Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25;
Message-ID: <51E2D717.1090200@iup.uni-heidelberg.de>
Date: Sun, 14 Jul 2013 18:51:35 +0200
From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= <Stefan.Schaefer@iup.uni-heidelberg.de>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3
MIME-Version: 1.0
To: rsgb_lf_group@blacksheep.org
References: <CAKvcm2dpuftdtK6OdQv8fOfiw+4yQrPBQBHJ-FN2gDbT4P_oMQ@mail.gmail.com> <20130706131640.GG5246@cs.utwente.nl> <7D6B8CBB38964C9C82487F5D0F3648FC@FMVXD1232> <20130707203537.GA30691@cs.utwente.nl> <51DA00C8.6000600@iup.uni-heidelberg.de> <51DA0212.8020808@iup.uni-heidelberg.de> <51DA03CE.6020508@iup.uni-heidelberg.de> <51DA1680.6030602@iup.uni-heidelberg.de> <51DB6CB3.2080708@iup.uni-heidelberg.de> <001601ce7c95$f235b360$6401a8c0@JAYDELL> <51DBFF7D.9050807@iup.uni-heidelberg.de> <51DC58E9.5030005@iup.uni-heidelberg.de> <51DF1D06.8020208@iup.uni-heidelberg.de> <51DF43E7.8080300@iup.uni-heidelberg.de> <op.wz4k19tayzqh0k@pc-roelof> <51E147E2.8080302@iup.uni-heidelberg.de> <002701ce7ff5$714bc830$53e35890$@nifty.com> <51E1DDDF.3020904@iup.uni-heidelberg.de> <op.wz7hsj1jyzqh0k@pc-roelof> <001501ce8098$51e6af20$f5b40d60$@nifty.com> <51E2B2D5.5090805@iup.uni-heidelberg.de> <001c01ce80a7$03d1add0$0b750970$@nif! ty.com> <51E2D3D1.4020400@iup.uni-heidelberg.de>
In-Reply-To: <51E2D3D1.4020400@iup.uni-heidelberg.de>
Subject: Re: LF: Re: MiniWhip antenna, fiber optic /p tests
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: quoted-printable
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Status: O

Sorry, the time in the list is wrong. It is not UTC but local time which=20
is UTC+2 here now.

73, Stefan

Am 14.07.2013 18:37, schrieb Stefan Sch=E4fer:
> MF,
>
> I just came back from a field experiment, using the short active=20
> dipole which is resonated to 475 kHz (4.7 mH and 10 mH fixed inductors=20
> in parallel plus a few pF (<10) for fine adjustment), with fiber optic=20
> cable.
>
> Tests were done in JN49HK94RW, a distance of 2.3 km, see=20
> http://no.nonsense.ee/qthmap/?qth=3DJN49HK94RW&from=3DJN49IK00WD Since =
it=20
> was 17 AM local time i assume there was no skywave component. The=20
> location is an open field without trees or houses in a radius of at=20
> least 30m and without electricity in a radius of at least 100m.
>
> Some results were interesting for me. However i have to do the test=20
> again because my own signal was so strong that some measurements=20
> overloaded the soundcard. I have to reduce the power by 30 dB or so in=20
> the next test, or i have to choose another location.
>
> The signal levels were shown in my battery powered netbook using=20
> SpecLab Software. Noise measurements were done in 1 Hz NBW.
>
> I do not have a high and stable plastic pole so it was just possible=20
> to do the test in 1.75 m above the ground. Tests were done in a=20
> horizontal and vertical position of the dipole. For the horizontal=20
> test i tried both, poiting of the dipole to the TX location and 90 deg=20
> rotated to it. There was no difference. The tests were done with a=20
> floating and a grounded dipole (grounded to a local earth rod, just=20
> 10cm into the soil).
>
> Images:
> https://dl.dropboxusercontent.com/u/19882028/MF/20130714_165114.jpg=20
> (Receiver)
> https://dl.dropboxusercontent.com/u/19882028/MF/20130714_170616.jpg=20
> (Vertical)
> https://dl.dropboxusercontent.com/u/19882028/MF/20130714_165421.jpg=20
> (Horizontal)
>
> Results are attached in the image.
>
> Now we can discuss about the results, or not :-)
> As i said, i have to repeat the test because a few of the measurements=20
> were to close to the soundcards ADC limit and caused nonlinearity...
>
> 73, Stefan/DK7FC