Re: LF: NA VLF

[Markus Vester <markusvester@aol.com>]

Fantastic! Joe's first long transmission is immediately being picked up over the ocean - what a start, at 10 uW! 

Big congratulations to Paul and Joe, and also to Mike for confirmation from his antenna.

All the best,
Markus (DF6NM)


-----Ursprüngliche Mitteilung-----
Von: Paul Nicholson <vlf0403@abelian.org>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mo, 8. Mai 2017 22:01
Betreff: Re: LF: NA VLF

Watson-Watt calculation from the antenna amplitudes and phases
of the overnight signal gives 244 degrees which is reasonable
given the background noise from the south west (pulling the
apparent bearing southwards from the great circle 280 deg).

Without any calculation, I can see from the relative antenna
phases that the signal is from the west: the E/W H-field is
very obviously inverted (relative to the E-field) from its
familiar polarity on European signals.

Joe wrote:

> The carrier was generated with an undisciplined 10 MHz DOCXO
> clocking an ad9851. As Markus points out, the maths puts it
> high by 92.5 uHz.

Overnight signal peaks at 8270.0070625 Hz +/- 0.5 uHz.
Therefore about 3.6 ppb low of the DDS nominal frequency of
8270.0070925...

If I align the FT bins with that frequency, the overnight
signal becomes a sharp line -

http://abelian.org/vlf/tmp/170508e.gif

with a respectable S/N of 13.9 dB in 46.296 uHz.

I'm now confident that this little peak in the spectrum
is 10uW from VO1NA. Distance is 3545 km.

The signal amounts to about 2.6 electrons on the E-field probe.
How's that for a signal report Joe?

Also getting a bit of a signal visible at Forest, Virginia.
Not a very significant peak but it has the same offset.
Only visible on the overnight signal, nothing yet on the
daytime. Distance to Forest is 2442 km so that's very good
for a land path.

http://abelian.org/vlf/tmp/170508d.gif

Forest is E-field only so no rejection of the South American
nighttime sferics.

--
Paul Nicholson
--