[TenTec] Effect of roofing filter selection on Orion II NB

[Grant Youngman]

> >Found that DSP NB performance was greatly improved by 
> >setting the roofing filter selection to 20 Khz, and also 
> > improved although less so at 6 KHz.


>          Which illustrates my previous point that there is 
> nothing NR does that turning BW down manually will not do 
> (and much faster).  

Except for the fact that I was talking about the NB and not NR :-)

To your point, I've come to the conclusion that while you're generally
correct, NR does add to SNR even at very narrow bandwidths.  I found in
testing that NR will improve the apparent (S+N)/N ratio around 10dB even at
100 Hz bandwidth.  Rough number, but it is bigger that breadbox .. :-)

Grant/NQ5T