CREATE TABLE table_50345 ("Callsign" TEXT, "Area served" TEXT, "Band" TEXT, "Freq currently" TEXT, "Purpose" TEXT)

What is the Purpose of the Callsign with a Freq currently of 4gld?
SELECT "Purpose" FROM table_50345 WHERE "Freq currently" = '4gld'
SELECT "Purpose" FROM "table_50345" WHERE "Freq currently" = '4gld'