NVIS Antennas

Dependable HF Coverage Within 400 km

For mobile use the choice seems to be a 16 ft whip, which is pulled down near the end, so it is parallel with the roof of the vehicle, making the signal go vertical. There are variations of this for permanent mobile antennas. It is recommended that the antenna be fully horizontal when not moving, if possible for best operation.

Fixed stations seem to have two options;

  1. Dipole antenna for 40m and 80m with a 15 ft insulated mast in the centre.
    Design Guide: http://www.vcars.org/tech/NVIS.html
    Same design, but more details on the mast: http://webpages.charter.net/w9wis/NVIS1_nn4.html
    Buddipole N-Vee Antenna (more good ideas) http://www.w0ipl.com/ECom/NVIS/cbp-nvis.htm
  2. Tri-band dipoles for 40m, 60m, 80m
    Similar design, but tri-band 40m, 60m, 80m http://www.commacademy.org/2004/handouts.php (This is a large PowerPoint presentation)
  3. Wire antennas located very close to the ground, either fed from the vehicle antenna mount or from a portable radio
    Examples with user results: http://www.tactical-link.com/field_deployed_nvis.htm