Re: VLF: New EbNaut announcement...

[Markus Vester <markusvester@aol.com>]

Hi Stefan,

your message was decoded well from DL0AO cardioid data.

Initially, the best decode appeared with a phase slope, -30 0 0 30. Entering a frequency offset of one FFT bin (+9.3 uHz), the blue peak seems to be shifted slightly to the left as expected, but the same best decode was achieved with flat phase.

This seems to confirm your earlier observation of a one bin offset. This is strange, as I've never observed such an offset in earlier experiments based on shorter data with wider FFT resolution (31 uHz or more), and I am lacking an explanation. I don't think we can blame propagation because if there was any Doppler around sunset this should be negative rather than positive. 

Best 73,
Markus (DF6NM)

-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mo, 5. Jun 2017 14:44
Betreff: VLF: New EbNaut announcement...

Hi VLF,

For some local tests i like to transmit the 2 character message that i already sent on 970 Hz 3 weeks ago. This time on 6470 Hz....

Such a short message with sch long symbols may be interesting for newcomers or various tests by the established VLF receivers...


f = 6470.100000 Hz
Start time: 05.Jun.2017   13:00:00 UTC
Symbol period: 60 s
Characters: 2
CRC bits: 3
Coding 16K21A
Duration: 9h, 20min
Antenna current: ~ 460 mA

73, Stefan

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