On May 9, 2006, at 9:30 AM, Solosko, Robert B (Bob) wrote:
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).
One thing I would like in the K2 is a firmware change that would
invoke a given XTAL and DSP filter combination. Certain DSP filter
settings may not make sense when combined with other XTAL filters.
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.
On SSB, there's basically one XTAL filter - OP1. The variable
bandwidth filter is pretty asymmetric for use on SSB. OP1 also has a
very modest shape factor.
I use the DSP filter to clean up the shape of the OP1 filter. I have
a couple of variants programmed that cut the high and low end of the
filter. These are useful during contests or any time there's lots of
QRM. Narrowing the filter may slightly reduce intelligibility, but it
also cuts adjacent signals.
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?
I have my DSP set up for LPASS, 200-2400, 300-2200, 300-2000 (I
think). My K2 is a bit unusual as I have the "1.9" kHz SSB filter, as
designed by KI6WX. This is similar to the original K2 SSB filter -
about 2.0 kHz wide, but the caps have been modified to give a
bandpass with less ripple.
Oh, and I leave the automatic notch filter on in SSB all the time.
Bill Coleman, AA4LR, PP-ASEL Mail: [EMAIL PROTECTED]
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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