[MrFixr55]

Check the power supply for the ATSC / NTSC convertor or other input. Had an experience yesterday with a wireless mic receiver. There was a 120 Hz hum when potting up the input that the wireless mic receive was connected to. The culprit was the 12VDC analog "Wall Wart" power supply for the wireless mic receiver. replacing it with a switching PS resolved the issue. And yes, between the CFL and LED lights, the the computers, WiFi, the IOTs (Internet of Things), the remote read electric meters, etc., etc., etc., itis almost impossible to receive AM (and analog TV Video is AM)