Hi Markus,
Yes, it did seem valid... But we will continue to try. Tonight
a 3 character message, 8K25A polynomial, 464 symbols 55 seconds long
starting 2300 tonight and 1100 tomorrow morning.
Please excuse my efforts at humour concerning QRM. If the
Anerican Navy would permit access to tune the NAA antenna to 8270.007 Hz
then perhaps Stefan might get a bit of competition.
Keep up the amazing work on ULF Stefan.
73 Joe VO1NA
On Tue, 23 May 2017, Markus Vester wrote:
D'oh, pity! That message sounded so plausible, and at 0.5 dB EbN0 I wasn't
suspecting a false decode.
Joe, could you perhaps remind me of your EbNaut timing parameters again? I seem
to have missed an email mentioning them.
I don't think that mutual QRM would have been much of a problem. The two
signals would be perfectly orthogonal if you used identical symbol timing and
chose a carrier frequency spacing which is a multiple of the inverse symbol
period (i.e. 0.05 or 0.1 Hz for Stefan's 20 s symbols).
Best 73,
Markus
-----Ursprüngliche Mitteilung-----
Von: jcraig <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Di, 23. Mai 2017 17:12
Betreff: Re: LF: NA VLF
Paul and Markus,
Thank-you for the encouragement and patience, but infortunately the
message received does not match the one that was sent, assuminmg the
sending was done correctly. Can we try again?
Hopefully I am not causing QRM to Stefan's QTC on 8270.1 Hz. If so I can
QSY back to 8277 Hz! Can we try his suggestion for a daytime attempt to
take advantage of the lower QRN or will the S/N be too low?
Also, are the sigs stable enough? Stefan suggested a GPS module that
could be used with Spec Lab to generate a disciplined carrier. The WX
should be more stable now. Last night the ERP decreased and the phase
probably shifted too.
73
Joe VO1NA
On Tue, 23 May 2017, Markus Vester wrote:
Paul and Joe,
great news! Your patience has finally paid off. Congratulations to both on this
excellent piece of work!
73,
Markus (DF6NM)
-----Ursprüngliche Mitteilung-----
Von: Paul Nicholson <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Di, 23. Mai 2017 12:07
Betreff: Re: LF: NA VLF
Overnight 22nd/23rd was fairly quiet and the decoder turned up
'VO!'
at Eb/N0 = +0.5dB, BER 42.7% with constant reference phase,
peaking at frequency of 8270.0070925 Hz + 6 uHz.
Rank 7430 in the decoder list.
Carrier S/N: 12.81 dB in 39.2 uHz,
-31.26 dB in 1Hz,
-65.24 dB in 2.5kHz
--
Paul Nicholson
--
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