Re: LF: EbNaut March 30/31

[Markus Vester <markusvester@aol.com>]

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

k3rwr_df6nm_180331_logs.txt
Description: Text document