w2aew, thanks for posting the video. I understand the basic description of how the filtering works with the up-converter, but I am lost in the details. I am by far not as knowledgeable in electronics as you. That being said, I have the same up-converter purchased from NooElec, and I am not having much luck receiving any HF signals through the SDR dongle. I wonder if some of my problem is that I live very near most of the TV and FM, transmitters in this area? I am also within 1 mile of a AM station as well. If this is my problem, can you suggest any additional filtering that may help.