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From: "Thomas Martin" <df7tv@arrl.net>
To: elecraft@mailman.qth.net
Date: Sun, 12 Jan 2003 17:13:09 +0100
Subject: Re: [Elecraft] K2 S/N 3105 on the air -- crystal filter curves

Hello Tom,
thank you very much for your expert's view to my
recordings.

Yes -- concerning the signal level to the soundcard I think you are right, 
that it may be to high.

Beside your recommendations concerning the settings within Spectrogram on 
High Band Limit and Scale I'll also try the 200Hz filter and introduction 
of an attenuator within the audio line from the K2 to the soundcard. In 
fact I had to reduce AF and RF gain to a very low level when doing the 
recordings even after switching the PREAMP OFF.

Again thanks for your time and all the valuable information you provide to 
the list.

73
Thomas, DF7TV


Datum:          Sun, 12 Jan 2003 09:16:26 -0600
An:                     "Thomas Martin" <df7tv@arrl.net>
Von:                    Tom Hammond NØSS <n0ss@earthlink.net>
Betreff:                Re: [Elecraft] K2 S/N 3105 on the air -- crystal filter 
curves
> 
> The Spectrogram displays look quite good, but a bit 'wider' than nromal. It 
> appears that you may have been applying more signal to your sound card than 
> is required.
> 
> I would suggest that you re-run your displays (not necessarily re-run the 
> alignment, but just the record of the displayed data) with your Spectrogram 
> "SCALE" value set to "60dB" instead of "90dB), your Spectrogram High Band 
> Limit set to no more than "3000", and your AF Gain set to provide about 
> 30dB of signal level on the display.
> 
> At the input level which you used for recording the displays, I believe 
> that it makes it appear as though the bandwidths are a bit wider than 
> normal. I think that at a lower drive level they will appear a bit more 
> 'normal'.
> 
> It does appear that you have the filters nicely 'centered' over the 
> sidetone marker, however reducing the Spectrogram High Band Limit will give 
> you a better range of frequencies for more accurately centering the 
> passband over the sidetine marker.
> 
> I think you will find that your actual settings for the BFO will probably 
> be very close or even exactly where they should be, but that the displays 
> may be a bit better.
> 
> Well done,
> 
> 73,
> 
> Tom Hammond   N0SS

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