From Jerry Berg’s book, “Listening on the Short Waves, 1945 to
Today"

"Inaugurated in September 1966, the Flash Sheet was a two-page column of
'hot' information from both NASWA members and others. Prepared at the
outset by Bill Eddings, it was assigned its own editor, Al Niblack of
Vincennes, Indiana, in November 1967."

"Also in January 1973 a separately mailed, mid-month Flash Sheet was
introduced to supplement the monthly in-bulletin Flash Sheet.  (The
latter went to separate mailing as well in 1974 but returned to in-bulletin
status in May 1975.)  Called DX Hotline, Update and DXtra at different
times over the years, the Flash Sheet continued under various editors until
1989 (and was resurrected in electronic form in 2001)."

Editors (print):
Bill Eddings, Altoona, Pennsylvania (1966-67)
Al Niblack, Vincennes, Indiana (1967-1975)
Ralph W. Perry, Libertyville, Illinois (1975-1976)
John J. Moritz, Jr., Youngstown, Ohio (1976-1977)
Thomas B. Alleman, Kansas City, Missouri (1977-1986)
Robert J. Hill, Sharon, Massachusetts (1987-July 1989).   

The Flashsheet went electronic in December 2001.  
Editors:  
Sheryl Paszkiewicz, Manitowoc, Wisconsin (2001-2004)
Ray Bauernhuber, Whitestone, New York (2004-2006
Mark Taylor (2006 to present).