[Elecraft] K3 SSB filters

[David Gilbert]

No, the roofing filters aren't superfluous even with lower level 
signals.  If you set the bandwidths similarly as I do all of the time, 
the rejection of the filter adds to the rejection from the DSP.  I think 
this should be pretty obvious.

Dave   AB7E



On 3/31/2020 8:36 PM, Don Wilhelm wrote:
> Hopefully that we will remember that the DSP filter skirts are steeper 
> than the crystal filter skirts, so judicious use of the HiCut and 
> LoCut will provide us with a better passband than narrow roofing filters.
>
> What the roofing filters will do is keep the receiver from reducing 
> the hardware AGC for stations which are within the roofing filter 
> passband.
> It takes adjacent signals in excess of S-9 +30 for the adjacent signal 
> to activate the hardware AGC (which protects the front end DAC from 
> overload).  If the interfering station does not exceed that threshold, 
> then the DSP filters will take care of it, and the need for more 
> narrow roofing filters is superfluous.
>
> 73,
> Don W3FPR