack comprising DF-A0038 vertical polarisation DF and Omni, and OMNI-A0099 and OMNI-A0100 horizontal omni antennas. At the base it is supported by the MISC-A0047 support cage. All RF and control signals pass through the MISC-A0045 amplifier block which compensates for cable losses. Mounted on a mast, with vertical and horizontal polarisation monitoring, and interferometric direction finding, it provides a complete spectrum monitoring and DF solution. A DF switch can be mounted at the base of the DF array. Its cables can be fed back into the mast and routed through the omnis. The horizontal-polarisation omni antennas feature a cable duct for connection of antennas above, without distortion of their patterns. All monitoring antennas share a common axis, giving excellent radiation patterns.

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Frequency range 20 - 3000 MHz
Polarisation Vertical
Nominal input impedance 50 O
Connectors 15 x TNC-M on cables
Cable exit Standard flange for switch mounting
Power supply requirements DC 15±1 V
Dimensions Ø2.6 m x 5.5 m
Total mass 125 kg
Internal joining Bolted flanges
Mounting method Flange mounted 8 off 12 mm holes on 280 mm PCD
Wind survival 160 km/h (without ice)
Effective wind area 1.8 m 2 (including DF switch)
Temperature (operational) -30 °C to +70 °C
Temperature (storage) -40 °C to +71 °C

    Product Applications

    Signals Intelligence
  • Radio Direction Finding
  • C-ESM

    Design Features

  • Three-band direction finding array optimised for two-channel receivers. Hinge mounting flange for DF switch, with cable re-entry port. Vertical and horizontal monitoring. Concentric design eliminates shadowing.