HF DF Loop Array


A crossed-loop/monopole direction finding antenna for use with Watson Watt method, with a large diameter of 2 m to achieve a high sensitivity. The loops make use of patented cross-polarisation cancelling technology that eliminates disturbances due to crosspolarisation from on-horizon sources. This offers enhanced, reliable accuracy in real-world applications and field trials over traditional crossed-loop designs. The antenna is collapsible for transport and storage. It is made of aluminium and brass elements and coaxial cable, with aluminium and composite mechanical parts. A lightweight composite quad pod supports the antenna above the ground. The quad pod collapses to a similar size to the antenna. The required matching, beam-forming and calibration injection circuitry is housed in the base of the antenna. A complete kit of parts including antenna, Quad pod, RF cables on drums, anchor stakes and alignment sight, is supplied with each antenna. The complete antenna and all accessories fit into the supplied shipping box.

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Frequency range 0.3 - 30 MHz
VSWR < 5:1 (over 90% of the band)
Nominal input impedance 50 O
Connectors 3 x N-type female
Feed power handling Receive only
Antenna gain at connectors See gain graph overleaf
Polarisation Vertical
Null depth > 15 dB
Omni pattern ripple < 3 dB peak-to-peak
Power consumption Zero (passive antenna)
ESD protection All metal parts grounded
Supplied cable matching < 5° difference at 30 MHz
Dimensions deployed 5.2 m tall
Dimensions collapsed 1750 x 185 x 185 mm (antenna) 995 x 300 x 300 mm (quadpod)
Weight of antenna < 30 kg

    Product Applications

    Signals Intelligence
  • Radio Direction Finding
  • C-ESM

    Design Features

  • Portable, deployable DF antenna High sensitivity Covers the whole HF band Patented cross-polarisation resistant technology Externally noise-limited ÔÇ? Passive antenna, no amplifiers to overload Waterproof Quad pod for mounting included Compact storage in supplied shipping box