Diversity reception in the SWL ranges, but that's hard core. ;o) Rick wa6nhc On 2/9/2015 7:11 PM, Milverton M. Swire via Elecraft wrote: >>>> A KBPF3 can be added to the main receiver, or the sub receiver, or both. <<< > What would be the advantage of adding KBPF3 to both the Main and the Sub? > > ((((73)))) Milverton / W9MMS