As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT FROM KSUU TO PHIK, HF NR 1 AND NR 2 RADIO REPORTED TO HAVE LOUD BACKGROUND SQUEAL AND IS UNREADABLE. CREW RETURNED AIRCRAFT TO KSUU AND LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED NR 1 HF ACCESSORY COUPLER AND NR 2 HF R/T. OPERATIONAL CHECKS WERE GOOD PER ALL APPLICABLE MANUALS.