[Elecraft] 200 Hz 5-pole filter

[Jim Brown]

On Sun,7/26/2015 5:33 PM, Bill Breeden wrote:
> The point I am trying to make is that a K3 with a 2.7 KHz filter and 
> the DSP cranked down to 400 Hz will not perform as well for CW during 
> crowded band conditions as a K3 with a 400 Hz filter. 

Hi Bill,

That point is not lost on anyone, and is the reason that serious 
contesters use narrow roofing filters. I said exactly that in my earlier 
response.  But the point that you are missing is that the K3, K3S, and 
KX3 are complete radios with the stock 2.7 kHz 5-pole or 2.8 kHz 8-pole 
roofing filters, and are comparable to the receivers we have used for as 
long as I have been a ham (60 years).

What's different are 1) the some of the hardware with which those older 
radios and the K3/K3S/KX3 are built. Our older receivers used physical 
coils and capacitors in the IF, while these newer ones simulate those Ls 
and Cs in DSP; 2) the system architecture that Wayne developed (for 
example, his choice of IF frequencies, his methods of reducing phase 
noise, keying transients, etc.; and 3) they're a lot better radios that 
most of those older ones.

A ham who doesn't participate in major contests is unlikely to need 
anything more than the 2.7 or 2.8 kHz roofing filter.

73, Jim K9YC