[Elecraft] K2, Rigblaster&Timewave 599zx

[Don Wilhelm]

Michael,

Responding to your query about the filters - let me see if I can help a bit.

First, the bandwidth of the filter can be adjusted - set the filter
bandwidth first.
Then - after setting the filter bandwidth, you adjust the BFO frequency to
produce the tone that you prefer to hear.

When adjusting the BFO, one can change the resultant audio tone so that it
matches your chosen sidetone frequency.  One caution though - make certain
that you have the BFO frequency set to the correct side of the filter center
frequency (low numbers for LSB/CW-Norm and higher numbers for USB/CW-REV
otherwise there will be no difference between CW and CW-R or between LSB and
USB).

Although you can use a single signal as input ot the receiver while
adjusting the BFO frequencies it can be misleadding because it is difficult
to determine that the input signal is really centered at the peak of the
filter passband.  It is much easier to use a wideband noise source.  The
noise on a 'dead band' can be used in place of a wideband noise generator
but is not quite as reliable as the controlled noise generator.

If you are not using Spectrgram (or similar analyzer) - adjust the BFO
frequency so that the loudest recovered audio frequency is the same as your
selected sidetone frequency.

If you are using Spectogram to give you a visual picture of the response
things get a lot easier - set a marker at the audio frequency of your
selected sidetone, then adjust the BFO frequency so that the displayed
passband is centered on that sidetone frequency.  You can set the BFO
frequencies 'by ear', but Spectogram and its visual display of the recovered
audio makes the ask a LOT easier.

73,
Don W3FPR

----- Original Message -----

> I finally have the k2 all done except for the PA which I have but won't
> start until I have the K2 all set up.  I'm still playing around with the
> filters.  I'm confused about setting the digital filters.  Actually, all
the
> filters confuse me.  Something hasn't clicked in my mind yet.  I'm using
> spectrogram but I'm not sure what I'm looking at.  I get it after a while,
I
> hope-hi.