What was found
HF NR 1 AND 2 COMMS VERIFICATION IN FLIGHT UNSUCCESSFUL. DUAL HF RADIO CHECK MADE ON FREQ 10057, REPORTED POOR FREQ TUNING AND 2 BY 3 RECEPTION AND TRANSMISSION. DUAL CHECK SUCCESSFUL. ACFT GROUNDED. REMOVED HF COUPLER NR 1 AND 2 TO CHECK OF HF ANTENNA FEED CONNECTIONS FOR CONDITION AND SECURITY IAW T/C NG-23EO-19805-1. REINSTALLED HF COUPLERS NR 2 IAW AMM 23-11-61-400-801, AND T/C NG-23EO-19805-1. PERFORMED HF NR 1, OPS CHECKED GOOD IAW AMM 23-11-00/501. PERFORMED HF NR 2 OPS CHECK GOOD IAW AMM 23-11-00/501. ETOPS GROUND VERIFICATION SUCCESSFUL.