[Elecraft] DSP & XTAL filter settings?

[w6jd at comcast.net]

My preference is to use the 700 Hz xtal filter and then narrow down the bandwidth with the DSP filters when necessary.

Doug, W6JD
K2/100 #1626

-------------- Original message -------------- 
From: "Solosko, Robert B (Bob)" <solosko at lucent.com> 

> 
> Hello All, 
> 
> I just added the DSP processor to my K2 and adjusted both the DSP and 
> XTAL filters to the same center frequency using Spectrogram. The DSP and XTAL 
> filters work fine together, except that when using the default filter settings, 
> the DSP and XTAL filters essentially duplicate each other and it's not obvious 
> what the best combination of filter settings should be and how the XTAL and DSP 
> filters should be used in combination, particularly for SSB. 
> 
> I found a posting from Tom Hammond from January in which he recommends 
> that for CW, because of the signal loss of the XTAL filters below 200Hz, use the 
> DSP filters below 200 Hz. and the XTAL filters above 200 Hz. Thus, it seems that 
> I should set the CW DSP filters to something like 200 Hz, 100 Hz, 50 Hz and 
> LOPASS, and the XTAL CW filters to something like 1.5 kHz, 1.0 kHz, 700 Hz and 
> 400 Hz. Then, when I want the wider bandwidth, I'd use one of the XTAL filters 
> with the DSP filter set to LOPASS, and when I want the narrower bandwidth, I'd 
> use one of the DSP filters (and since the XTAL filters all would have wider 
> bandwidths, it wouldn't make any difference which XTAL filter is selected). 
> 
> That seems like a reasonable approach to the DSP and XTAL filter 
> settings and combinations on CW. (Comments?) 
> 
> However, I have no idea how to set up the DSP and XTAL filters and what 
> filter combinations to use for SSB. It seems to be a waste of the K2 
> capabilities just to have the DSP and XTAL SSB filters essentially duplicate 
> each other, as their default settings seem to do. So, is there some optimum way 
> to setup the DSP and XTAL filters and use them in combination for SSB that makes 
> best use of the K2 capabilities? 
> 
> Thanks for any advice and suggestions that you can give me. 
> 
> 
> Bob Solosko 
> W1SRB 
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