Chameleon NVIS portable antenna system, 160-6m

Near Vertical Incidence Skywave (NVIS) is a propagation mode in which signals are emitted almost directly upward with a high beam angle. The signals are then reflected back to earth, providing very effective short to medium range communications that work virtually every day into the evening.

The Chameleon NVIS is a specialized antenna designed primarily for NVIS propagation and emergency radio (EMCOMM) use. The typical use case for the CHA NVIS antenna is in a disaster area where communications are required with responders located outside the affected area, and the range of FM radios would not be sufficient.

The CHA NVIS antenna consists of crossed, tilted dipoles arranged at right angles to each other. It is designed to provide a near-vertical radiation pattern that allows close-range space wave propagation from beyond the radio horizon to about 500 km. 

At frequencies above 16 MHz, the radiation angle increases and the horizontal radiation pattern changes from predominantly omnidirectional to bidirectional. Although designed primarily for NVIS propagation, this antenna also provides satisfactory medium-range portable RF communications, especially at higher frequencies.

The CHA NVIS antenna operates from 1.8 - 54.0 MHz. We generally recommend the use of an antenna tuner, the antenna can then be used comfortably and without any adjustment in the entire frequency range. The mounting is done at a height of 5 meters, for example attached to a mast or suspended in a tree. The 4 elements, each consisting of antenna wire and guy wire, are simply tensioned down the side and attached to the ground with the included tent pegs. Each of these 4 elements has a total length of approx. 13.7 m. 

Assembly can be done quickly and easily on site by two people. All antenna wires and the guy lines can be wound up on the winders included in the set for transport and when not in use. Once on site, you can immediately start setting up the antenna, and tangled or knotted antenna wires are a thing of the past.

The antennas manufactured by Chameleon Antenna are versatile, reliable, unobtrusive and designed for long life.