CREATE TABLE table_75032 ("Call sign" CLOB, "Analog channel" CLOB, "Digital channel" CLOB, "Virtual channel" CLOB, "Network" CLOB, "Station Ownership" CLOB)

Network of nbc is what digital channel?
SELECT "Digital channel" FROM table_75032 WHERE "Network" = 'nbc'
SELECT "Digital channel" FROM "table_75032" WHERE "Network" = 'nbc'