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Re: VLF: DK7FC > W1VD 8.27 kHz EbN0 success!

To: [email protected]
Subject: Re: VLF: DK7FC > W1VD 8.27 kHz EbN0 success!
From: DK7FC <[email protected]>
Date: Mon, 19 Feb 2018 18:15:57 +0100
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Hi Markus,

Thanks. Yes you are right, almost to good to be real. But there was no fine tuning necessary, no frequency offset, no unexpected timing offset, no additional false messages. It seems to be true :-)
The best SNR was 10.5 dB in 39.1 uHz. Unbelivable!
Based on that, the 2 char message should be there after 2 nights, easily: http://abelian.org/ebnaut/calc.php?sndb=10.5&snbws=0.000039&snmps=&code=16K21&sp=30&crc=22&nc=2&submit=Calculate
Maybe even after one night?

Tomorrow will be interesting...

73, Stefan

Am 19.02.2018 18:05, schrieb Markus Vester:
Wow that's almost too good to be true! The "holy grail" of E-W transatlantic, achieved in a single good night. Congratulations to Jay and Stefan, for boldly daring this experiment and bringing it to this surprising success! 

Best 73,
Markus (DF6NM)

-----Ursprüngliche Mitteilung-----
Von: DK7FC <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Mo, 19. Feb 2018 16:00
Betreff: Re: VLF: DK7FC > W1VD 8.27 kHz EbN0 success!

Hi Jay, VLF,

An excellent achievement below 9 kHz! And even from a single night, without stacking!!! I expected we will need about a week, or even more.

To leave a carrier trace or even a message decode over that path, from east to west, was one of the goals during the kite experiments in 2010/2011, where my ERP was 20 dB higher. We mever managed that. Until now!

So maybe the E>W path is less than 20 dB harder. That opens the door for more imaginations about VLF DX, not only for me.

We need to proove that this is reproducable :-) So let me try a 2 character message starting this night:

f = 8270.1000 Hz
Start time: 19.FEB.2018  22:3:00 UTC (daily)
Symbol period: 30 s
Characters: 2
CRC bits: 22
Coding 16K21A
Duration: 07:12 [hh:mm]
Antenna current: 700 mA


In the attachment one can see the results put out by the Linux decoder running on the file you sent me this morning. Only right decodes and improving rank.

Can we really expect 2 characters in 2 days? We will see! Let's go!

73, Stefan




Am 19.02.2018 15:41, schrieb [email protected]:
Stefan's transmission:
 
f = 8270.1000 Hz
Start time: 12.FEB.2018  22:32:00 UTC (daily)
Symbol period: 32 s
Characters: 1
CRC bits: 24
Coding 16K21A
Duration: 07:06:40 [hh:mm:ss]
Antenna current: 700 mA

After a week of trying ... including two nights with TX problems, one night with RX problems and one night with high noise levels ... a successful decode of Stefan's message was made on last night's transmission. s/n in 39 uHz 10.5 dB and Eb/N0 2.54 dB. It was pretty convincing as the decode popped up in the 0,0,0,0 phase trial and only improved thereafter.
 
Congrats Stefan on what appears to be the first E>W T/A on Dreamers Band!
 
Jay W1VD 
 
 
    

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