If the world's communications system fails, who will you call?

No one. That's the problem, according to Warren Appel, an amateur radio operator in Casper.

In the event of an emergency, amateur radio operators, or "hams" as they're better known, could be the only people able to communicate across the country and around the world.

Beginning at noon today and running until noon on Sunday, Casper hams will set up and operate field radio stations on the Kelly Walsh High School practice football field to contact other hams throughout the United States and Canada as part of the American Radio Relay League's annual Field Day.

"The last week in June, we pack up our radios and go talk to people all over the place. This field day is part of a nationwide thing," Appel said. "Some hams do it in their homes, but some go out to remote locations and put our equipment up in less than ideal circumstances."

It's not all in preparation for an electronic communication doomsday scenario - it's also, of course, for fun.

"If stuff just hit the fan, can we still make this work? We need to show that if the infrastructure here failed, we could still talk to Texas, or to back East somewhere," Appel said. "It puts us in a public arena where every-day Joes can come out and see what it is we do."

Attendees will be able to see any and all of amateur radio's communication modes in action, including voice, code, packet radio, teletype and satellite.

In the past, trained amateur operators have effectively established emergency communications nets during floods, fires, blizzards, tornadoes and other major disasters, including the events of Sept. 11, 2001, Appel said. Using generators and battery power, the group is able to set up antennas and quickly make communication available.

This year, the hams will also offer a 24-hour amateur radio testing session for individuals interested in testing for their first amateur radio licenses.

"It's a huge, fun event for hams. Over the years, [the field day] has evolved into an on-air contest, to see who can make the most number of contacts," Appel said. "And if people are interested, they should just come out and see it. People walking in off the street, if they want to, they can come out and test a radio."

Contact reporter Megan Lee at (307) 266-0616 or megan.lee@trib.com.