I have used the Autech VA1 unit and it works great outside of BC band AM station influence. For example, it worked fine at an antenna farm about 6 miles from WBCK - 5KW days on 930. At my house, only 1/2 mile from same station, it is impossible to read anything meaningful. I am glad to hear that MFJ is now making a tunable filter for their unit(s) George K8GG