Table schema:
CREATE TABLE table_12379297_1 (coverage__transmitter_site_ VARCHAR, callsign VARCHAR, station_type VARCHAR, power__kw_ VARCHAR)

Question: What is the coverage of relay 5kw of dyfj-tv?
SQL: SELECT coverage__transmitter_site_ FROM table_12379297_1 WHERE station_type = "Relay" AND power__kw_ = "5kW" AND callsign = "DYFJ-TV"