Hi Dimitris,
Am 07.02.2019 22:59, schrieb Dimitrios Tsifakis:
You must have a much larger antenna than me as in my current 140 m^2,
3-turn loop, I can reach a bit over a 1 uW with a 1 kW input!
On which frequency? Didn't you tell about a 120m x 3m single turn loop?
There
are many physical limitation that cannot be exceeded that will never
allow me 200 uW with this antenna. Of course, that's just the start,
once I get some success, I will be looking for larger antennas (and I
do have some ideas which extend past my fence).
One of the first steps could also be to place a receiver in the far
field, a good receiver. You are working in Canberra, right? So you can
place a RX there and make a webpage showing spectrograms?
Ah BTW are you skilled with Linux or do you arlready know that you'll
never give it a try?
You know the
addiction!
Hehe, yes!
I already looked arround in your location. It is a QTH for dreamers!
You know the history about the 'DREAMERS'? ;-)
What is that stuff in QF44OX02XI
? Is it water? Or there in QF44OX01US ? Water,
that is water! Horray!! There you could throw some wire into, your
aluminium wire.
Oh and here in QF44NW99XV
That's excellent! There is just a little effort and you will be able to
leave a trace on Edgars RX, TXing with 200 uW.
If you can lay a wire from here to there, see
http://k7fry.com/grid/?qth=QF44OX01US&from=QF44NW99XV that's 1000m
already and you can get a good conductivity. Try to find metallic
plates, maybe 1 sqare metre. That could work fine. 1 km is not so much,
you could even roll it up again after transmitting.
It would be interesting to see how much current you can get at DC or at
various frequencies up to 30 kHz.
Anyway, my plan is to start at 29.999 kHz (the entrance to VLF!)
first. My antenna works a lot better on that frequency. I will them
move down in frequency. For the legal limit of 7.5 uW, what distance
would you expect a QRSS10 signal to cover at 29.99 kHz? We'll find out
this weekend but I can start taking bets today! :-)
If you have a well working RX, sensitive antenna, both H field, the
right position and 'no' nearby QRM sources, it think you can make 10
km. That's my guess, without doing calculations.
If you run 50 uW on 17.47 kHz (Edgar is skilled on that frequency!) you
will reach Edgar, if your loop points into his direction. If you can
run just 500 mA into that 1 km long wire, on that frequency, you will
be there!
Do you have enough wire for the weekend? :-) I use that cheap CCA
loudspeaker cable which has 0.75 mm2. A 100m ring (i.e. 2x 100m) costs
about 13 EUR here, quite affordable.
73, Stefan
73, Dimitris VK2COW
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