Re: LF: AW: EbNaut Test tonight

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

Hi LF, Ebnauters, Group

i my previous post, i have communicated a wrong information about EbSynch  and i'm very sorry for this. Many thanks to Markus Vester for his clarification in a private mail.

I wrote:   EbSynth also cures soundcard's glitches by using an internal feedback.

That is not true. As clearily indicated by Paul Nicholson on the webpage http://abelian.org/ebnaut/ebsynth.shtml, an external feedback signal may be connected to the channel 2 of the soundcard  to stabilise the phase.

On my setup,  the  -x option is not specified (internal feedback active) and i have only a 10 kHz reference signal connected on channel 1. Phase recover cannot be done with the 10 kHz tone alone because the phase,  after a dropout or buffer overflow,  would be ambiguous.

From P.N. website

Sound card overruns and underruns must at all costs be avoided. If one occurs, the phase will be lost and there is no way to recover. If the ALSA driver reports overrun on input or underrun on the output ebsynth will exit. There is no point in trying to recover. USB sound dongles may lose USB packets and the driver is not notified. If this happens on the reference input the phase will be lost and will not recover. The output will experience a phase step and will settle down at a new phase. If a USB packet is dropped from the output, there will also be a phase step but if external feedback is in use, the phase will recover to its original value.

Sorry again for my error.

My night '114 characters' trasmissions were completed at 05.00 UT . I hope in a report. Thanks to whom have attempted the decode.

All the best

Domenico Lindo / IZ7SLZ

On 19 April 2018 at 00:19, Domenico IZ7SLZ <iz7slz.domenico@gmail.com> wrote:

Hi LF

first of all, thanks to Stefan and Marco for reports and to the US' friends for their efforts in trying to decode my  5 characters message of yesterday.

The Ebnaut signal is generated here using Paul Nicholson's linux EbSynth version 0.7c.

This program generates a 1524 Hz tone (referenced by a 10 kHz coming from Neo-8 GPS) bpsk modulated with a sigmoid phase slew keying. EbSynth also cures soundcard's glitches by using an internal feedback. Thanks to Paul latest modifications, 'EbSynth' has also a PTT management with a programmable timer for carrier ON/OFF before and after bpsk.  See attached the screenshot of the program EbSynt running here.

Great job Paul !

The tone is sent to my 'vintage' SAILOR exciter setted to dial 136 kHz USB.

The exciter has an internal 10 MHz ref. oscillator referenced to the same GPS 10 kHz.

Another EbNaut attempt tonight until 06.00 UT of April 19, 2018

Characters 115

Symb 0.3 s

code 8K19A, CRC16

duration 28:28.80

every hour at XX:00

73, Domenico IZ7SLZ

On 18 April 2018 at 17:29, DK7FC <selberdenken@posteo.de> wrote:

Hi Domenico,

No problem to copy the 5 char message, see attachment.
I tried to decode the 200 char message but get no decode. Can you try 8K19A and 100 characters first? It looks like it was to early in the night for that message, 1 hour later the propagation is better it seems.
Are you using SpecLab for transmitting the message or ebsynth?

73, Stefan

Am 18.04.2018 01:11, schrieb Domenico IZ7SLZ:

I wrote:

-----
Then 5 characters every xx.00 and xx.30 until tomorrow 06.00 utc 

Code 8k19A crc 16

Symb 4s 

Duration 28':00""

-----

Sorry there is a mistake:

5 characters every hour at xx:00

Code 8k19A crc 16

Symb 4 s

Duration 34:08

First attempts already on air.

GL de Domenico IZ7SLZ

On Tue, 17 Apr 2018, 23:25 Domenico IZ7SLZ, <iz7slz.domenico@gmail.com> wrote:

Hi LF,

A 200 characters message will be on air at 21:30  and at 22.00 UT 

Code 4k19A crc 16

Symbol 0.3 s 

Duration 24':40'',80

Then 5 characters every xx.00 and xx.30 until tomorrow 06.00 utc 

Code 8k19A crc 16

Symb 4s 

Duration 28':00""

Qrg is 137524.0000 Hz

Reports are welcome.

73 Domenico IZ7SLZ