Paul,
That’s so exciting I created a folder in anticipation of data next winter.
For those events I can provide spectrograms from 2 fT/rt-Hz receivers near
Atlanta GA and Gainsville, FL; they run continuously.
Today I'll see about an Atlanta spectrogram for Joe's signal (7 April through
today?)
Thanks also for the info on (a) terminator Doppler and (b) your phase/amplitude
Watson-Watt AoA measurement.
73,
Jim AA5BW
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Paul Nicholson
Sent: Thursday, May 11, 2017 3:23 PM
To: [email protected]
Subject: Re: LF: NA VLF
LWPC claims 7.2 dB anisotropy on the VO1NA to Todmorden overnight path. That
means east-to-west is only 7.2dB more loss than west-to-east.
For VO1NA to DK7FC the anisotropy is only 5.6 dB. Also VO1NA at Heidelberg is
only 2.8 dB weaker than VO1NA at Todmorden.
These figures suggest that with a good rx at Torbay, a first T/A east-to-west
and a 2-way T/A QSO is within reach.
Perhaps something for the long Winter nights.
VO1NA seems to be stable on 8270.0070093 since that first night.
Perhaps we saw some DOCXO warm-up drift.
Overnight 9th/10th the best signal was between 00:00 and 06:00, about 13dB S/N
http://abelian.org/vlf/tmp/170511a.gif
Overnight 10th/11th the signal was hardly visible against the noise, it was a
noisy night. The noise was enough to bury a
0.06 fT signal.
It appears the overnight signal is clearly detected on about half the nights.
As I walked past the E-field antenna yesterday, I paused for a moment to
contemplate the 1.4 electrons currently being jostled by the field from Joe's
transmitter at the other side
of the Atlantic. I could see Pendle Hill 24km away and tried
to imagine the transmitter 150 times further away.
Jim wrote:
> have we seen natural-propagation-related frequency changes > on this
> timescale?
The most rapid changes are during the terminators, LWPC predicts a deviation of
25 uHz for about 4 hours as the terminators cross the Atlantic. Outside those
periods it should be stable within a few uHz, say within 5uHz. The T/A signal
from W4DEX was stable away from the terminators.
Joe wrote:
> The sigs will continue until the helix sparks or the wx grounds > the
> aerial.
Well I think I've got all I can get out of this signal for now.
It's not strong enough to measure how the phase is varying during the night or
day. This weekend I'll have time to take a closer look at the recording.
--
Paul Nicholson
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