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 x447wWsm018715 for ; Sat, 4 May 2019 09:58:33 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1hMpHp-0000my-8w for rs_out_1@blacksheep.org; Sat, 04 May 2019 08:40:45 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1hMpEW-0000mk-JZ for rsgb_lf_group@blacksheep.org; Sat, 04 May 2019 08:37:21 +0100 Received: from mx-04.asamnet.net ([62.245.182.76]) by relay1.thorcom.net with esmtps (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92) (envelope-from ) id 1hMpEU-0007bd-Nh for rsgb_lf_group@blacksheep.org; Sat, 04 May 2019 08:37:19 +0100 Received: from xmail.asamnet.net ([62.245.182.71]) by mx-04.asamnet.net stage1 with esmtps (Exim MailCleaner) id 1hMpCc-0000zW-Fu for from ; Sat, 04 May 2019 09:36:51 +0200 Received: from AdminPC (188.194.89.251) by xmail.asamnet.net (Axigen) with (ECDHE-RSA-AES128-GCM-SHA256 encrypted) ESMTPSA id 33E046; Sat, 4 May 2019 09:35:22 +0200 From: "Bernhard Wiesgickl" To: Subject: LF: Experiences with a symmetrical vertical antenna on ELF/VLF Date: Sat, 4 May 2019 09:35:18 +0200 Message-ID: <000e01d5024b$ec8416e0$c58c44a0$@asamnet.net> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000F_01D5025C.B00D5C10" X-Mailer: Microsoft Outlook 14.0 Thread-Index: AdUCS5lZ8/4nDetvQ+6juR+6kP0Qeg== Content-Language: de X-AxigenVirus-Level: 1 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: Hello VLF-/ELF-enthusiasts, I built a slightly modified symmetrical vertical antenna which is described from IW5BHY in http://www.vlf.it/immagine/minimal_E.html and I want let you to k [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 46d617994b9fba079dc3ad7182acba54 X-SA-Exim-Scanned: No; SA Timed out after 180 secs 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 This is a multipart message in MIME format. ------=_NextPart_000_000F_01D5025C.B00D5C10 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hello VLF-/ELF-enthusiasts, I built a slightly modified symmetrical vertical antenna which is described from IW5BHY in http://www.vlf.it/immagine/minimal_E.html and I want let you to know my experience with this antenna. First we installed this antenna at DL0AO. DL0AO is in a rural area in the wood. But the result was very disappointing! Already light wind increased the noise by 20 to 30 dB from 5 Hz to 2 kHz and on frequencies around 20 kHz several phantom signals were present when wind was blowing. Even during quiet periods no Schumann-resonances were visible and ZEVS was very weak and the S/N of the submarine-TXs around 20 kHz was comparable to our ground-loops or E-field antenna (again: when there was no wind). Presumably the surrounding high trees in 20 to 100 m distance and (or?) the wire-mesh fence with a very rusty barbed wire on top, only 20 m away from the antenna, was the reason. So I installed the antenna in my garden at home. With my small T-Marconi-antenna the noise level is quite high at home and I did not expect too much advantage with the symmetrical vertical antenna. But surprise, surprise! The S/N of the submarine-TXs is up to 10 dB better compared to the small marconi, ZEVS is good visible, the Schumann-Resonances are clearly visible (both not visible with the marconi-antenna) and a weak test-signal on 8.270 kHz from DF6NM was 15 db above the noise. Compared to our antennas at DL0AO the S/N of the submarine-TXs are only 3 to 5 dB lower, ZEVS and Schumann-resonances are comparable between home and DL0AO. Summary: The symmetrical vertical antenna is much more sensitive to environmental effects than a vertical working against ground. But when you use an antenna working not against ground in areas where the ground is noisy (in my case urban area, single family houses, no industry, no electrified train) satisfactorily reception of ELF- and VLF-signals is possible with a symmetrical vertical dipole. Bernd, DF9RB (one sysop of the grabbers at DL0AO) ------=_NextPart_000_000F_01D5025C.B00D5C10 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Hello VLF-/ELF-enthusiasts,

 

I built a slightly modified = symmetrical vertical antenna which is described from IW5BHY in http://www.vlf.it/immagine/minimal_E.html= and I want let you to know

my experience with this = antenna.

First we installed this antenna at DL0AO. DL0AO is in a = rural area in the wood. But the result was very disappointing! Already = light wind increased the noise by 20 to 30 dB from 5 Hz = to

2 kHz = and on frequencies around 20 kHz several phantom signals were present = when wind was blowing. Even during quiet periods no Schumann-resonances = were visible and

ZEVS was very weak and the S/N of the submarine-TXs around = 20 kHz  was comparable to our ground-loops or E-field antenna = (again: when there was no wind).

Presumably the surrounding high = trees in 20 to 100 m distance and (or?) the wire-mesh fence with a very = rusty barbed wire on top, only 20 m away from the =

antenna, = was the reason.

So I installed the antenna in my garden at home. With my = small T-Marconi-antenna  the noise level is quite high at home and = I did not expect too much advantage

with the symmetrical vertical = antenna. But surprise, surprise! The S/N of the submarine-TXs is up to = 10 dB better compared to the small marconi, ZEVS is good = visible,

the Schumann-Resonances are clearly visible (both not = visible with the marconi-antenna) and a weak test-signal on 8.270 kHz = from DF6NM was 15 db above the noise.

Compared to our antennas at DL0AO = the S/N of the submarine-TXs are only 3 to 5 dB lower, ZEVS and = Schumann-resonances are comparable between home and = DL0AO.

 

Summary:

The symmetrical = vertical antenna is much more sensitive to environmental effects than a = vertical working against ground.

But = when you use an antenna working not against ground in areas where the = ground is noisy (in my case urban area, single family houses, no = industry, no electrified train)

satisfactorily reception of ELF- = and VLF-signals is possible with a symmetrical vertical = dipole.

 

 

Bernd, DF9RB (one sysop of the grabbers at = DL0AO)

 

 

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