Date: Sat, 5 Mar 2016 15:43:26 -0330 (NST)
From: jcraig@mun.ca
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 <Pine.LNX.4.64.1603042109500.12244@plato.ucs.mun.ca> <56DB2786.5080700@abelian.org>
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Subject: Re: LF: VO1NA - IZ7SLZ
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Status: O

My congrats to Markus, Domenico and you, Paul. My only
contribution was to throw the silly TX PSP toggle switch!

Will be QSX 137.171- 137.173 kHz with ARGO tonight.

73
Joe VO1NA

On Sat, 5 Mar 2016, Paul Nicholson wrote:

> Markus wrote:
>
>> Despite the fact that no carrier trace was visible in
>> Domenico's 0.48 mHz spectrogram ...
>
>> 1:40 UT produced a single good decode of VO1NA in South Italy
>
> Well done, I reckon that to be 5418 km.   I expect that record
> will stand for some time.
>
> The signal was -45dB in a 2.5kHz audio bandwidth and had a dB
> or two to spare.  I don't think it would have decoded with
> one second symbols.
>
> Decodes at DF6NM 2016-03-02/03:
>
>> start  car. sym. offs.
>>  UT    dB   dB   mHz
>> 23:30 11.9  7.9   0
>> 00:00 12.9  10.0 -1.5
>> 00:30 16.1  13.6 -1.5
>> 01:00 11.6  8.3  -1
>> 01:30 16.9 14.2  -0.6
>> 02:00 10.7  8.3  -0.6
>> 02:30 17.9 14.4  -0.6
>> 03:00 14.1 10.8  -0.6
>> 03:30  5.7  4.4  -0.8
>> 04:00  5.2  5.1  -0.8
>> 04:30  3.6  4.0  -0.8
>
> Signals look to be 10dB up compared with recent nights.  We're
> seeing the now familiar discrepancy between Eb/N0 calculated
> from the carrier S/N and the BER which suggests the phase
> isn't very stable and these tests are probably at the limit
> of what can be done at MF with message durations of this length.
>
> Markus is probably right with the suggestion that there is a
> maximum message duration related to the propagation spreading
> and it is likely to be typically just a very few minutes but
> I wonder how it varies with distance.
>
> This achievement represents considerable effort and patience
> by Markus.   Few of these decodes would have been successful
> without spending a lot of time searching for the correct
> frequency offset.  For example a 0.6mHz offset is nearly a
> whole cycle of phase shift on the 752*2 second messages which
> is well beyond the range of the phase search of the decoder.
>
> Today I put up another 150m metres of wire here.  I would
> have got more done but for a tendency to sit amongst the trees
> taking in the winter scenery in the sunshine.  It is very nice
> to be in the woods putting up wire and only hunger and darkness
> forced me back indoors.
>
> --
> Paul Nicholson
> --
>
>