04/06/2016
ARRL Ohio Section Emergency Coordinator Stan Broadway, N8BHL, says he is hoping
to expand his section's "NVIS Antenna Day" on Saturday, April 23, by
encouraging participation by stations in neighboring states. This year's
activity also will offer the concept of establishing "anchor stations" around
Ohio to provide consistent signal reports to other participants. The
Near-Vertical Incidence Skywave or NVIS antenna has gained traction among
emergency communication groups and others desiring a close-in radiation pattern
for regional work on HF.
"Working with antennas has been an integral part of Amateur Radio since the
first hams took to the airwaves," Broadway said. "Having the 'right' antenna
becomes even more important when we're acting in the interest of public safety.
The Amateur Radio Emergency Service (ARES) organization in Ohio will put these
two concepts together in another NVIS Antenna Day." Getting under way at 1500
UTC on April 23, teams will begin making contacts to compare their antennas.
Stations do not need to operate from the field but the location should allow
room for several antennas.
"We don't have an ending time, because some stations had so much fun - and so
many pileups - last year that that they went on for quite a while past dark,"
Broadway recounted.
Broadways said several stations in surrounding states have indicated they plan
to be active in this year's NVIS Day. "We've also received word a group in
Texas will be doing their own NVIS exercise along with ours," he added. "So, it
looks like 40 meters will be busy with test signals!"
Broadway explained the "anchor station" concept this way: Team A puts together
a low-altitude G5RV, then contacts Anchor A in Toledo, Anchor B in Dayton, and
the Ohio Emergency Operations Center (EOC) station - know as "The Sarge" - for
signal reports. "They then either adjust their design, or try antenna number 2,
contacting the same anchors," he said. "From their signal reports, they can
determine right away which antenna is better and by how much."
Anchor stations' frequencies will be published, but participating stations may
contact as many other stations as they can find, allowing each station to plot
its coverage "footprint" to get a good idea of its capability for use in a real
emergency.
Broadway said NVIS Antenna Day is not a contest but an activity focused on
having teams or individuals research and determine the NVIS antenna designs
they believe will work the best - then build and test them on the air. After
the event all teams will file reports describing their antenna design and
indicating how they fared.
"Each station then can rank its top three antenna performers with comments and
ideas," Broadway said. "Pictures are very much encouraged." The sponsoring
Marion County ARES team will compile the documentation, and narrow down the
best-performing NVIS antennas across the region.
"The differences [among competing NVIS antennas] last year weren't as dramatic
as one might expect," Broadway said. "Those fashioned after the military
AS-2259 cross-dipole configuration appeared to be the best, but other designs
worked nearly as well," he pointed out. "We do understand that 'regular'
antennas work well also - a lot has to do with band conditions."
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