[Elecraft] K2 and FSK

[Leigh L Klotz, Jr.]

I wrote a Linux program for the PSKMeter, and AA6E re-wrote it with a 
nice GUI, and I now use his.  KF6VSG's site has some presentations on 
what the firmware does, and what the PC software does, and I used those 
and some email exchanges with George to write the Linux version.

The firmware does a number of voltage samples of its ADC which is across 
the RF line, and returns the raw values.  The envelope values are all 
positive, so you look for a max, assume the min is the correct number of 
samples away and barrel-shift the data around and then look at that 1/4 
wave to see if it seems to have the right cosine shape, as determined by 
a Fourier decomposition into the first 10 or so harmonics.  (There is no 
need for an FFT because it is really just a single unit of data.)

I heard that the firmware now does PSK63, and I suppose it just samples 
twice as fast.

So, you can do anything that you can do with a very small nmber of 
envelope samples, all rectified to be positive.

Leigh / WA5ZNU

On Tue, 27 Sep 2005 1:14 pm, Sverre Holm wrote:
> -----Original Message-----
> that's the PSKMeter .. I have one but I don't remember who I bought it 
> from
> :)
>
> ... Google sez http://www.ssiserver.com/info/pskmeter/
> --------------------------
> Yes, that's the one, I got several responses, the first after 12 
> minutes!
>
> For $39.35 the audio level is adjusted automatically as bands are 
> changed.
> But only for PSK31, not for FSK as far as I can tell, but maybe with 
> some
> other PC software it would work even for FSK?
>
>
>
> 73
>
> Sverre
> LA3ZA
> http://www.qslnet.de/la3za/
>
>
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