eHam.net News for Tuesday 28 June 2016
 

eHam.net News

///////////////////////////////////////////
Amateur Emergency Radio Services Participates in Field Day:

Posted: 27 Jun 2016 05:16 PM PDT
http://www.eham.net/articles/37060


The American Radio Relay League, or ARRL, kicked off its annual Field Day
event Saturday as North American radio operators began spinning and
grinning - radio lingo for signal scanning across a frequency band. The
event is a 24-hour scored event where teams attempt to contact as many
other stations as possible through any of their communication modes.
Operators communicate with Morse code, digital teletype and, of course,
voice. "It's called Field Day because we get out and set up in the field
where we aren't usually operating," Kevin Kingery, of North
Augusta-Belvedere Radio Club, said. "It's meant to get out and practice in
case of an actual emergency, like hurricanes or tornadoes taking out
electricity and phone communications."


///////////////////////////////////////////
Seeing Sunspots as Early Astronomers Did:

Posted: 27 Jun 2016 05:15 PM PDT
http://www.eham.net/articles/37059


Astronomers have reconstructed 18-century telescopes to observe sunspots
and better understand solar cycles. Astronomers have been counting sunspots
-- the most accessible tool they've had to measure solar activity -- for
the past 400 years. In more recent times, technology has advanced, making
it easier to pick out smaller sunspots or even measure the magnetic field
directly. But some astronomers are now turning back the clock. They're
reconstructing ancient telescopes to observe sunspots as our forebears did
to better understand the Sun's evolution. Sunspots are irregular shapes on
the surface of the sun; the cooler gas, held still by strong magnetic
fields, appears dark against the rest of the boiling-hot surface. The more
sunspots, the more magnetically active the Sun is. Sunspot observations
through the centuries have shown two long-term trends in the Sun's
activity: a possible 100-year cycle and a long-term increase in sunspot
number. However, it turns out this second trend isn't real -- it's due to
inconsistencies in sunspot-counting. A team led by Leif Svalgaard
(Stanford) built 18th-century telescopes to count sunspots and record the
evolution of the solar cycle in the same way as astronomers from
yesteryear. The behavior of the solar cycle is crucial to studying solar
dynamics, forecasting space weather, and modeling climate change. Our
general understanding of the Sun relies on our knowledge about its past
behavior.