From: <hvanesce@comcast.net>
To: <rsgb_lf_group@blacksheep.org>
References: <CA+GfORvAA10STf3zWSQ-dRFwk5BBS25Ht0x8cDZ3cYTa09dYbw@mail.gmail.com> <5B54CCCB.6060903@posteo.de> <5B59E687.5030805@posteo.de> <5B5C3ABF.3030809@posteo.de> <5B5C4A63.3040504@posteo.de>
In-Reply-To: <5B5C4A63.3040504@posteo.de>
Date: Sat, 28 Jul 2018 14:43:06 -0400
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Subject: RE: VLF: Earth antenna transmissions on a guide rail?!??  NOW on the air...
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Stefan,

=20

Congratulations on new =E2=80=9CTX earth antenna league=E2=80=9D =
far-field records including 5170 Hz. Quite exciting, and impressive =
resistance values.

=20

73,

=20

Jim AA5BW  =20

=20

From: owner-rsgb_lf_group@blacksheep.org =
[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC
Sent: Saturday, July 28, 2018 6:50 AM
To: rsgb_lf_group@blacksheep.org
Subject: Re: VLF: Earth antenna transmissions on a guide rail?!?? NOW on =
the air...

=20

Update: Since 10:13 UTC i'm TXing on 5170 Hz. The antenna current is 556 =
mA and the phase looks a bit less inductive but still inductive. Despite =
beeing in the center of the Pf=C3=A4lzer Wald, i have mobile internet =
access and so i reached my Linux PC recording the VLF stream (both loop =
antennas). Using vlfrx-tools i managed to produce a spectrum peak of 17 =
dB SNR after just 30 minutes!!!! (More later) So it is possible with =
this ground loop TX antenna to transmit on 5170 Hz and beeing detected =
in about  55 km distance! :-)  These are two new records for the TX =
earth antenna league :-)
I'm going to continue transmitting on 5170.000 Hz until 11:13 UTC, then =
i'll do QSY to 2970.005 Hz which simply means i change the frequency in =
SpecLabs signal generator driving my PA! :-)

73, Stefan

Am 28.07.2018 11:43, schrieb DK7FC:=20

Hi VLF,

I'm sitting in my car while writing this email. I'm in JN39WI96GX and i =
transmit on 8270.000 Hz with a GPS locked signal generator into an about =
450 m long earth antenna using two guide rails as the earth electrodes =
on both ends. On each end there are 16 (18) massive T-T poles holding =
the guide rail, providing a super good earth coupling. I measured that =
they are connected to each other.=20
The transmitter is on the air since 9:08 UTC running 550 mA with just 75 =
W DC inout power into my hand warm lossy linear mode VLF PA!=20

I'm amazed about the low losses! At DC i got 447 mA at 50.9 V. The wire =
is 0.4 mm diameter so it has 63 Ohm. That means the ground loss is just =
50 Ohm !!!! Amazing! And i have no efforts to build up a ground =
connection here, i just need to connect the wire. Since the wire losses =
are higher than the ground losses, i can get maybe 2 dB more signal when =
buying some better wire. I already found a source that offers 0.75 mm^2 =
100 m loudspeaker cable (i.e. 200m wire)for just 13 EUR....

BTW i even have an ugly old scope here which is battery powered. I can =
see that the phase of voltage and current is slightly inductive, maybe =
30 deg or so. So i could series resonate the antenna with some C. This =
is for the next experiment...

The signal becomes visible on my grabber now, in 424 uHz and also some =
bright pixels in the 3.8 mHz window.

I'm going to stop the carrier at 10:08 UTC, after 1 hour. Then i'll =
continue on 5.17 kHz!=20
BTW the antenna , if it works like a real loop, is beaming directly to =
Paul Nicholson ;-)

73, Stefan




Am 26.07.2018 17:19, schrieb DK7FC:=20

...i just searched in the old emails and also on G3XBM's blog and found =
this entry: =
https://g3xbm-qrp.blogspot.com/2010/09/vlf-dx-transmission-with-earth.htm=
l
So that is the best distance on a transmit earth antenna (or ground =
loop) so far, at VLF, by amateurs.=20
I had a much lower earth resistance in mind but actually i just got 0.53 =
A at 250 W RF power, so the losses were rather 890 Ohm!
Will it be possible to make 55 km distance at 8.27 kHz, maybe in a lower =
bandwidth like 424 uHz, with power levels in the range of 50 W only?

73, Stefan

Am 22.07.2018 20:28, schrieb DK7FC:=20

Hi all,=20

During the weekend i am in the Pf=C3=A4lzer Wald again which is such a =
nice place to be! I already installed a fixed E field antenna for =
VLF/ULF reception in JN39XI06  <http://k7fry.com/grid/?qth=3DJN39XI06> =
:-)

Now i have the idea to use a guide rail (attachment!) as an electrode =
for a earth electrode antenna! There is a perfect road which is not much =
frequented and where no way is crossing so i could temporary install a =
long wire on the ground between two of these guide rails. I would assume =
they provide a good grounding. They are located on a relatively high =
hill/mountain with stony ground. The mountain is very steep there and in =
some distance, 200m deeper, there is a brook..

With some luck the ground losses can be near 200 Ohm? Maybe rather 300 =
Ohm. I'm going to prepare things and plan to transmit for some time next =
weekend. If the ground loop actually acts like a loop, the bearing =
should be 135 deg, so it will be in a 45 deg angle towards my QTH where =
my grabber is listening in 55 km distance. That's quite a good distance =
for testing! I'd like to try LF and VLF, maybe ULF it all works well.

A BTW the wire length will be 860 m! However there are two guide rails =
in a shorther distance, about 450 m. I will try the shorter length =
first, to get an impression of the loss resistance and to see if =
something is visible at all :-)

73, Stefan


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lang=3DEN-US link=3Dblue vlink=3Dpurple><div class=3DWordSection1><p =
class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'>Stefan,<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'><o:p>&nbsp;</o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'>Congratulations on new =E2=80=9CTX earth antenna league=E2=80=9D =
far-field records including 5170 Hz. Quite exciting, and impressive =
resistance values.<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'><o:p>&nbsp;</o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'>73,<o:p></o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'><o:p>&nbsp;</o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'>Jim AA5BW =C2=A0=C2=A0<o:p></o:p></span></p><p =
class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'><o:p>&nbsp;</o:p></span></p><div><div =
style=3D'border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in =
0in 0in'><p class=3DMsoNormal><b><span =
style=3D'font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowt=
ext'>From:</span></b><span =
style=3D'font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowt=
ext'> owner-rsgb_lf_group@blacksheep.org =
[mailto:owner-rsgb_lf_group@blacksheep.org] <b>On Behalf Of =
</b>DK7FC<br><b>Sent:</b> Saturday, July 28, 2018 6:50 AM<br><b>To:</b> =
rsgb_lf_group@blacksheep.org<br><b>Subject:</b> Re: VLF: Earth antenna =
transmissions on a guide rail?!?? NOW on the =
air...<o:p></o:p></span></p></div></div><p =
class=3DMsoNormal><o:p>&nbsp;</o:p></p><p class=3DMsoNormal>Update: =
Since 10:13 UTC i'm TXing on 5170 Hz. The antenna current is 556 mA and =
the phase looks a bit less inductive but still inductive. Despite beeing =
in the center of the Pf=C3=A4lzer Wald, i have mobile internet access =
and so i reached my Linux PC recording the VLF stream (both loop =
antennas). Using vlfrx-tools i managed to produce a spectrum peak of 17 =
dB SNR after just 30 minutes!!!! (More later) So it is possible with =
this ground loop TX antenna to transmit on 5170 Hz and beeing detected =
in about&nbsp; 55 km distance! :-)&nbsp; These are two new records for =
the TX earth antenna league :-)<br>I'm going to continue transmitting on =
5170.000 Hz until 11:13 UTC, then i'll do QSY to 2970.005 Hz which =
simply means i change the frequency in SpecLabs signal generator driving =
my PA! :-)<br><br>73, Stefan<br><br>Am 28.07.2018 11:43, schrieb DK7FC: =
<o:p></o:p></p><p class=3DMsoNormal>Hi VLF,<br><br>I'm sitting in my car =
while writing this email. I'm in JN39WI96GX and i transmit on 8270.000 =
Hz with a GPS locked signal generator into an about 450 m long earth =
antenna using two guide rails as the earth electrodes on both ends. On =
each end there are 16 (18) massive T-T poles holding the guide rail, =
providing a super good earth coupling. I measured that they are =
connected to each other. <br>The transmitter is on the air since 9:08 =
UTC running 550 mA with just 75 W DC inout power into my hand warm lossy =
linear mode VLF PA! <br><br>I'm amazed about the low losses! At DC i got =
447 mA at 50.9 V. The wire is 0.4 mm diameter so it has 63 Ohm. That =
means the ground loss is just 50 Ohm !!!! Amazing! And i have no efforts =
to build up a ground connection here, i just need to connect the wire. =
Since the wire losses are higher than the ground losses, i can get maybe =
2 dB more signal when buying some better wire. I already found a source =
that offers 0.75 mm^2 100 m loudspeaker cable (i.e. 200m wire)for just =
13 EUR....<br><br>BTW i even have an ugly old scope here which is =
battery powered. I can see that the phase of voltage and current is =
slightly inductive, maybe 30 deg or so. So i could series resonate the =
antenna with some C. This is for the next experiment...<br><br>The =
signal becomes visible on my grabber now, in 424 uHz and also some =
bright pixels in the 3.8 mHz window.<br><br>I'm going to stop the =
carrier at 10:08 UTC, after 1 hour. Then i'll continue on 5.17 kHz! =
<br>BTW the antenna , if it works like a real loop, is beaming directly =
to Paul Nicholson ;-)<br><br>73, Stefan<br><br><br><br><br>Am 26.07.2018 =
17:19, schrieb DK7FC: <o:p></o:p></p><p class=3DMsoNormal>...i just =
searched in the old emails and also on G3XBM's blog and found this =
entry: <a =
href=3D"https://g3xbm-qrp.blogspot.com/2010/09/vlf-dx-transmission-with-e=
arth.html">https://g3xbm-qrp.blogspot.com/2010/09/vlf-dx-transmission-wit=
h-earth.html</a><br>So that is the best distance on a transmit earth =
antenna (or ground loop) so far, at VLF, by amateurs. <br>I had a much =
lower earth resistance in mind but actually i just got 0.53 A at 250 W =
RF power, so the losses were rather 890 Ohm!<br>Will it be possible to =
make 55 km distance at 8.27 kHz, maybe in a lower bandwidth like 424 =
uHz, with power levels in the range of 50 W only?<br><br>73, =
Stefan<br><br>Am 22.07.2018 20:28, schrieb DK7FC: <o:p></o:p></p><p =
class=3DMsoNormal>Hi all, <br><br>During the weekend i am in the =
Pf=C3=A4lzer Wald again which is such a nice place to be! I already =
installed a fixed E field antenna for VLF/ULF reception in <a =
href=3D"http://k7fry.com/grid/?qth=3DJN39XI06">JN39XI06 =
</a>:-)<br><br>Now i have the idea to use a guide rail (attachment!) as =
an electrode for a earth electrode antenna! There is a perfect road =
which is not much frequented and where no way is crossing so i could =
temporary install a long wire on the ground between two of these guide =
rails. I would assume they provide a good grounding. They are located on =
a relatively high hill/mountain with stony ground. The mountain is very =
steep there and in some distance, 200m deeper, there is a =
brook..<br><br>With some luck the ground losses can be near 200 Ohm? =
Maybe rather 300 Ohm. I'm going to prepare things and plan to transmit =
for some time next weekend. If the ground loop actually acts like a =
loop, the bearing should be 135 deg, so it will be in a 45 deg angle =
towards my QTH where my grabber is listening in 55 km distance. That's =
quite a good distance for testing! I'd like to try LF and VLF, maybe ULF =
it all works well.<br><br>A BTW the wire length will be 860 m! However =
there are two guide rails in a shorther distance, about 450 m. I will =
try the shorter length first, to get an impression of the loss =
resistance and to see if something is visible at all :-)<br><br>73, =
Stefan<o:p></o:p></p></div></body></html>
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