[Lowfer] Ultra accurate soundcard calibration

[Laurence KL1 X]

Morning All - 

I use the SR cal for 8970 reception already but never used it for Sig tone generation - My challenge is finding an MSK and VLF station that stays on all the time :-)  NPM Hawaii is a straight sea path from here and is a huge signal save for the dusk/dawn phase changes.

 I chanced my arm and switched to Alpha F3's at 14.8K using the Goertzel filters and it too locked this morning - it tends have to have the edge of Alpha F1's and 2's here by a few dBs

 I wanted to check whether the selection of station made a lot of difference as my nearest VLF station is in Washington state a few thousand Kms from here.  At the moment the path to  NAA and NML is is daylight and switching between them the cal stayed very close ie I couldn't discern any change given that they are both some 30dB above noise here this morning - Im wondering whether nightwobble and this geomag/solar stuff changes a lot...I need to read more!

Good stuff - thanks Jay -

Laurence KL 1 X 



> Date: Sun, 3 Mar 2013 12:51:09 -0500
> From: kb4oer at gmail.com
> To: lowfer at mailman.qth.net
> Subject: Re: [Lowfer] Ultra accurate soundcard calibration
> 
> Nice write up. May need to bring my spare computer back upstairs.
> 
> 73, Doug KB4OER
> 
> On Sun, Mar 3, 2013 at 11:40 AM, <jrusgrove at comcast.net> wrote:
> 
> > Ultra accurate sound card calibration using a 'spare' computer and
> > Spectrum Laboratory.
> >
> > http://www.w1vd.com/**SoundcardCalibration.html<http://www.w1vd.com/SoundcardCalibration.html>.
> >
> > Jay W1VD  WD2XNS  WE2XGR/2
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