[Elecraft] filter alignment question

[Ron D'Eau Claire]

KT5D asked:
Everything seems to be fine except that as I scroll through the CW XFIL
filters, the tone of the test signal changes slightly. Is this to be
expected? Is it possible to get the tone exactly the same for every filter
setting or is a slight variation normal? 

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Yes, it is normal to have a slight variation although sometimes you "get
lucky" and it will be zero. What's happening is that when you select a
filter (FL1thru 4) digital data is being recalled from memory that is
converted into an analog voltage that tunes the BFO and VFO to the right
frequencies. The accuracy with which the analog voltage is generated is
limited by the Digital-to-Analog Converters (DACs). The DACs in the K2
provide a resolution of about 30 Hz. That is, the frequency can be as much
as 30 Hz different from the value that was originally set when the filters
were aligned. What you need to do to get it closer, if you can, is to repeat
the filter alignment procedure in the manual. Actually, you don't need to
repeat the whole setup, but simply cause the system to re-store new digital
data for the current settings. Information on now to do this is included in
the Builders Resources on the Elecraft web site. 

You may get a closer "match" or, if you are already within 30 Hz, it might
not be quite as good! 

Ron AC7AC