MILWAUKEE (AP) – Journal Communications Inc. says its third-quarter earnings increased 73 percent on the strength of political and issue ads in its broadcast business.   The Milwaukee-based company owns Wisconsin’s largest newspaper, the Milwaukee Journal Sentinel. But it also owns 14 TV stations and 35 radio stations in 12 states.   The company reported net earnings Thursday of $7.7 million, or 14 cents per share. That’s up from earnings of $4.4 million in the year-ago quarter, or 7 cents per share.  Journal Communications had total revenue of $97.8 million, an 11 percent increase.  CEO Steven Smith says broadcast revenue rose 25 percent, driven by political and issue ads and also the summer Olympics on the company’s NBC stations.  The company expects broadcast revenue to increase 25 percent next quarter from continued political advertising.