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Bob,
how about a straight carrier on 29.499, from 14 to
16 UT? The narrow grabbers will be on even if I have to be away.
Results may depend on the qrn situation here (aka Eu weather).
73, Markus
Sent: Friday, March 07, 2014 10:29 PM
Subject: RE: LF: New OPERA OP/OPDS 2H tonight on 27.945 Dial
Freq...
Markus; With you home [not at work] tomorrow lets
try around that 1500. I left the signal on two nights ago till 1200 but
after 0800 signal was gone till 2400 next night. What mode and what
time you want signal? Bob
From: [email protected]To: [email protected]Date:
Fri, 7 Mar 2014 21:45:19 +0100 Subject: Re: LF: New OPERA OP/OPDS 2H tonight
on 27.945 Dial Freq...
Jim,
I would think that the main difference between
Todmorden and Nuernberg is that I'm into the sunrise dip an hour earlier. And my
noise background is higher, so I tend to completely lose a weak signal which
Paul would still receive well.
Anyway looking at the attached NAA plot I'm sort of
perplexed by the strong propagation during the day. If Bob decided to
transmit sometime around 15 UT, there's a good chance we'd pick it
up.
Best 73,
Markus (DF6NM)
Sent: Friday, March 07, 2014 8:57 PM
Subject: RE: LF: New OPERA OP/OPDS 2H tonight on 27.945 Dial
Freq...
Bob
and Markus,
Thanks,
this seems consistent with the shape of the late-night/early-morning amplitude
characteristic in the LWPC simulation (for 43N, 75W to Todmorden) that Paul sent
to the group on March 1, 2014: a smooth, fast transition (and particularly with
minimal multimode peak/null effects).
It’s
interesting to note this characteristic (for this month, frequency and path),
but more interesting to note consistency of Paul’s LWPC result with last-night’s
data.
I
don’t think that the difference in paths from Bob’s location to Todmorden and to
Markus’ location should make much difference in the shape of the
late-night/early-morning amplitude characteristic, but I could be
wrong.
In
another example of rough agreement between VLF models and test results in this
group’s efforts (for roughly similar paths and times of year): the shape and
magnitude of the phase characteristic measured by Paul (for 43N, 75W to
Todmorden) overnight March 1st/2nd was consistent with a
published model (Chilton 1964, based on empirical data) for a path of roughly
similar land distance and water distance. The diurnal phase characteristic for
paths of this length and orientation (43N, 75W to Todmorden) varies considerably
month by month, so it was most interesting to see the close correspondence
between Paul’s March 1st/2nd measurements and
Chilton’s 1964 results for a different but analogous transatlantic path in early
March.
73,
Jim AA5BW
Markus;
I closed at 0820 as I saw
the signal went away at about 0700 on the Markus grabber. Had to be up
early so couldn't stay on longer. Will stay on longer
tonite-Bob
From: [email protected]
To: [email protected]
Date:
Fri, 7 Mar 2014 11:37:49 +0100
Subject: Re: LF: New OPERA OP/OPDS 2H tonight
on 27.945 Dial Freq...
I dont really know
when Bob switched off... On my grabber, the signal dropped sharply around 6
UT, thus the correlation peak was probably based on the first half of
the sequence which ended 6:52. But on Paul's spectrogram http://abelian.org/vlf/sg29499.shtml the carrier stayed
visible until after 8 UT.
Sent: Friday, March 07,
2014 9:28 AM
Subject: RE: LF: New OPERA
OP/OPDS 2H tonight on 27.945 Dial Freq...
Markus,
This
is a welcome sight. Thanks to you and Bob. Was this detection made approximately
ten minutes before Bob switched off?
73,
Jim AA5BW
Just one detection
here, but that makes it worth the effort:
2014-03-07 06:52:02
WH1XBA 6448km 29499.000Hz 1mHz -52.9dBOp 100%
15.3dB
Out of the last four
nights, this was the one with the highest noise. The carrier was visible
since about 0:30, but the detection occured only in the morning when the noise
went down before the signal did. Unlike Paul in Todmorden, I don't have a
steerable pair of loops, so only the blanker to combat the statics.
Bob, thanks for this
signal!
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