Ham radio operators from the St. Croix Valley Amateur Radio Club in the Washington and Charlotte County area will be participating in a national amateur radio exercise from 2 p.m. on Saturday, June 22, until mid-morning on Sunday, June 23. The event is ARRL Field Day (www.arrl.org/FieldDay), an annual amateur radio activity organized since 1933 by ARRL, The National Association for Amateur Radio in the United States.