[Elecraft] K3: 2.1 vs 1.8

[Jim Brown]

On Sat, 12 Jul 2008 06:13:31 -0400, DOUGLAS ZWIEBEL wrote:

>Roofing filters work to help knock out IMD (intermod) which may be
>encountered when multiple, very strong signals (stronger than Mike's
>59+10) populate the band. 

YES!  It's important to remember that the add-in filters are ROOFING 
filters, not IF filters. The K3 does its own IF filters in DSP, and they 
work very well. The add-in filters mostly matter in the really intense 
conditions of contesting and DX chasing, especially when W0YK, K6XX, N6RZ, 
and W6DRX are all very close neighbors. Luckily, three of thm 

An hour or so of SSB time during IARU made me pretty comfortable with my 
choice of the 8-pole 1.8 kHz filter, and also the setting of 2.2 kHz for 
when it kicks in. I do agree with W0YK and others about the IF shift. Still 
some tweaking and listening to be done with shift and bandwidth of the IF 
filters, but I do like the sound of how they cascade, and I do agree with 
those who feel that the 1.8 kHz 8-pole filter is the one to buy for SSB 
contesting. 

73,

Jim Brown K9YC