LF: Re[2]: LF: EbNaut March 31 / April 1

[Alex K <rn3aus@gmail.com>]

Hello LF, Markus, Ric

I downloaded opds *.txt file from my old automatic LF-grabber in KO85fn http://rn3aus.136.su/grabber.html 
and then I have some decodes of ebnaut transmissions df6nm and iw4dxw last night.
Unfortunately noise level from energy-saving lamps around grabber is very high at night time. So only morning time give me decode...

73 de rn3aus/Alex

Воскресенье, 1 марта 2018, 2:20 +03:00 от Markus Vester <markusvester@aol.com>:

Hi Ric,

your transmission extends four minutes beyond mine, long enough to decode it here after my TX went off ;-) Note that the apparent frequency was slightly off because my RX instance takes a few minutes to reaquire samplerate lock.

Best 73 and Happy Easter,
Markus


-----Ursprüngliche Mitteilung-----
Von: Riccardo Zoli <riccardozoli80@gmail.com>
An: LF Group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 1. Apr 2018 0:58
Betreff: Re: LF: EbNaut March 31 / April 1

 QRG: 137522.000313 Hz

Il Dom 1 Apr 2018, 00:13 Riccardo Zoli <riccardozoli80@gmail.com> ha scritto:

Ok, Markus! Here, first transmission delayed at 2200 UTC (now running).

Then:

message start on hour (xx:00);

8K19A, CRC 20, 3 sec/sym, 6 char, duration 29' 36"

GN 73 de IW4DXW

Il Sab 31 Mar 2018, 23:46 Markus Vester <markusvester@aol.com> ha scritto:

Hi Ric, all,

if I can get it all to work I will join you tonight:

137520.000 Hz, 5 char, 8K19A CRC 16, 3 second symbols, start time 22:00, 23:00 etc (first half hour), duration 0:25:36

Hope that 2.00 Hz spacing (orthogonal modulation) between us will be ok as we are both on the European side.  

A test transmission has started at 21:30 (i.e. second half hour)

Best 73,
Markus (DF6NM)

-----Ursprüngliche Mitteilung-----
Von: Riccardo Zoli <riccardozoli80@gmail.com>
An: LF Group <rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 31. Mrz 2018 16:24
Betreff: Re: LF: EbNaut March 30/31

Hi Markus, LF

Yes, 5 Hz are quite indequate for simultaneous EbNaut transmissions.

Anyway, I switch in RX on the second half of every hour. Rob is working for RX capability, then, once he's ready, we could exchange TX and RX slots.

QSY for me this evening at 137522.000313 for another TA attempt (many thanks, Jay) with same EbNaut parameters and scheduling.

All the best

73 de Riccardo IW4DXW

 

Il Sab 31 Mar 2018, 14:07 Markus Vester <markusvester@aol.com> ha scritto:

Again a strong signal with some error-free decodes from IW4DXW. Also found K3RWR finally on 137490 Hz, but only once after 4:00, and another near-miss around sunrise after 4:30 (logs attached).

Rethinking my frequency suggestion, it may not be ideal to place simultaneous signals from both sides of the pond so near to each other. EbNaut employs hard-keyed phase switching both for the transmitter and for the matched filter in the receive software, so keying sidebands or aliasing from a near station may spill over an adjacent weak signal (although in principle this could be minimized by orthogonal modulation, using identical symbol timing for all stations, and frequencies spaced by an exact integer multiple of the common clockrate). But there are also other disadvantages, like noise-blanker induced crossmodulation and threshold increase. So in the end it may be better to use either separate timeslots or separate subbands, in analogy to our TA- and Eu-QRSS slots.

Best 73,
Markus (DF6NM)


-----Ursprüngliche Mitteilung-----
Von: Markus Vester <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Fr, 30. Mrz 2018 23:03
Betreff: LF: EbNaut March 29/30

Last night Mar 29/30, I got excellent decodes from IW4DXW, but unfortunately not a single one from K3RWR on 137490 Hz.

Best 73,
Markus (DF6NM)
______________________________________
LF: EbNaut attempt at 137495 kHz 
Von: Riccardo Zoli <riccardozoli80@gmail.com>
An: LF Group <rsgb_lf_group@blacksheep.org>
Datum: Do, 29. Mrz 2018 19:53

Hi LF

This night, I have scheduled some transmissions every hour (start at xx:00).

QRG: 137494.99988
8K19A
CRC 20
3 sec./sym.
6 char
duration: 29 min. 36 sec.

Reports are welcome.

All the best

73 de Riccardo IW4DXW
______________________________________
Re: LF: K3RWR LF EbNaut Trial #2 
Von: Rob Renoud <k3rwr@md.metrocast.net>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Datum: Do, 29. Mrz 2018 21:22

TU all for LF EbNaut reception reports for my 28/29 March 2018 trial of a 12 char, CRC 15, 2 sec symbol 8K19 transmission.  The first night results of this format are very positive!

I will transmit this format again this evening (29/30 Mar) and tomorrow (30/31 Mar) on frequency 137.490 KHz.

Reports and comments welcome.   Work is starting this weekend on EbNaut RX capability for my station.

73,
Rob - K3RWR

df6nm.png
Description: PNG image

IW4DXW.png
Description: PNG image