[Elecraft] 8 pole vs 5 pole..I knew this would happen

Lyle Johnson kk7p at wavecable.com
Fri May 4 01:29:13 EDT 2007


> Yes, that is exactly the point I was trying to make!  You can have it as 
> you like it (I am speculating a bit about the control options in the 
> firmware, of course). Some people like a wider width at the first IF to 
> hear signals approaching, even if it opens the window for AGC blocking 
> or desense. Others would want the two passbands to be exactly aligned 
> and as narrow as possible, which would provide the best IMD and AGC 
> performance, but then the signals will drop off the cliff as you tune. 
> What you appear to have done is allow nuance in these adjustments, which 
> I think is quite clever and well thought out. I can't wait to play with it.

One other feature you're sure to like, then, is the CW "context" or 
"PB2" filter.  Set this one as wide as you like -the crystal filter 
selection will be driven by this.  Then set a "suppression level" maybe 
down 10 or 20 or 30 dB.  Overlay this with the narrow filter you want 
and presto!  You can hear the context from nearby stations, but at 
reduced amplitude, while the signals in the narrow filter you are 
working (or trying to work :-) are emphasized and drive the AGC level.

73,

Lyle KK7P



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