Yes Roger, sorry, but he did not receive me. Sorry Alexander. But as i wrote it
was a first test and as we know from LF: The RX side is also important, just as
the TX side. And my signal was 23dB weaker than calculated! One can say "I can
excellent see the alpha stns" but may anyway have a bad RX antenna. So it may
be difficult to evaluate this unless one has no amateur signals to receive...
But we will do the job! Surely!
Markus/DF6NM, help us! ;-) Take some days for VLF-holidays or spend the weekend
;-)
73, Stefan/7FC
________________________________
Von: [email protected] im Auftrag von Roger Lapthorn
Gesendet: Mi 03.03.2010 18:43
An: [email protected]
Betreff: Re: AW: LF: VLF TX experiments_short report
Stefan,
If I understand correctly, DF8ZR was listening for your 8.9kHz signal but did
not receive you. Is this correct?
73s
Roger G3XBM
2010/3/4 Alexander S. Yurkov <[email protected]>
On Tue, 2 Mar 2010, [iso-8859-1] Stefan Sch?fer wrote:
>
> Yesterday the wind was suitable and the sun was out :-) So i was on the
hill
> and did the first test. I even had an oscilloscope there to measure the
> antenna voltage and current waveforms. Some photos of the arrangement
> will be shown on my site at qrz.com <http://qrz.com/> in some days (sri,
have forgotten
> cable between camera and PC...)
> I just had 1,6kVrms on the wire. That is 23dB less than calculated but it
> was a first test. So, the ERP was just 1/200. Additionally i have
> forgotten a part of the ground radial wich increased the earth
> resistance. Bernd/DF8ZR received in a distance of abt 16km
Anyway this is a new record on 9 kHz:-) Congadulations! Remember, this is
well out of near reactive zone. Thus field decreases as 1/D and if you
increase voltage to 20 kV then distance will be 20:1.6=12.5 times more.
16*12.5=200km. You can see this first test corresponds
well with previous calculations (it SHOULD be abt 16 km with such a
voltage if 20 kV yelds 100-200 km). Factually you got first experimental
insurance of the calculations. Besides real distance may be more then
200km because of ionosphere influence on such distances. All of this is
very interesting.
Regards,
Alexander/RA9MB
--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk <http://www.g3xbm.co.uk/>
http://www.youtube.com/user/G3XBM
G3XBM GQRP 1678 ISWL G11088
<<winmail.dat>>
|
