Re: LF: K3RWR LF EbNaut Trial #2

[Markus Vester <markusvester@aol.com>]

Hi Rob,

last night I got valid decodes for every single timeslot between 0 and 4 UT, but none before or after. The decoder always produced the correct result already during one of the initial flat-phase trials, only sometimes the rank improved with later +- 30° variations.

180328-29
start EbN0 rank
 UT    dB
0000  0.4  932
0030  1.4  0
0100  4.4  0
0130  3.6  0
0200  3.0  0
0230  0.3  13
0300  3.3  0
0330  1.7  0
0400  4.0  0

Best 73,
Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: Rob Renoud <k3rwr@md.metrocast.net>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mi, 28. Mrz 2018 19:44
Betreff: Re: LF: K3RWR LF EbNaut Trial #2

Marcus,

TU for the reports.  Very nice signal levels at 0200 and 0400.

Yes, 12 char, CRC 15, 2 s symbols is a viable QSO candidate.

I will begin transmitting overnight a 12 character message for the next three days  as follows:

Coding: 8K19

CRC:  15

Symbol Period: 2 sec

Length:  12 characters

Duration:  28 minutes

Message repeated on the Hour & Half-Hour

Frequency:  137.395 KHz

Start Time:  2200 UTC daily

Stop Time:  1000 UTC daily

Days:  28/29 Mar, 29/30 Mar, 30/31 Mar

Reports and comments welcome :-)

73,

Rob - K3RWR FM18qi

On Mar 28, 2018, at 06:11, Markus Vester <markusvester@aol.com> wrote:

Hi Rob,

three decodes again last night:

 UT   dB
0100  1.0
0200  8.2
0400  5.4

Although the signal is sometimes quite strong, it is undecodable due to fading or phase variation at other times. For a two-way QSO I would probably prefer shorter messages (e.g. 12 char, CRC 15, 2 s symbols, 28 minutes total) which may come through more reliably. They will also decode more quickly, ideally allowing an answer in the next time slot.

Best 73,
Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: Markus Vester <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 27. Mrz 2018 17:06
Betreff: Re: LF: K3RWR LF EbNaut Trial #2

Congratulations Ric and Rob!

On their way to Italy, two of last night's transmissions also stopped by in Nuremberg, 3 UT (3.0 dB) and 4 UT (2.0 dB).

Best 73,
Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: Rob Renoud <k3rwr@md.metrocast.net>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 27. Mrz 2018 14:01
Betreff: Re: LF: K3RWR LF EbNaut Trial #2

Riccardo,

Wow - well done at your QTH!

Transmitting at 1W EIRP here.  Antenna is a 12.4m vertical wire with 140m of top loading.

I will transmit overnight 27/28 March again with the 30 character message repeating every hour.  Will then switch to a 20 character message with 1 second symbol period repeating every half hour.  Will post the details of the new message on this web site.

Thanks & 73,

Rob - K3RWR

On Mar 27, 2018, at 05:00, Riccardo Zoli <riccardozoli80@gmail.com> wrote:

Hi Rob, Markus, Stefan, LF

Congrats for recent LF EbNaut success!

Last night, I have decoded your message here in JN64bw (Ariano). This is a new LF EbNaut W->E QRB record: 7048 km.

UTC 0200, Eb/N0 = 2.2 dB (see attachments).

My rig is a homebrew SDR, clocked by a GPSDO. The antenna is an inverted L 12m height, 36m long.

All the best

73 de Riccardo IW4DXW

2018-03-27 1:29 GMT+02:00 Rob Renoud <k3rwr@md.metrocast.net>:

Stephan,

Thank you for your most insightful, and correct comments.

I will continue to explore EbNaut as a communications and QSO mode on 2200m.  Your suggestion to focus on messages taking up to 25 minutes and containing 15 characters fits well with using EbNaut as a QSO mode.  

I have both Windows and Linux computers - plan on starting with Windows and transition to Linux as I gain confidence with EbNaut RX.

Tnx & 73,

Rob - K3RWR

On Mar 26, 2018, at 15:55, DK7FC <selberdenken@posteo.de> wrote:

Hi Rob,

Am 26.03.2018 19:28, schrieb Rob Renoud:

Very nice - thanks for you detailed reception reports for the hours between 00:00 and 06:00 and, of course, the decode at 03:00.

No problem.
That's the path: http://k7fry.com/grid/?qth=FM18QI&from=jn49ik
Not bad for the first attempt and such a message in rather poor conds!

I believe the tests have shown that EbNaut may well be a viable QSO mode for LF and that my TX station is working well.

Implementing RX capability for EbNaut is my next goal.

Good. Winodws or Linux? :-)

In the mean time, do you see a need to continue with further EbNaut Trial transmissions from my station?

For me it is fine. And you know that it's working. In the end it is your decision, if you like, then continue.

EbNaut needs a stable phase and it could be interesting to see how regular a reasonably phase stability can be expected.
I would focus on messages taking up to 25 minutes and contain 15 characters because this could be a useful choice for later QSO modes using 30 minute sequences.

Also you never know who's trying to decode you. People are different. Some say "I'm now preparing my RX to receive you" and then "Now i am ready to receive you this night" an then "Here is my report, i have no copy because the local noise was too strong, but tomorrow the QRM should be lower because...." and so on. Other people may do the same work and have the same issues but tell nothing until they can report a successful decode! :-)
If you are on the air and offer a possibility to other to detect you, you can only rise activity, and that's most important!

73, Stefan

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