KDSP2 Audio Filters

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KDSP2 Audio Filters

KC9QQ
I recently constructed and installed the KDSP2 in my K2.  I installed it after I had installed and aligned the KSB2 using Spectrogram.  I notice that the KDSP2 seems to work wonderful in CW, but when I am listening to SSB signals the audio sounds as if it is passing through a tin can.

I saw in another post a discussion on adjusting the AF1..AF4 in addition to the FL1..FL4.  Is this done using CAL FIL or must this be done within the KDSP2 menus settings?

I saw the following post on adjusting the KDSP2 audio filters, but the process to use is not obvious to me:

You do it just the way you would without the DSP unit.
First select the pitch you want to have at the center of the filter.
I use about 550 Hz here.
Then adjust the KDSP2 for the narrowest setting you want to use,
say 100 Hz, centered on the pitch you have selected.  Now do
the adjustments to the crystal filter at its narrowest bandwidth
until you see the most even symmetrical passband curve.

Now step the DSP unit to the next wider bandwidth you want, and do
the same for the crystal filter.  Again adjust the crystal filter
for the best looking curve at that bandwidth.  Keep doing this up
to the widest bandwidth of the crystal and DSP filters.  For
convenience I use the same bandwidth in both filters at a given
selection setting--XF1=AF1, XF2=AF2, etc.

Good luck and 73
Bob N6WG
The Little Station with Attitude


Thanks,

Fred, KC9QQ
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Re: KDSP2 Audio Filters

Chuck Teague
Fred,
I would use spectrogram to set the audio filters--it helps me to get a visual of what the pass band will look like, and it's just easier to keep track of what you're doing.  Use the DSP menu settings for the audio filter setup--your xfilters are already set.

Chuck
NN7U
Chuck Teague
NN7U