Re: Re: VLF: Uwe Opera-4H

[uwe-jannsen@kabelmail.de]

HI Peter,

I changed the TX QRG to 8912.5Hz running SpecLab in Op-4H (ASK0) mode and made a first test with positive result.

the RX was located in 3km distance - Opera v.1.5.0 , RX aerial a 10m wire connected to the soundcard.   

TX output pwr about 1W.  pse see:

http://dj8wx-dl.de/opera3.jpg

I think we should have a try as you are my nearest station rxing VLF.

Now Im increasing the PA output pwr to 500Wrms.

GL

Uwe/dj8wx  

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Von: rsgb_lf_group@blacksheep.org
Gesendet: 29.12.2013 09:45
An: rsgb_lf_group@blacksheep.org
Betreff: Re: VLF: Uwe Opera-4H

---

Hello Uwe, Markus, VLF

 

Nothing was seen or detected here from your transmission in OPERA mode either.

No recognizable trace at all.

While you're continuous unmodulated signal almost overloads my soundcard input.

 

73's Peter - PA1SDB

 

 

 

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

From: uwe-jannsen@kabelmail.de

To: rsgb_lf_group@blacksheep.org

Sent: Saturday, December 28, 2013 9:08 PM

Subject: Re: VLF: Uwe Opera-4H

yes Markus, I have had the screen showing the SecLab components in my focus whilst doing  other jobs - for hours.

Now the carrier only mode is on the air.

Until next test

GL

Uwe/dj8wx

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Von: rsgb_lf_group@blacksheep.org
Gesendet: 28.12.2013 19:07
An: rsgb_lf_group@blacksheep.org
Betreff: VLF: Uwe Opera-4H

---

Uwe,

 

sorry, nothing was seen or detected here from your transmission today. Not a trace. Der erste Versuch ist meist nicht genuch (Didi Drahtlos). 

 

Yes I noticed the good trace on Paul Nicholson's spectrogram http://abelian.org/vlf/fbins.shtml#p=1388246400&b=080&s=sp. Just look at it the other way round: You did send a long carrier, only with some short interruptions. But the gaps were so short that the spectrum didn't notice them ;-) 

 

More seriously: Compared to a continuous carrier, with 50% duty cycle the carrier component is still there but 6 db down (half average voltage). In terms of power, on average you are spending 50% of the power. 25% (-6 dB) goes to the central carrier, and the other 25% into the AM sidebands carrying the message.    

 

What I find strange is that the spectrogram trace seems to have jumped 28 mHz low, once near the beginning and again for an hour around 14:30. Are you sure that your samplerate correction had been engaged without interruption?

 

Best 73,

Markus (DF6NM)

 

From: uwe-jannsen@kabelmail.de

Sent: Saturday, December 28, 2013 3:05 PM

To: rsgb_lf_group@blacksheep.org

Subject: Re: Re: LF: Sending Opera with SpecLab

OK., Markus, but the Todmorden grabber shows the signs.its a surprise for me. I didnt expect it samples such relative short signs.
GL
Uwe/dj8wx
tks for the correction.

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Von: rsgb_lf_group@blacksheep.org
Gesendet: 28.12.2013 12:47
An: rsgb_lf_group@blacksheep.org
Betreff: Re: LF: Sending Opera with SpecLab

---

Uwe,

 

good news! I'm watching and searching ;-) 

 

Background noise seems to be a few dB higher than the last couple of days, but we'll see what's possible anyway. Unfortunately the OK2BVG grabber website appears to be down at the moment.

 

Good luck!

 

73, Markus (DF6NM)

 

PS: In my original mail, the Op-8 line in the speed table erroneously contained an entry for Op-4. This has been corrected beneath.  

 

From: uwe-jannsen@kabelmail.de

Sent: Saturday, December 28, 2013 12:14 PM

To: rsgb_lf_group@blacksheep.org

Subject: LF: Sending Opera with SpecLab

Hi all,
the PA has been switched on. the next txt block will start now.
GL
Uwe/dj8wx

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Von: rsgb_lf_group@blacksheep.org
Gesendet: 27.12.2013 15:47
An: rsgb_lf_group@blacksheep.org
Betreff: Re: Re: LF: Sending Opera with SpecLab

---

Hi Markus, Wolf, Stefan, Peter es all,

tks for the advice, Markus

now SpecLab is beaconing in mode Op-4H on 8969.99Hz

the PA is off until it is dry outside.

I keep your proposal  txing btwn 0700 and 1400MEZ in mind, Markus.

GL

Uwe/dj8wx/dj8CAT