Cascaded filters, in two IF's, are essential for serious contest operation.
Also, if you want to add one additional 250 Hz filter, it should be in the 455
kHz IF, as that filter will have much better skirts than the 8 MHz one. Not
many transceivers will allow this, however. Some years ago, I built an
external filter box for the TS-930, which allows a 250 Hz filter to be
switched into the 455 kHz IF. It is cascaded with both the internal 500 Hz
filters, and provides skirt rejection comparable to the FT-1000D with both 250
Hz filters.
73,
Scott K9MA
--
Scott Ellington
sdelling@facstaff.wisc.edu
Madison, Wisconsin USA
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