[Elecraft] Newbie Question K2 CW Operation

[Bill Coleman]

On Feb 4, 2005, at 4:43 AM, frank wrote:

> 1. The lowest cw pitch note is 400hz (which I think most prefer) but
> the info I read in the manual states its best to use a pitch note
> between 500 to 600hz for best results.   Does anyone have an idea
> why that is the case?

The K2 standard is 600 Hz. You can pick a lower note if you want, but 
this will increase the detection of the opposite sideband (beat note) 
at wider bandwidths.

> 2. The manual states that the cw bandwidth can be selected from 200
> to 2000 Hz.   If you were receiving a solid S9 signal, when you tune
> through the signal is it possible to hear the other side of zero
> beat at any filter bandwidth?

I don't know about all the bandwidths. Note that for bandwidths much 
greater than about 1 kHz, the shape of the CW filter is very 
asymmetric, with an odd hump on one side. For this reason, I have my 
FL1 bandwidth on CW to be 1 kHz.

At this bandwidth and 600 Hz frequency, the opposite sideband is not 
audible with an S9 signal. (very faintly with an S9 +40 signal -- but 
these are rare with the K2's scotch S-meter) It isn't audible at all on 
bandwidths narrower than 700 Hz, nor is it audible with the OP1 filter 
(the SSB option).

> 3. If the DSP option is added does the audio DSP filter track the CW
> bandwidth selection.  Or do you need to select them separately?

Unfortunately, you need to select them separately. It would be nice if 
they tracked.

In general, I find that the CW crystal filter is sharp enough that I 
never use the audio DSP filter. On SSB, however, the DSP filter does a 
nice job of cleaning up the shape of the crystal lattice filter.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901