As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOTH HF RADIOS ABILITY TO TRANSMIT HAVE DEGRADED OVER COURSE OF FLIGHT FOLLOWING INITIAL ATC COMM ESTABLISHMENT. ATC NO LONGER READS US. WE CAN HEAR THEM AT TIMES BUT RECEPTION VERY SCRATCHY. ACFT GROUNDED. REMOVED AND REPLACED L/H AND R/H HF COUPLERS IAW AMM 23-11-61-000-801. PERFORMED OPS CHECK OF LT AND RT HF COMMS IAW AMM 23-11-000-730-801. OPS CHECK OK. GROUND VERIFICATION SUCCESSFUL.