Hi Dimitris,
Am 04.02.2019 06:54, schrieb Dimitrios Tsifakis:
[...] and pity you are not
closer otherwise [...]
Indeed. Otherwise we could do some VLF experiments together, maybe in
that desert close to the sea:
https://www.youtube.com/watch?v=XfR9iY5y94s :-)
Am 05.02.2019 01:16, schrieb Dimitrios Tsifakis:
Hi Stefan,
I am working on both making a portable VLF magnetic field antenna
(tuned) and a transmit antenna which perhaps will be better than the
existing 120 m by 3 m (average height) loop. The resistance of this
loop isn't stellar (about 11 ohm DCR) and half of it is aluminium
welding wire. Anyway, it's there and it is my reference antenna.
It could be a good RX antenna for VLF. Did you try to connect a
soundcard of a notebook and record something or produce a spectrogram?
You know there is Edgar from Tasmania, most probably already following
the conversation and hoping to receive something of you :-)
The
new loop antenna will be better but it is still under construction.
Heavy copper cabling is surprisingly difficult to put up in the air
with limited resources. Anyway, once all that is in place, I will do
some local tests (without rubidium or GPS locked oscillators) and
we'll take it from there. My QTH locator is QF44OX (very close to
QF44nx). I have plenty of space but it's undulating and kangaroos
always make a mess with low hanging wires!
Wow, exciting! So the RX is in QF44OX and the TX is in QF44NX?
If you have plenty of space, it may be easier to improve the ERP by
building a larger loop out of thin wire instead of a 'small' one out of
heavy wire. Maybe you can even bury the wire to avoid collisions with
kangaroos.
Is there a web page with your 8270 Hz experiments? I'd love to read up
a bit of inspiring material of what others have achieved as it can be
quite lonely doing experiments like that where I am. How much radiated
power have you achieved?
I must admit that i do not have my own homepage with up to date overview
of my VLF experiments. There is a list maintained by Paul Nicholson
giving an impression of what has been done lately on VLF/ULF:
http://abelian.org/vlf/amateur-radio/
A web page of these experiments would be very large and you could read
for hours. But i'm rather lazy writing it up, unfortunately. I'm rather
the one who puts time into winding coils!!! ;-)
Actually the whole story of all experiments is spread over the emails of
this reflector.
Your next well prepared VLF RX station is Edgar J.T. in QE37PD, see
http://k7fry.com/grid/?qth=QF44OX&from=QE37PD
With a well prepared loop, it is not unlikely at all to leave a trace on
his site! The distance is just like the distance between me and Paul
Nicholson.
But at the moment you are doing some first steps and there are some more
to be done until you reach that distance. But it is really doable!
At the transmitter site, do you have electricity or do you transmit from
batteries?
What is the power level?
Can you (temporarely) lay out a wire from here to there:
http://k7fry.com/grid/?qth=QF44NX86FC&from=QF44NX73XQ :-) This is a good
length and if configured to a loop, it would point perfectly towards
Edgar. A simple loudspeaker cable of 0.75mm2 would be fine. And you will
need some ground rods at the ends.
Sorry, that was maybe a bit much of input :-)
What do you think?
73, Stefan
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