Tod, KD7EFQ wrote: "I was told at Dayton that Inrad filters don't "Ring" as much as TT filters. Any help is appreciated." ========== You will hear any narrow CW filter will "ring" if you have your sidetone/spot pitch (i.e., CW offset) set too high. Set it at a lower pitch and you won't hear the "ringing". 73, de Earl, K6SE