In fact, 2.1 was one of the original possibilities for the TX filter and was removed. 73, doug From: "Don Cunningham" <wb5hak at martineer.net> Date: Fri, 8 Oct 2010 11:31:04 -0500 I agree, Bob, and wouldn't 2.1 kc make our transmit signal even cleaner?? I'm afraid I don't see the "status quo" either. 73, Don, WB5HAK