CREATE TABLE table_529 ("Branding" TEXT, "Callsign" TEXT, "Frequency" TEXT, "Power  ( kW ) " TEXT, "Location" TEXT)

What was the callsign in Zamboanga?
SELECT "Callsign" FROM table_529 WHERE "Location" = 'Zamboanga'
SELECT "Callsign" FROM "table_529" WHERE "Location" = 'Zamboanga'