[Elecraft] K2 Filter Alignment: USB vs. LSB, CW vs. CW-Rev

[Rich Lentz]

>> Actually there is no real connection between hearing the same pitch when
switching between LSB and USB and proper filter alignment like there is with
CW and CWr.

This explanation has me confused. The description on page 102 (Rev c) gives
me the impression that the K2 shifts the BFO relative to the passband for
BOTH USB and CWR (17 M & below). This also agrees with my observations. 

I have found that I have had to change the passband by one or to digits to
get a good compromise between desired passband and alignment of received
frequencies, that is W1AW and WWV does not move as you select different
XFIL.  I do not have this problem on CW and LSB (again, 17 M & below) as the
BFO numbers (See table 8-1) are all the same.  This BFO number [for CW and
LSB (again, 17 M & below)] also agrees with the number you get using the
N6KR method.  For weak signal digital modes where I want to use the XTAL
filters I will use LSB for 17 and below and USB on 15 and above to minimize
this shift and the resultant "signal creep" from the other end tracking my
shift.

There is an Excel Spread Sheet that helps you get in the ballpark for these
BFO settings on the Elecraft Web Page.

Rich
KE0X