[Elecraft] K2 Filter Shape Factors

[Eric Swartz WA6HHQ - Elecraft]

Hi Bill,

Above 1000 Hz you will see increasing ripple in the variable CW filter. At 1.2 
kHz and above it has significant ripple and a wider shape factor and is really 
only intended for tuning the band and casual SSB reception.

It is optimized for impedance match at around 400 Hz or so. It can be set 
wider for SSB receive, but is not optimal. For best SSB reception the fixed 
filter on the SSB board has a much better, flatter response :-)

73, Eric   WA6HHQ
------

Bill Tippett wrote:

> My point was to show that the 1.50 filter has a strange peak in the 
> passband
> that is actually narrower at S7 than the 700 or 400, yet that filter 
> then widens
> out down the skirts of the passband.  Has anyone ever posted a plot of the
> wide filters?  I'm just curious to know what they look like.
> 
>         The main point of my post was to ask what BW setting yields the
> best 6/60 dB shape factor.  From KI6WX's plots, it appears that the 400 Hz
> is better than 700 Hz, but I wonder what BW setting minimizes shape factor?
> 
>                                 73,  Bill  W4ZV