As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT NOT GROUNDED: PILOT REPORTS ANTI COLLISION LIGHT INTERFERRING WITH RADIO 1. BOTH SIDES HAVE A PULSING BACKGROUND NOISE THAT COINCIDES WITH TURNING ON OF ANTICOLLISION LIGHT. GOES OFF WHEN A/C LIGHT TURNED OFF. BOTH HEADSETS, 2 LEGS. MAINTENANCE REMOVED AND REPLACED UPPER ANTI-COLLISION LIGHT POWER SUPPLY IAW AMM 33-44-01. OPS CHECK GOOD. NO FURTHER NOISE NOTED.