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Hi Dave
Stefan's e-probe design for 8.7kHz antenna and sound card RX. The
BPF in the probe has quite some cut off outside sub 9kHz but maybe
that's good due to the adjacent big boys.
73 Eddie
On 28/11/2017 10:58, Dave wrote:
Hi,
What antenna and RX
are you using for VLF,
Eddie?
73, Dave G3WCB IO80EI
Left
it on overnight.
Would
you like it on 24/7, I see diurnal variations similar to
Marcus but more
pronounced due to my lower signal strength.
73
Eddie
On 27/11/2017
20:30, g3zjo wrote:
Hi
Stefan
I
didn't quite believe what I was reading you may like to
take a look at my
Grabber.
http://www.qsl.net/g3zjo/vlfgrabber
73
Eddie
On
27/11/2017 09:34, DK7FC wrote:
Hello
Markus,
thanks for the feedback. Wonderful, now it is 30 dB in
424 uHz. DL0AO could run
a 3.8 mHz '600' RDF spectrogram and a phase and signal
level plot, so we could
see propagation effects much better.
You could already see QRSS-60 from me! I will try that
soon.
The carrier is still on the air. It will run the whole
day and night...
73, Stefan
Am 26.11.2017 15:59, schrieb Markus Vester:
Hi VLF,
Since 23 UTC a 700 mA carrier is running on 17.4701
kHz!
It is a little surprise to the VLF community i
think ;-)
Legal? Yes: http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/17,47kHz_Sonderlizenz.jpg
Actually the document has 3 pages but the other
ones are no so relevant.
My ERP is limited to 5 mW. I did not request
more because more isn't possible
anyway with this antenna.
I wound a big single layer coil with 0.5 mm
enameled wire on a PVC tube with
315 mm outher diameter.
0.7 A is just a first careful step. The coil is
designed to hold 1.5 A 'key
down'.
The carrier will run the whole night and even
tomorrow at daytime.
Worldwide reports are welcome ;-)
It is not sub-9-kHz but still VLF, the 17 km
band!! So give it chance :-)
The tree has still some solar power to stream
the signal from the EW loop down
to the city, so there is a feedback spectrogram
at
http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html
73, Stefan
PS: I still can hear that tone of the coil. It
is terrible! Be happy when you
are older than me!
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