Paul,
Does this meet the criterion that you were thinking of in your comments March
21st and March 22nd?
73,
Jim AA5BW
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Paul Nicholson
Sent: Sunday, March 26, 2017 4:41 PM
To: [email protected]
Subject: LF: DK7FC in Todmorden at 2970 Hz
Stefan wrote (10th March):
> Since 16:56 UTC i'm running 180 mA antenna current > on (2970 +
> 7/(24*3600)) Hz, i.e. on 2970.000081 Hz
After coherently stacking 13:00 to 00:00 for 9 days in a bandwidth of 25.25 uHz
I get a clear signal at significance of around 5 sigma:
http://abelian.org/vlf/tmp/170326a.png
The peak has S/N 14.0 dB in 25.25uHz, which is -66 dB in
2.5kHz bandwidth. Signal azimuth is east with the expected
phase angle between E and H antennas.
The days used were 11th to 16th plus 18th to 20th. Attempting to include the
17th, or 21st to 23rd reduced the S/N.
Leaving out any of the nine stacks days also reduces the S/N.
The amplitude of each daily contribution is normalised by the average power in
a 20Hz bandwidth around the signal frequency.
No other bandwidth or daily time range produces a stronger
peak. 14:00 to 19:00 in 55.5 uHz gives about 12dB S/N.
So far, no attempt has been made to compensate for night time phase delay.
Distance is 881.2 km, approximately 8.7 wavelengths.
--
Paul Nicholson
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