[Elecraft] K3: Choosing which filters to buy

[Craig D. Smith]

Shane ...

The most cost effective general purpose CW filter is the 500 Hz. I have one
and would recommend it.  For most everyone, the difference in shape factor
between the 5 pole and the 8 pole filters will not be a practical issue with
the DSP filtering.

However, please be advised that relatively recent new twists have been
added.  It now turns out that if you are interested in either diversity
reception with the K3 sub receiver or in using the N8LP panadapter
accessory, there may be advantages in using only 8 pole filters.   It has to
do with the variable offsets of the 5 pole filters.  I'm not knowledgeable
enough about either diversity or panadapters to understand the nuances, but
if you intend to use either of these capabilities you may want to go with
the more expensive 8 pole filters.

                         ... Craig   AC0DS