[Elecraft] Re: K2 CW Filter Response Shape and Width

[Bill Tippett]

At 05:17 PM 7/1/03 -0700, Gary Hembree <hembree@asu.edu> wrote:

>Try looking at the data John, KI6WX obtained when he was evaluating a
>modification to the crystal grounding scheme in the K2 CW filter.  He
>measured the filter response by several methods, both in and out of the K2.
>  He includes graphs of the filter attenuation before and after the
>modification, from which you should be able to deduce the 6/60dB shape
>factor at a couple of bandwidths.  This data also shows that the "700Hz" BW
>is actually around 500Hz.  These measurements were done two years ago,
>before improved crystal matching was implemented by Elecraft.
>
>http://home.pacbell.net/johngreb/KI6WX.html
>
>73
>Gary, N7IR

         Thanks Gary!  Exactly what I was looking for and also a nice
explanation of Spectragram.  Sounds like these plots should now be
representative of standard K2 filters (post-3000 units) .  Still seems odd
that there was so little difference between selected 400 Hz and 700 Hz
filters (summary table on page 1).  Makes me wonder if the optimum
choices for selected filters should be spread over a higher range (e.g.
100, 600, 1200, 2000 Hz) than what some are using.

                                         73,  Bill  W4ZV