Re: Re: Re: VLF: Transmit phase correction

["Markus Vester" <markusvester@aol.com>]

Uwe,

 

great to see that it works so well.

 

Regarding soundcard input levels, I actually had the opposite problem: On my internal soundcard ("Conexant High Definition SmartAudio HD2", probably too smart for me ;-), the stereo mic input was much too sensitive for direct connection of the 5 V pulse from the Jupiter GPS unit. It worked fine after setting the mic volume slider to minimum (0%), and inserting 68 k and 10 k resistors in series with the right (GPS) and left (analog loopback) inputs.

 

Best 73,

Markus (DF6NM)

 

 

----- Original Message -----

From: uwe-jannsen@kabelmail.de

To: rsgb_lf_group@blacksheep.org

Sent: Friday, January 24, 2014 1:14 PM

Subject: Re: Re: Re: VLF: Transmit phase correction

Yes, Markus, my TX  has been ZOA with SpecLab set to phase correction.
all grabbers show a vy clean line never seen before. Thanks for that .USR file.

But…..

I had problems finding a proper soundcard. At last a new sound blaster audigi made it. But not 100%.
To get the 1PPS peaks ok, the record amplifier must be set to 100% and no NMEA signs to receive.

with  SpecLab settings not using the phase correction the soundcard recorder must be set to abt 2% to get the 1PPS peaks and NMEA ok.

With other soundcards – like an vy old Sound Blaster, Musen and Generic  - the 1PPS and the NMEA signs where ok when the record slider was set to 100%. But obviously no phase correction occurred. Rainbow colours in the trace.

Ok, it is all fine now, the trace gleams in lime green, i.e. 180° locked.

GL

Uwe/dj8wx

 

---

Von: rsgb_lf_group@blacksheep.org
Gesendet: 24.01.2014 10:30
An: rsgb_lf_group@blacksheep.org
Betreff: Re: Re: VLF: Transmit phase correction

---

Hi Uwe,

 

wonder if you've been testing the phase correction scheme on air last night? The PA1SDB grabber is now showing a nice narrow peak in 47µHz.

 

I have also run an experiment with two local carriers: 8269.998 from anotherPC running SpecLab with phase correction, and 8270.000 from a decadic syntheziser to check my grabber's integrity. Sometime in the wee hours the amplitude of the SpecLab trace jumped up, presumably to increased leakage from a loose shield connection on the audio cable. But both traces seemed to be glitch-free over many hours.

 

Best 73,

Markus (DF6NM)

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