What was found
WXR GENERATED RANDOM SPIKES ON BOTH DISPLAYS AT RANGES GREATER THEN 40 MILES. GROUNDED YES. UNABLE TO DUPLICATE. DUE TO HISTORY REMOVED AND REPLACED WXR R/T OPS TEST GOOD REF MM 34 43 41 400 801. VERIFICATION FLIGHT FAILED. REMOVED AND REPLACED WXR DRIVE UNIT REF 34 43 11. DURING REMOVAL / REPLACEMENT NOTED LOOSE FOREIGN MATERIAL INSIDE OF THE SEALED PORTION OF THE WAVE GUIDE THAT IS ATTACHED TO THE DRIVE UNIT. AIRCRAFT SIDE WAVE GUIDE NO DEFECTS NOTED. WXR OPS TEST CKS NML REF M/M 34 43 00. VERIFICATION FLIGHT SUCCESSFUL.