Stealth Telecom have recently developed an innovative broadband mobile antenna design for NVIS and made available a video on the web which features an Amateur Radio contact

NVIS refers to a radio propagation mode which involves the use of antennas with a very high radiation angle, approaching or reaching 90 degrees, using an appropriate frequency below the Critical Frequency.

It can provide reliable communications, without any skip zone, up to a distance of 350-500 km. NVIS works well with low power, is relatively free from fading and can even be used in valleys in mountainous areas.

The mode has been in use since the early 1940's but producing compact broadband HF antennas for mobile NVIS communications has always been a challenge. Stealth Telecom appear to have developed a compact solution to the problem.

Information, including a video, on the Stealth ST-940B Mobile NVIS Magnetic Loop Antenna is available on their website. Interestingly at 2:27 into the video there is a contact from A61AR in Dubai, United Arab Emirates using the ST-940B to a Cambodian Radio Amateur XU7TZG.

At a distance of 5360 km this really isn't NVIS but does illustrate what can be achieved with a small antenna just 1 metre above the ground.

Video of the Stealth ST-940B Mobile HF NVIS Magnetic Loop Antenna, Amateur QSO at 2:27 - http://stealth.ae/plugins/custompages/detinf.php?id=372&id_categories=136

ST940B Antenna Techical Notes - http://stealth.ae/plugins/custompages/articles.php?id=10

Wiki - Near Vertical Incidence Skywave - http://en.wikipedia.org/wiki/Near_Vertical_Incidence_Skywave

NVIS PowerPoint Slides - http://www.arrl.org/FandES/ead/materials/NVIS.ppt

Understanding Amateur Radio NVIS Antennas and Propagation - http://athensarc.org/nvis.asp

Patricia Gibbons WA6UBE - Tactical Link Systems - http://www.tactical-link.com/