[Elecraft] K2: KAF2 Versus 2.2 kHz KSB2

[Dale Boresz]

Hello Michael,

I like the characteristics of the passive filter used on the KAF2, so I 
removed the components and used them to build the same circuit which I 
placed at the output of my KDSP2 module. I am using KI6WX's 2.5 kHz 
bandwidth mod, and am very pleased with the results. However, as John 
himself stated, you should be sure to place switch S1 on the KAF2 into 
the 'Bypass' position when using Spectrogram to make measurements, to 
avoid the additional rolloff.

73, Dale WA8SRA

Linden, Mike (BRC-Hes) wrote:

>  I plan on building my KSB2 to KI6WX's 2.2 kHz crystal filter bandwidth
>specifications (which is now the current Elecraft bandwidth). Should I shift
>the KAF2's low-pass filter roll-off higher in frequency when I build it to
>account for the increased bandwidth of the KSB2, or will the low-pass
>roll-off be adequate as is?
>
>  Thanks, Michael N9BDF
>  K2 #4137
>
>
>  
>