Re: LF: EbNaut on LF

[Markus Vester <markusvester@aol.com>]

Hi Joe,

unfortunately I had not set up recordings in time so no data here for a decode attempt.  My LF-RX soundcard was also affected by a hiccup with swapped E and H channels until 1:30 UT. Thereafter, your signal  was well visible as a +-5 Hz wide "noise band" around 137.777 kHz, so the 0.2 s EbNaut would surely have been decodable with more than enough SNR.

Apart from going for a "longest EbNaut sequence ever" type record, I'm asking myself whether it would not be better to split a long message into several shorter ones. This probably depends both the fading pattern and on the use-case, i.e. whether a partly reception is also valuable or completely worthless. For example, if the SNR (EbN0) was +2 dB for the first half and -2 dB for the second,
you'd probably still get the combined long message but only the first of two short ones. On the other hand, if it was 0 dB and -4 dB, you'd get the first short message, but nothing at all with the long one. On the practical side, shorter messages would be far less demanding on long-term phase stability, as well as CPU and memory.

All the best,
Markus (DF6NM)


-----Ursprüngliche Mitteilung-----
Von: jcraig <jcraig@mun.ca>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 16 Aug 2016 2:47 am
Betreff: Re: LF: EbNaut on LF

QRG changed from 137.477 to 137.777 kHz at 0045 utc. Sorry for the
mixup!

73
Joe

Re: LF: EbNaut on LF
Von:	jcraig <jcraig@mun.ca>
An:	rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Datum:	Di, 16 Aug 2016 1:26 am

Dear Group,

Reports of the OP32 sigs from R7NT, F5WK, Graham, Markus, Hugh, Stefan
Dominico and others who I inadvertently left out are gratefully
acknowledged.

Tonight by popular demand starting 2330 and every 15 mins, EbNaut 155
chars 0.2 seconds 771.2 s message duration, 4K19A polynomial. 500w
3.5A to the 100m RL. Reports most welcomed. Good luck to all.
(Let's hope I've set it up correctly!)

Joe VO1NA