[Elecraft] K2- setting the filters

[Brian Lloyd]

On May 2, 2008, at 2:12 PM, Jack wrote:

> Q4, The filter widths are actually much wider than that set on the  
> K2 display. ie 2KHz filter is actually about 3KHz wide. To get the  
> same "sound" as my other HF rigs I am having to set the filter  
> widths much narrower than expected. ie set the display to 1.2KHz  
> width to get an actual 1.8KHz width trace on spectrogram. Is this  
> normal? Can this be adjusted? Am I worrying about nothing? :o)

Interesting. On our K2 the reported filter width was narrower than  
reported by the K2. I set the 3dB points using an audio spectrum  
analyzer and found that using a setting of almost 1KHz to get a 500Hz- 
wide filter. No problem changing widths to anything I want but it  
seems that the reported widths and actual widths vary widely. The only  
way to know for sure is to sweep the filter or dump in noise and  
analyze with the audio spec-A.

BTW, for people using Macs, you can do the same filter setup using  
CocoaModem's spec-A display.

> Overall i am very happy with the recievers performance. The K2 has  
> taken over as main radio, pushing japanese sets aside.

Same here. The IC-706 has been removed from the shack at school and  
has been replaced by the K2 and a cheap 2M mobile FM rig.

>
> But if anyone could advise on the above, that would aid my learing  
> process. Thats one of the reasons why i bought it :o)

I would really like to hear why the actual filter width varies so  
widely from what the radio reports too.

Brian Lloyd
Granite Bay Montessori School          9330 Sierra College Bl
brian AT gbmontessori DOT com          Roseville, CA 95661
+1.916.367.2131 (voice)                +1.791.912.8170 (fax)

PGP key ID:          12095C52A32A1B6C
PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C