Re: VLF: First VLF detection DL > EA

[Markus Vester <markusvester@aol.com>]

Nice decode again in Nuremberg (attached). At DL0AO and DF6NM, I'm using the SpecLab IIR Bessel bandpass filter before the noise blanker. The filter bandwidth has been reduced to 600 Hz (nominal), providing sufficient attenuation of the neighboring military MSK stations. The noiseblanker uses 8 dB threshold and 3 ms ramp time.

Stefan, would it be possible to leave the carrier on during a full day (sunrise to sunset)? I'd be interested to obtain a phase diurnal also for the Heidelberg to Nuremberg path.

73, Markus



-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mi, 6. Dez 2017 14:22
Betreff: Re: VLF: First VLF detection DL > EA

Hello Luis,

Congrats to you and us :-) First VLF message DL to EA. On your grabber i saw that JXN is much stronger at night and your QRMing neighbours seem to sleep. We could try a longer message at night. Maybe 3 characters, to be conservative.
It looks like starting at 22 UTC (due to the neighbours) and stopping at 06:30 UTC is a good choice. So we have a time window of 8.5 hours. For example:

f = 17470.1000 Hz
Start time: 06.Dec.2017  22:00:00 UTC
Symbol period: 40 s
Characters: 3
CRC bits: 10
Coding 16K21A
Duration: 08:32 [hh:mm]
Antenna current: 1 A

I will try that tonite, except you can decode the 4 char message that i sent last night :-)

73, Stefan

...

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