Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w6ABFVK0029829 for ; Tue, 10 Jul 2018 13:15:32 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1fcqXh-0001NA-0u for rs_out_1@blacksheep.org; Tue, 10 Jul 2018 12:10:49 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1fcqXg-0001N1-LK for rsgb_lf_group@blacksheep.org; Tue, 10 Jul 2018 12:10:48 +0100 Received: from mail-oi0-x232.google.com ([2607:f8b0:4003:c06::232]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1fcqXd-0000xM-Gd for rsgb_lf_group@blacksheep.org; Tue, 10 Jul 2018 12:10:47 +0100 Received: by mail-oi0-x232.google.com with SMTP id n84-v6so41799784oib.9 for ; Tue, 10 Jul 2018 04:10:45 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=+XI/w5dmMl6Od3ap9SDBptskpoNvRzAJxvxY5t2UYEo=; b=naoydxND8DItfnLxhn0CnupF71hG5oGAdek2dkQKlXqJJ2AZpY7W8f6TRXmVxh0SD2 EO6YsPTNStuR3qaX47VIHfPHbshjJrRyMBlI7ifZZZgzYRHa8H+r5RNVYcvYDRxAKlrS nb13R1CwrNXjSXR8BSBHzW1r4bxdroJ/FFoZkI5dbbwR9TbfnR/q6PLfgzqihlL5miID 17qb/RWXlKszYcyxBJcIZhJcwzGgMnTbO9/Bv1EdKVn9cJeoDs/KDCVMcR4v+k9bJYro dYtqPBKx99q7UB3q+IJtBhkMf1Pxi8geZHzrLtjfaCFZgR4q/1MbTuxaSSi5N2CwpqUi 8Hsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=+XI/w5dmMl6Od3ap9SDBptskpoNvRzAJxvxY5t2UYEo=; b=RmDlv2fXiFh5ns0BN5mDju0JKQNVVrtWOZ6rehll0oygaiEOOPz7TD5ASdFXJFIxiM inIHoLVVHKG0x5lj723ZfmLuazdcWCYkujY1bovY9hMcyCjfkAZ5Bp3sI/oTfI5XpYqA h3Q/YYoFZi5vJBvlnA0TmRiilgFUI4b4gEYgYf4XJObL5bsz/IxxCeiL4DARnoRFqYFU LI8bcyEX6VEu7MeR2fyEkGICoduoWZHOZ5R98nzXnWS1vcWEoxyF0JHYaBuFbtPGfbZl 0JCa3mbCybcoDduO0LPYY0JaSJEfEswLQd3OyXTMaqbvz8ZrPHr5ujtqnMEfxidEpvmb MQ2w== X-Gm-Message-State: APt69E2Yz1dZIqkUjX8lzwWjwQUliDtvJwUFG31gRDFtEkHy7f90P51x RQIj7XBc+zOoOZAXyl8f36K+UcvFsYlaQnMltkY= X-Google-Smtp-Source: AAOMgpdUAFWizVswb83PBR2G+02g9c5L9Sr9Ht+Y/6nbW1skqg9WLkCcqY+EA6LwM+TsoxoU6ezV8/ih4l+5PhfN7DE= X-Received: by 2002:aca:42:: with SMTP id 63-v6mr24856596oia.154.1531221041282; Tue, 10 Jul 2018 04:10:41 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a9d:4884:0:0:0:0:0 with HTTP; Tue, 10 Jul 2018 04:10:40 -0700 (PDT) In-Reply-To: <5B3F2536.3040408@posteo.de> References: <5B38A763.17452.850587@roelof.ndb.demon.nl> <5B3BB75F.9030305@posteo.de> <000601d41303$c6719870$5354c950$@go2.pl> <5B3BEDA5.9050902@posteo.de> <6DB8451D7F3D3947A5918808A59621EA08524F3A@servigilant.vigilant.local> <5B3F2536.3040408@posteo.de> From: Roger Lapthorn Date: Tue, 10 Jul 2018 12:10:40 +0100 Message-ID: To: "rsgb_lf_group@blacksheep.org" X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: Dear All, As I have been away for a few days let me say a few words. - Yes, I agree that a "decent" antenna and ground system will outperform an "earth antenna". - Certainly at 472kHz I have been amazed how well an earth antenna works. In the autumn and winter seasons I reach over 1000km to Norway quite regularly with 5mW ERP using mine with WSPR. - My "baseline" is only about 12m, so not long at all. - The earth connections are about 1m rods driven into the soil. - Interconnecting wire is multi-strand hook-up wire. I think it is 32 x 0.2mm. - At the old QTH it was a good match to the transverter at 50 ohms. At the new QTH it is better with a 3C90 step-up transformer. This implies a higher resistance at the "new" QTH. We have now been here almost 5 years! - In my view the "earth antenna" works as a loop at 472kHz and 137kHz. I have *not* had good results at higher frequencies. - As a "compromise" antenna it is worth trying. - With low conductivity soil or rock the loop size would be bigger. - Magic? No! - Radiated VLF? No idea. I suspect it would work as the skin depth would be better as you go lower in frequency. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [2607:f8b0:4003:c06:0:0:0:232 listed in] [list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (rogerlapthorn[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 1273381c241b4bc851b7e848e0897dc9 Subject: Re: LF: RE: Summer games / EARTH ANTENNAS Content-Type: multipart/alternative; boundary="0000000000003d05d30570a32e95" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=HTML_MESSAGE, TO_ADDRESS_EQ_REAL autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false --0000000000003d05d30570a32e95 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear All, As I have been away for a few days let me say a few words. - Yes, I agree that a "decent" antenna and ground system will outperform an "earth antenna". - Certainly at 472kHz I have been amazed how well an earth antenna works. In the autumn and winter seasons I reach over 1000km to Norway qu= ite regularly with 5mW ERP using mine with WSPR. - My "baseline" is only about 12m, so not long at all. - The earth connections are about 1m rods driven into the soil. - Interconnecting wire is multi-strand hook-up wire. I think it is 32 x 0.2mm. - At the old QTH it was a good match to the transverter at 50 ohms. At the new QTH it is better with a 3C90 step-up transformer. This implies a higher resistance at the "new" QTH. We have now been here almost 5 years= ! - In my view the "earth antenna" works as a loop at 472kHz and 137kHz. I have *not* had good results at higher frequencies. - As a "compromise" antenna it is worth trying. - With low conductivity soil or rock the loop size would be bigger. - Magic? No! - Radiated VLF? No idea. I suspect it would work as the skin depth would be better as you go lower in frequency. Let us hope this input is useful. *Never* say you don't have space for a 472kHz antenna! 73s Roger G3XBM On 6 July 2018 at 09:15, DK7FC wrote: > > > Am 04.07.2018 18:51, schrieb VIGILANT Luis Fern=C3=A1ndez: > > Mmmm. Kite antennas are for summer ;-) > > > What? Ehm, no. They are for winter! :-) > See: http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/300m% > 20VLF%20kite%20vertical.jpg > > Helium is much to expensive and you can use the baloon just one time, the= n > you have to release the gas again. This is not practical! And if there is > strong wind, the baloon is not very stable, expect you make it much large= r > than necessary, so there is a strong force on the wire. > > A kite however can stay stable in the air for hours! Once i kept it in th= e > air (including a 100m wire connected) for > 24 hours. Everyone (even if > retired!) can buy a kite and some string and rise it somewhere :-) > > 73, Stefan > --0000000000003d05d30570a32e95 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear All,

As I have been awa= y for a few days let me say a few words.
  • Yes, I agree that= a "decent" antenna and ground system will outperform an "ea= rth antenna".
  • Certainly at 472kHz I have been amazed how well = an earth antenna works. In the autumn and winter seasons I reach over 1000k= m to Norway quite regularly with 5mW ERP using mine with WSPR.
  • My &= quot;baseline" is only about 12m, so not long at all.=C2=A0
  • Th= e earth connections are about 1m rods driven into the soil.
  • Interco= nnecting wire is multi-strand hook-up wire. I think it is 32 x 0.2mm.
    • <= li>At the old QTH it was a good match to the transverter at 50 ohms. At the= new QTH it is better with a 3C90 step-up transformer. This implies a highe= r resistance at the "new" QTH. We have now been here almost 5 yea= rs!
  • In my view the "earth antenna" works as a loop at= 472kHz and 137kHz. I have not had good results at higher frequencie= s.
  • As a "compromise" antenna it is worth trying.
  • = With low conductivity soil or rock the loop size would be bigger.
    • <= li>Magic? No!
  • Radiated VLF? No idea. I suspect it would work as the= skin depth would be better as you go lower in frequency.
Let us hope this input is useful. Never say you don't have spac= e for a 472kHz antenna!

73s
Roger G3XBM<= /div>


On 6 July 2018 at 09:15, DK7FC <selberdenken@posteo.de&g= t; wrote:
=20 =20


Am 04.07.2018 18:51, schrieb VIGILANT Luis Fern=C3=A1ndez:
=20 =20 =20

Mmmm. Kite antennas are for summer ;-)


 What? Ehm, no. They are for winter! :-)
See: http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/300= m%20VLF%20kite%20vertical.jpg

Helium is much to expensive and you can use the baloon just one time, then you have to release the gas again. This is not practical! And if there is strong wind, the baloon is not very stable, expect you make it much larger than necessary, so there is a strong force on the wire.

A kite however can stay stable in the air for hours! Once i kept it in the air (including a 100m wire connected) for > 24 hours. Everyone (even if retired!) can buy a kite and some string and rise it somewhere :-)

73, Stefan

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