CREATE TABLE table_5966 ("Callsign" TEXT, "Area served" TEXT, "Frequency" TEXT, "Band" TEXT, "On-air ID" TEXT, "Purpose" TEXT)

Frequency of 0 864 has what callsign?
SELECT "Callsign" FROM table_5966 WHERE "Frequency" = '0 864'
SELECT "Callsign" FROM "table_5966" WHERE "Frequency" = '0 864'