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Attached are four stacked spectrograms of
Uwe's signal as received by Paul Nicholson, DF6NM, OK2BVG and PA1SDB (top
to bottom), scaled to the same time and similar frequency scales. The steps
around 2 UT seem to have left a gap at OK2BVG and DF6NM. In
a direct mail, Paul has sent a series of phase measurements in half hour
intervals, which seem to corroberate the assumption of a phase step
sometime around 2 UT.
The improvements of Uwe's signal at PA1SDB
over the years is indeed impressive. Uwe, can you perhaps comment on your
antenna size and current, then and now?
Very nice work!
Best 73,
Markus (DF6NM)
Sent: Sunday, January 19, 2014 12:49
PM
Subject: Re: Re: VLF: DJ8WX 8270.004
Hz
Hi Peter,
There has been chaos around
0200utc:
2014-01-19 02:00:12 PPS
zero-crossing too flat
2014-01-19 02:00:12 Timestamp didn't
pass plausibility check !
...
I don’t know why. seems most of the
satellites where asleep.
until coming night
Uwe/dj8wx
Hello Uwe, Markus, VLF
!
I just took a "look back in
time" in my 2012 and 2013 log's (www.qsl.net/pa1sdb) and I think
over the last two years there is a large
rise in signal level when I take a
look at DJ8WX his signal. The trace in some saved Spectograms in 2012 and 2013
are not that
impressive as they are
right now.
Look at the trace in
the spectogram above. Impressive !!!
I have to do
research if those "glitches" are at the TX or RX side...
Do you recognise that
glitch at about 2 h Uwe ? (in your debug log ?)
I'm not at home this
weekend, so I can't tel you the exact time right now.
73's Peter -
PA1SDB
----- Original Message -----
Sent: Sunday, January 19,
2014 10:01 AM
Subject: Re: VLF: DJ8WX
8270.004 Hz
Hi
Uwe,
great signal here, better than ever!
On my grabber http://www.df6nm.de/vlf/vlfgrabber.htm it's
well visible in 478 uHz, and even traces in the 3.8 mHz "600" window during the
early morning hours. The SNR would probably have been sufficient for an
Opds-4H detection, but I'm glad you just left the carrier
on.
I
had fixed my frequency offset and you were spot on 8270.004, albeit with
occasional transmit phase glitches widening the 42 uHz trace a bit. Sorry
about the apparent 0.8 mHz up shift after around 3 UT, it is an
artefact caused by a too narrow setting of
samplerate tracking tolerance (0.2 ppm).
Thanks very much for this test! It's a pity that Mal hadn't left his RX
on overnight.
Best
73,
Markus (DF6NM)
Sent: Saturday,
January 18, 2014 10:56 PM
Subject: Re: VLF:
DJ8WX 8270.004 Hz
Hi Markus,
just now reading your
mail. the switch off time was some min after you sent it..
sri for
that.
now the TX will stay on the air until tomorrow abt
0900utc.
Hopefully Mal
reads this.
GL
Uwe
Uwe is
again producing very good traces on the European grabbers. Even in my noisy
location I am now getting a nice peak in the 42 uHz FFT
(slightly higher due to an uncorrected 0.25 mHz error in my
frequency readout).
Uwe, do you intend to stay on longer tonight?
Best
73,
Markus
(DF6NM)
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