As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HF RADIO NR 1 RECEIVES ONLY GARBLED TRANSMISSIONS. THE GROUND CAN HEAR OUR RADIO CALS ON HF NR 1, BUT WE CANNOT UNDERSTAND WHAT THEY ARE SAYING WHEN THEY REPLY. WE CAN HEAR THEM TALKING, BUT IT IS GARBLED. HF NR 2 WORKS FINE. GROUNDED - YES. ACCOMPLISHED AMM 23-11-00-730-801 HF COMMUNICATION SYSTEM TEST . CONTACTED SFO RADIO. TRANSMIT & RECEIVED VOICE TRANSMISSIONS CLEAR & LEGIBLE.