What was found
HF NO 1 APPEARS TO BE UNUSABLE/INOPERATIVE RECEPTION IS UNREADABLE AND TRANSMISSIONS GO UNANSWERED ON ALL FREQUENCIES. GROUNDED - YES. PERFORMED BITE TEST ON HF 1 AND HF2, HF 1 FAIL, SWAPPED, HF1 AND HF2 TO TS, HF1 FAILS. SWAPPED HF1 AND HF2 TO ORIGINAL POSITION BITE TEST GOOD ON BOTH SYSTEMS, NO TRANSMISSION STILL AND RECEPTION GARBLED. R&R HF1 COUPLER IAW B737-9 AMM 23-11-61/401. HF1 AND HF2 TRANSMISSION AND RECEIVER TEST GOOD.