Historical clue formulations

• PBS station in the Big Apple — 2015-11-15
• PBS station behind "Live From Lincoln Center" — 2014-11-18
• N.Y.C.'s PBS station — 2013-05-03
• PBS flagship station — 2012-01-15
• N.Y.C.'s PBS station — 2011-08-05
• PBS flagship station — 2010-03-07
• PBS station with a transmitter on the Empire State Building — 2009-01-16
• PBS station behind Charlie Rose — 2007-09-08
• Big letters in public broadcasting — 1998-02-01