[Elecraft] K3 and CW-Skimmer

[Arie Kleingeld PA3A]

Martin,

I use a softrock instead of a LP-PAN but it works on  about the same 
principles I think.
It is used on a K3  with PDSR-IF as software. CW-skimmer is just used 
sometimes, just for the fun of it.

In PDSR-IF all kinds of data are read from the K3 to keep everything in 
place on screen after you have set the IF-offset.
No matter what bandwidth or mode you use, PDSR-IF follows the K3. Nice 
software.

The CWSkimmer works different, I think it only uses the offset you set 
in the CWskimmer options.

For CW operation BWs,  the roofers that are used in my K3 are 2.1k , 400 
and 200.
If I set the CWskimmer on the right freq with the 400Hz roofingfilter, I 
see the signals shift in the display if I change BW enough so that 
another roofing filter kicks in.

When using different roofing filters in the K3, the IF-offset changes a 
bit in the K3, if you switch to another roofing filter, if I understand 
it correctly.. It has been explained in this reflector that this happens 
for a reason. It has to do with the way the roofing filter is placed 
over the signal you are listening to. There are experts that can explain 
what happens exactly. (So some more info is needed please.)

I was not aware of this problem  untill I used CW skimmer and the N1MM 
logger bandmap and saw that I had to keep the 400 roofer in place 
otherwise the spots would be placed on the wrong freq in the bandmap. So 
that's what happened here.

I wonder if others have seen this behaviour and what they did about it.

73
Arie PA3A


Op 23-2-2011 11:01, DM4iM schreef:
> Elecrafters,
> i know this is not the right place - and off topic- , but i hope for a
> quick solution to the problem without the need to subscribe to yet
> another forum.
>
> Problem:
> I set up CW-Skimmer / LPPan / K3 .
> When i click on a signal i see on the waterfall, the K3 jumps to that
> frequency. In some cases i then hear and see the signal exactly where i
> expected it, in other cases the signal shows up in a different place on
> the waterfall. I tried to compensate for that offset per the manual ,
> but i just don't understand the mechanism behind it. The manual says
> 24000 ( might be 2400 as well - i don't have cw-skimmer on _this_ pc )
> is a good starting point, but that seems to be _far_ off.
>
> Any one?
>
>