"Also, the radio is sold with 3, not 4 filters. Yes, the knob has 4
positions, but there are
only 3 filters installed as sold new."

JS Actually, no the R5000 came standard with a marginal 6khz filter
and a very nice 2.4khz filter. Most everyone bought the optional 6khz
filter which was much much better. A 1.9khz ssb and 500hz cw filter
could be added to the other slots, or other widths could be purchased
from outside vendors.