Signal faded out by about 07:15 UT or switched off:
2014-03-02_05:45:00 0.12 fT 9.8 deg
2014-03-02_06:00:00 0.10 fT 8.3 deg
2014-03-02_06:15:00 0.11 fT 20.2 deg
2014-03-02_06:30:00 0.13 fT 29.4 deg
2014-03-02_06:45:00 0.08 fT 28.4 deg
2014-03-02_07:00:00 0.04 fT 33.9 deg
2014-03-02_07:15:00 0.01 fT -10.9 deg
2014-03-02_07:30:00 0.01 fT -89.3 deg
Nothing else after that except background noise at 0.01 fT.
Bearing peaks roughly 280 during the first part of the night
but during the morning the signal is slightly better on 290 deg.
I leave the loop aligned on 285 for the rest of these reports.
The phase moves by around 90 deg during the whole transmission
and an integration over the full length would be weakened by
this so I made two overlapping 4-hour spectra, 00:30 to 04:30
and 03:00 to 07:00 and added them incoherently to get
http://abelian.org/vlf/tmp/29499_140302b.gif
I'm also allowing for the sferic blanker in that one so
that pushes up the average signal strength over the whole
transmission to 0.17 fT. That would correspond to about
2.4mW ERP according to LWPC. That is the average but since
the key is up for part of the time the actual ERP would
be higher still.
I tried to bring out the sidebands better by folding the LSB
over the USB to gain some statistical drop of the noise floor
but it did not make much difference.
A spectrum of the whole 6.5 hours in 42.7uHz resolution,
http://abelian.org/vlf/tmp/29499_140302c.gif
Amplitude drops to 0.16 due to the phase drift but the
S/N improves to 27.7dB.
It is feeding time here so must go. Later will make
some spectrograms to see if any Morse is visible.
--
Paul Nicholson
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