Re: LF: 2200M EbNaut Beacon

[Markus Vester <markusvester@aol.com>]

Hi Rob,

here's the result for 41 files recorded in Nuernberg during the last three nights. By correlation to the known message, the Eb/N0 was estimated for each transmission until our sunrise. As expected, best SNR occurred around 3 UT, and the median Eb/N0 of all 41 transmissions was -6.6 dB.

The best three files were then fed to the decoder, producing two decodes after 2:30 (+1.0 dB) and 3 UT (-0.2 dB) last night Oct 1st. The third-best file (Sep 30 2:30, -1.0 dB) failed to decode. Thus putting the threshold at -0.6 dB between the second and the third, we find that for 50 % success rate on our path you would either need to increase power by 6 dB, or reduce the number of characters by a factor of 4.

Note that the Eb/N0 output from the decoder was a couple of dB higher than from correlation, for example 3.2 dB instead of 1.0 dB, but the threshold calculations should still be valid.

Best 73,
Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: Rob Renoud <k3rwr@md.metrocast.net>
An: RSGG_LF <rsgb_lf_group@blacksheep.org>
Verschickt: Fr, 28. Sept 2018 15:49
Betreff: LF: 2200M EbNaut Beacon

Hello 2200 Meters EbNaut,

I will run the EbNaut beacon on 28, 29 and 30 September from 2300 UTC to 1100 UTC this coming weekend as follows:

Code: 8K19A
Symbol Period: 1.5 sec
CRC: 16
Number of Char: 15 (K3RWR_FM18QI_73)
Signal Bits: 992
Duration: 1488 sec (00:24:48.00)
Frequency: 137470.000 Hz
TX Sequence: 2 X per hour starting on minutes 00 and 30
Power: 1 Watt EIRP

Reports and comments welcome :-)

73,
Rob - K3RWR
FM18qi
“Practicing the Art of Radio”

10010248_result.png
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10010248_sym.png
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EbN0_vs_time.png
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EbN0_statistics.png
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results_k3rwr_df6nm_15char.txt
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