Re: VLF: EbNaut also on 8270.033333 Hz

[DL4YHF <dl4yhf@freenet.de>]

Hello Markus and all,

Am 18.02.2017 um 18:19 schrieb Markus Vester:

Thanks Wolf, there's indeed a beautiful Whistler festival going on! After having read the post on the VLF Group, I had listened in Thursday night which was already quite extraordinary, But right now the activity is even more intense! And your vlf6 stream seems to be in a prime position. Are you feeding it from your wireless E-field antenna?

Yes, it's still the low-power purely analog FM-linked antenna rod on top of the remaining part of a Rowan tree,
shown near the end of the old VLF page at http://www.qsl.net/dl4yhf/vlf_reception/VLF_Receivers.html .

Nice replacement for 'ambient music', only the occasional QRM which sounds like a washing machine disturbs it. Maybe the rabbits living in the basement of our club station are running electronic gadgets... they are the only inhabitants there at the moment :-)

73,
  Wolf .

Well, how much power would be needed for a narrowband Amateur signal to be detected in Madagascar, what is the path loss? Think I've read somewhere that whistler propagation could possibly even be enhanced by stimulated emission, providing Maser-like amplification rather than attenuation.

Thanks again to the contributors of these beautiful natural radio streams!

All the best,
Markus (DF6NM)
 


-----Ursprüngliche Mitteilung-----
Von: DL4YHF <dl4yhf@freenet.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 18. Feb 2017 15:25
Betreff: Re: VLF: EbNaut also on 8270.033333 Hz

Hi VLFers,

Turn up the power, you may trigger a Whistler ... well, no, joking aside: At the moment there's an impressive whistler storm happening. Fascinating listening to Paul's internet VLF audio streams ( http://abelian.org/vlf/ ).

73,
  Wolf DL4YHF .

Am 18.02.2017 um 14:41 schrieb Markus Vester:

Hi Jacek, VLF,

from previous successful DK7FC decodes, it looks as if you might also be able to receive a ~10 dB weaker signal from here (10 uW EMRP). Apparently the rain has ended now, so I would like to try an overnight EbNaut transmission with only two characters:

Frequency: 8270.0333333 Hz,
2 characters, 8K19A, 18 bit CRC (!),
90 s symbols, message duration 9:36 hours,
start 2017-02-18 19:00 UT, end 4:36 UT (Sunday) 

The 1/30 Hz frequency offset has been chosen to avoid mutual interference with the announced DK7FC transmission on 8270.1 Hz: With the frequency spacing being an integer multiple of both symbolrates, and synchroneous bit timing, the symbol waveforms should be orthogonal because the "other" signal always undergoes a whole number of 360° cycles during the decoder's symbol integration interval.

Best 73,
Markus (DF6NM)
    


-----Ursprüngliche Mitteilung-----
Von: Jacek Lipkowski <sq5bpf@lipkowski.org>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 14. Feb 2017 17:23
Betreff: Re: LF: Re: DK7FC EbNaut message on 8270.1 Hz decoded nr Moscow by RN3AUS

Nice decode here for your transmission on 13 Fen 2017 20:40

found rank 0 ber 3.0469e-01 Eb/N0 10.7 M -1.697070885e+01 [XX] ps [ 0 0 0 0 0]
carrier phase: 5.3
carrier Eb/N0: 10.9
carrier S/N: 21.44 dB in 32.6 uHz
elapsed 29

Switched the message to XX (sent to Stefan off list), so i don't spoil
other's fun

VY 73

Jacek / SQ5BPF