The online DX magazine DXCoffee reports that an initial ham radio operation from South Sudan was on the air as of July 22, using the callsign ST0R and operating on 30 meters to start. (DXCoffee has recently started an English-language edition, in addition to its original Italian version. It's online at <http://www.dxcoffee.com/eng/>.)
The newly-established Republic of South Sudan is the latest addition to ham radio DX lists. It was added to both the ARRL's DXCC list and the CQ Countries list as of July 14, its admission date to the United Nations. Details will be in the September issue of CQ magazine.