From time to time I do pick up a low intermittent hum on the feed.....the possible reason for this is the layout of the feed system in my home....There is quite a long lead coming from the high gain scanner into the computer. This long lead is necessary as I keep the reciever at the closest point possible to the antenna to avoid signal loss ..although I do use expensive low loss coax cable coming from the 5 element yagi .The yagi is over 20 feet off the roof to get a good path to EIDW...see setup pics M50