Re: LF: New EbNaut tx: R7NT

[Domenico IZ7SLZ <iz7slz.domenico@gmail.com>]

Hello Alex, LF

i made  further investigations at recording files related to your EbNaut transmissions of yesterday. Using DF6NM's application SHOWRAWSYMS.EXE (thanks Markus!), i have found some better offsets and decoded your message as follow:

QTC: 73!R7NT

UTC      Eb/N0[dB]   Eb/N0 carr[dB]   time off [s]    freq. off [Hz]

15.30    -----      10.1               -484.59        41.9944
16.00     4.1      6.3                 715.59         41.996
16.30     7.7      13.4               715.59          41.994
17.00     5.0       12.0              715.59          41.9944
17.30     4.4        7.5               715.6           41.9928
18.00     4.6        8.2               715.6           41.9928
18.30     1.7        3.7               715.58         41.9929
19.00     3.2        6.8               715.58         41.9929

Again congratulation for your first EbNaut transmission and ad maiora !

73, Domenico iz7slz

On 18 December 2016 at 21:36, Domenico IZ7SLZ <iz7slz.domenico@gmail.com> wrote:

Hello LF, EbNauters

my rx setup was not ready to pick-up earlyer R7NT's  transmissions.

The first usable file starts at 15:38 UT. I used this file to catch the 15:30 transmission (-484.6 s) and i got the decode !

First EbNaut R -> I . Thank you Alex !

Of course Eb/N0 is invalid due to plenty symbols missed.

I tryed to decode following transmissions without results (yet). It is hard becouse of frequency drift due to transmitter and propagation. Maybe a shorter message (less characters) can help.

Alex, can you tell us witch setup are you using ?

In the folder http://qsl.net/i/iz7slz//R7NT/ i have uploaded some .wav files, maybe someone is more lucky and skilled  then me in catching !

73 to all,

Domenico iz7slz

On 18 December 2016 at 19:41, Markus Vester <markusvester@aol.com> wrote:

No I believe it's the transmitter itself, probably temperature drift of a crystal oscillator. We also find a similar frequency variation in R7NT's opds spots. For EbNaut, 5 milliHz is quite a lot. 

73, Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 18 Dez 2016 7:25 pm
Betreff: Re: LF: New EbNaut tx: R7NT

Hello Markus,

Such a small drift, could it be propagation? It was during the onset of the night.

I played a bit further and changed the frequency offset from 41.993 Hz to 41.9931 Hz and got a 0.8 dB better Eb/N0.

73, Stefan

Am 18.12.2016 18:42, schrieb Markus Vester:

Got a valid decode here as well. The signal is quite strong, but drifted by about 5 milliHz.

Best 73,
Markus



-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 18 Dez 2016 6:18 pm
Betreff: Re: WG: LF: New EbNaut tx: R7NT

Hi Alex, LF,

Also copied R7NT here in Heidelberg. An early decode. First decode from Russia here.
There is an offset of -7 mHz. First i tried 42 Hz offset (offset to 137.5 kHz) and got no decode. It shows how critical the timing is. But it also shows how helpful Markus' 'show_rawsyms3b' feature is.

73, Stefan

Von: Alex K
Gesendet: Sonntag, 18. Dezember 2016 12:47
An: rsgb_lf_group; rsgb_lf_group
Cc: Markus Vester
Betreff: New EbNaut tx: R7NT

 

Hello LF!
R7NT is now txing EbNaut
--------------------------
Freq:   137542.00
Code:   8K19A
Symbol:   2.0 s
Len:   8
Time:   1312.0 s (21m 52.0s)
Every hh:00 and hh:30 min
----------------------------


--
Alex RN3AUS