South Midlands Communications Group

Mobile NVIS Loop Antenna

NVIS Mobile Loop AntennaTraditional vertical 'whip' antennas fitted to vehicles for high-frequency communication suffer from a ‘skip zone’, where little or no communication is obtainable in a given area.

The SMC Mobile HF Loop Antenna, developed for NVIS (Near Vertical Incidence Skywave) communication across 3-15MHz, overcomes these limitations by having high radiation efficiency and no skip zone whatsoever.

Capable of automatically tuning across its frequency range in less than a 50th of a second, it is compatible with virtually any HF transceiver including frequency hopping types without the need for a separate control.

Based on the tried and tested SMC mobile NVIS loop which is in use by organisations throughout the world, this latest version incorporates a significant upgrade to ruggedized thick-walled tubing for performance and durability.

Other versions are available for:

  • Vehicle roof-bar fitment with a 'fold-down' facility
  • Side mounting on the vehicle.

The standard loop roof bar attachment is designed for roof bars 32mm x 22mm in cross section. However attachments can be manufactured to suit your individual requirement.

TX Power Input Range 1.5-200 Watts PEP
Continuous TX CW/Data Power 80W
Number of operating channels Unlimited
Non-Volatile Channel Memory Addresses 170 (165 TX, 5 RX)
Input Impedance Range 50 ohms
VSWR Typically less than 2:1 when tuned, (3:1 max)
DC Operating Range +10.0V to 18.5V DC, (+13.8 V DC nominal) 24V DC nominal also available on request
DC Current 230 mA average
Initial tuning response time (initial memory setting only) 2 - 20 sec per channel
Recurrent tuning response time (on-air use inc. freq hopping) Typically less than 10 ms per channel
Operational Temperature -35° to +70°C
Coaxial Cable RG58 5m in length
Power Cable 2 Core screened, 5m in length


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