What was found
RADAR TILT SEEMS TO SLOWLY DRIFT DOWN AFTER ABOUT 10 MINUTES OF USE. TILT UP HAS LITTLE EFFECT ON TOTALLY GREEN SCREEN IE +5 AT FL 380 IN CLEAR SCREEN. ALL GREEN TILT ON OR OFF WX T MAP NO CHANGE TURNING RADAR OFF FOR 5 MINS THEN ON. RADAR WILL WORK AGAIN BUT SLOWLY, TURNS GREEN AGAIN. ACFT GROUNDED. PERFORMED FIM 34-43, TASK 814, WEATHER RADAR SYS OPS TEST CHECKED GOOD WITH NO FAULTS. REPLACED WEATHER RADAR TRANSCEIVER REF 34-43-41. GROUND VERIFICATION TEST GOOD REF 34-43-41 & 34-43-00 WEATHER RADAR SYS OPS TEST.