Heat, wild frequencies blamed for storm siren activation
</element><element id="paragraph-1" type="body"><![CDATA[Wednesday's erratic activation of Harrisburg's storm sirens were apparently triggered by radio frequencies running wild due to atmospheric conditions brought on by extreme heat.
Chief Bill Summers said Walker Communications, the company that installed the sirens and maintains the city's radio systems, said the problem was not unique to Harrisburg; there were strange radio signals flying across Southern Illinois.
The storm sirens are triggered by a radio frequency. Under normal conditions the sirens can only be triggered locally. But in a period of hot stagnant air, the travel of radio frequencies can be unpredictable.
"Frequencies could come from a long way. Something can come through on the same wavelength and there it goes," Summers said.
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DeNeal receives e-mail at mailto:bdeneal@yourclearwave.com.</li>
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