[Elecraft] KX3 Roofing filter question

[Fred Jensen]

Joshua,  Probably not.  The ultimate BW of your receiver is set by the 
DSP and noise power is "sort of" proportional to BW.  The purpose of the 
roofing filters is to protect the ADC sampler at the head end of the DSP 
from very strong signals that could drive it to saturation.

Noise, other than atmospheric and galactic, needs to be attacked at the 
source.  Like getting rid of your switching wall warts and power 
supplies.  So long as the atmospheric noise is not saturating the ADC, 
reducing the DSP BW is the only really effective way to reduce it's 
impact, and that's a lot easier on CW than on SSB.  Different roofing 
filters are not likely to make much difference at all unless they're 
more narrow than your DSP setting.

On 3/24/2015 7:24 PM, Joshua Gould wrote:
> All,
>
> Would the roofing filters help reduce atmospheric noise?  I'm having a heck
> of a time hearing anything over the S5 noise levels that I seem to be
> dealing with of late.  But at least it's better than the S9 noise I was
> getting from switching power supplies under my desk...
>
>
> 72,
> Joshua Gould
> K8WXA
> EM89pn