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Date: Fri, 25 Sep 2015 12:23:40 +0100
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From: Andy Talbot <andy.g4jnt@gmail.com>
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Coherent BPSK on LF using EbNaut
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EbAnut is a new one here - I hadn't heard of it.   After Googling I found
the page and read up / downloaded the software.   Unfortunately, I see it
is not standalone, and requires Spectrum lab to act as the audio "front
end" to take in the Received audio, downconvert to a baseband I/Q and store
that as a .WAV file.   So downloaded Spectrum lab and tying to wade through
how to use that.

Could you perhaps give a short cut simple explanation of how to set up
Spectrum lab to do that - it looks to be a very complex bit of software to
drive.
the EbNaut Tx and Rx programmes, in contrast, look very simple to use and
it would be goo dto get more people using sensitive coherent signalling
such as this.

Some years ago I proposed GPS / UTC seconds locked coherent signalling on
LF, but didn't have the expertise to write the software - and certainly not
to implement strong FEC !

Andy  G4JNT


On 23 September 2015 at 01:04, IZ7SLZ <iz7slz.domenico@gmail.com> wrote:

> Hello LF,
>
> I am pleased to report a successful "Coherent BPSK" QSO between DF6NM and
> IZ7SLZ on LF using EbNaut program of Paul Nicholson.
> QSO took place in the night between Friday 2015-09-18 and Saturday
> 2015-09-19 .
>
> I think it was the first time that anyone tried this on 137 kHz !
>
> Frequencies used were 137510.00 Hz (DF6NM) and 137502.12 (IZ7SLZ).
>
> We exchange messages of 16 characters in coherent BPSK with UT synchronous
> symbols, using a symbol period of 1 second and 8K19A scheme coding.
>
> Software used were the Windows' versions of EbNaut-TX and EbNaut-RX (tnx
> to P. Nicholson: your software is working without problems!).
> Also Spectrum Lab (tnx Wolf !) was used to export FFT data, in a similar
> way of the Markus' OPDS setup.
> Other programs,  written by Markus,  were used: one  to convert FFT
> exported data for the EbNaut entry and another to search for the best
> frequency and time offsets.
>
> There was not much phase drift during the qso and in other test
> transmissions, since we reach a good frequency stability at both ends
> thanks to Rubidium Reference Oscillator (Markus side) and a good quality
> OCXO from my side.
>
> You can see reported symbol / carrier EbN0 and also the messages
> exchanged,  in the attached screen-shots taken at both ends.
>
> We hope now to joint other stations that want to challenge the timing and
> frequency accuracy, to have a QSO in LF close to the Shannon limit.
>
> Markus DF6NM, will report soon all particulars and his comments of the
> experiment. Thanks in advance Markus!
>
> 73, Domenico (iz7slz)
>
>
>
>

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<div dir=3D"ltr"><div>EbAnut is a new one here - I hadn&#39;t heard of it.=
=C2=A0=C2=A0 After Googling I found the page and read up / downloaded the s=
oftware.=C2=A0=C2=A0 Unfortunately, I see it is not standalone, and require=
s Spectrum lab to act as the audio &quot;front end&quot; to take in the Rec=
eived audio, downconvert to a baseband I/Q and store that as a .WAV file.=
=C2=A0=C2=A0 So downloaded Spectrum lab and tying to wade through how to us=
e that.</div><div><br></div><div>Could you perhaps give a short cut simple =
explanation of how to set up Spectrum lab to do that - it looks to be a ver=
y complex bit of software to drive.</div><div>the EbNaut Tx and Rx programm=
es, in contrast, look very simple to use and it would be goo dto get more p=
eople using sensitive coherent signalling such as this.</div><div><br></div=
><div>Some years ago I proposed GPS / UTC seconds locked coherent signallin=
g on LF, but didn&#39;t have the expertise to write the software - and cert=
ainly not to implement strong FEC !</div><div><br></div><div>Andy=C2=A0 G4J=
NT</div><div><br></div><div class=3D"gmail_extra"><br><div class=3D"gmail_q=
uote">On 23 September 2015 at 01:04, IZ7SLZ <span dir=3D"ltr">&lt;<a href=
=3D"mailto:iz7slz.domenico@gmail.com" target=3D"_blank">iz7slz.domenico@gma=
il.com</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" style=3D"=
margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204=
);border-left-width:1px;border-left-style:solid">Hello LF,<br>
<br>
I am pleased to report a successful &quot;Coherent BPSK&quot; QSO between D=
F6NM and IZ7SLZ on LF using EbNaut program of Paul Nicholson.<br>
QSO took place in the night between Friday 2015-09-18 and Saturday 2015-09-=
19 .<br>
<br>
I think it was the first time that anyone tried this on 137 kHz !<br>
<br>
Frequencies used were 137510.00 Hz (DF6NM) and 137502.12 (IZ7SLZ).<br>
<br>
We exchange messages of 16 characters in coherent BPSK with UT synchronous =
symbols, using a symbol period of 1 second and 8K19A scheme coding.<br>
<br>
Software used were the Windows&#39; versions of EbNaut-TX and EbNaut-RX (tn=
x to P. Nicholson: your software is working without problems!).<br>
Also Spectrum Lab (tnx Wolf !) was used to export FFT data, in a similar wa=
y of the Markus&#39; OPDS setup.<br>
Other programs,=C2=A0 written by Markus,=C2=A0 were used: one=C2=A0 to conv=
ert FFT exported data for the EbNaut entry and another to search for the be=
st frequency and time offsets.<br>
<br>
There was not much phase drift during the qso and in other test transmissio=
ns, since we reach a good frequency stability at both ends thanks to Rubidi=
um Reference Oscillator (Markus side) and a good quality OCXO from my side.=
<br>
<br>
You can see reported symbol / carrier EbN0 and also the messages exchanged,=
=C2=A0 in the attached screen-shots taken at both ends.<br>
<br>
We hope now to joint other stations that want to challenge the timing and f=
requency accuracy, to have a QSO in LF close to the Shannon limit.<br>
<br>
Markus DF6NM, will report soon all particulars and his comments of the expe=
riment. Thanks in advance Markus!<br>
<br>
73, Domenico (iz7slz)<br>
<br>
<br>
<br>
</blockquote></div><br></div></div>

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