Re: LF: EbNaut decodes last night

[Markus Vester <markusvester@aol.com>]

Hi Joe,

very nice results from your SpecLab files!

I easily saw my carriers and the PSK symbols in each of the files, so there was no need to make use of the pilot. Then in 6 out of 7 files, I decoded the *OBELIX* message, and tweaked each time offset for best SNR. Knowing my transmit start time (0.2 s after the hour), I could then derive that your PC clock had been 2.1 to 2.6 seconds late. Note that this would have been impossible if the signal hadn't shown up the rawsyms plot, which is why we usually  depend on reliable timing.

Using the time and frequency information, I calculated theoretical offsets for the IW4DXW. who was transmitting 4.9994 Hz below me. Unfortunately Ric's signal wasn't quite strong enough to produce a plausible decode (perhaps due to the snow on his antenna).

EbNaut received by VO1NA on 2016 Dec 30:

VO1NA  --------DF6NM----------    ---VO1NA---  --------IW4DXW-----------
file   foffs  start  sym  carr     rx  clock     foffs    start  decode
hhmm    Hz     s      dB   dB      Hz    s         s        s

0122 -9.8955v 306.9     nil      drift  -2.1
0212 -9.8984  306.9   5.5  6.2   .1016  -2.1   -14.8978  306.7  nil, qrm
0312 -9.902   306.8  11.9 14.0   .098   -2.2   -14.9014  306.6    nil   
0412 -9.9032  306.8  11.0 12.1   .0968  -2.2   -14.9026  306.6    nil
0512 -9.9043  306.6   3.7* 7.7   .0957* -2.4   -14.9037  306.4    nil   *glitch?
0612 -9.9048  306.4  10.4 11.5   .0952  -2.6   -14.9042  306.2    nil
0712 -9.9053  306.4   8.5  9.0   .0947  -2.6   -14.9047  306.2    nil

I'd like to try a 13 character message tonight:

 137490 Hz,
 13 char, 2 s, 8k19a,
 starting each hour since 0 UT + 0.2 s,
 5 min carrier before and after.

All the best,
Markus (DF6NM)


-----Ursprüngliche Mitteilung-----
Von: markusvester <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Fr, 30 Dez 2016 2:39 pm
Betreff: AW: LF: EbNaut decodes last night

Hi Joe,

 

the ones centered 12 minutes past the hour, ie. filenames 1230xx12.txt, please.

 

73, Markus

 

Von: jcraig@mun.ca
Gesendet: Freitag, 30. Dezember 2016 14:19
An: rsgb_lf_group@blacksheep.org
Betreff: Re: LF: EbNaut decodes last night

 

Hi Markus,

 

Files 12300102, 112 122 133.txt etc are on disc.

Which ones would you like to have uploaded?

 

73

Joe

 

 

 

12300312_sym.png
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12300312_result.png
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