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[195.171.43.25]) by mx.google.com with ESMTP id u4si2512627wjq.117.2014.03.05.15.51.38 for ; Wed, 05 Mar 2014 15:51:39 -0800 (PST) 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; Authentication-Results: mx.google.com; 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) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass header.i=@mx.aol.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1WLKv4-0005Tl-FK for rs_out_1@blacksheep.org; Wed, 05 Mar 2014 23:08:10 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1WLKv3-0005Tc-WC for rsgb_lf_group@blacksheep.org; Wed, 05 Mar 2014 23:08:09 +0000 Received: from omr-d03.mx.aol.com ([205.188.109.200]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.82) (envelope-from ) id 1WLKv2-000081-2L for rsgb_lf_group@blacksheep.org; Wed, 05 Mar 2014 23:08:08 +0000 Received: from mtaout-mbc01.mx.aol.com (mtaout-mbc01.mx.aol.com [172.26.221.141]) by omr-d03.mx.aol.com (Outbound Mail Relay) with ESMTP id BCDA4701E0481 for ; Wed, 5 Mar 2014 18:08:05 -0500 (EST) Received: from White (95-91-237-52-dynip.superkabel.de [95.91.237.52]) by mtaout-mbc01.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 3360B380000B3 for ; Wed, 5 Mar 2014 18:08:05 -0500 (EST) Message-ID: From: "Markus Vester" To: References: <5316EA0B.4020001@abelian.org> <004001cf3870$27cb9620$6401a8c0@JAYDELL> <53173FCD.9010808@abelian.org> <5317A9C5.2050303@tele2.se> Date: Thu, 6 Mar 2014 00:08:04 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1394060885; bh=NKl3d0mnaGDu/LseVo9IvKmYXlWmg28gd8HM+o+R4uE=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=yAAgLi6+Z46oxIna0qYsPJLJD+zQq9+63/KMmC1S6fHxDEaxXXgX6nUFYuDUhYdYF z+3qCEvpw559FlHwpweqj+X6fB3AGbsq2z+Z9mbXKdlltjCMSUZAw/S7KcCE9mmSsc Z8cx3qUIdS/ME21XzwPoZfCpl/XBdk0Y7B0mEnw4= x-aol-sid: 3039ac1add8d5317ae5535d0 X-AOL-IP: 95.91.237.52 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Johan, unfortunately the difference between "upper and lower" VLF will be much larger than that. Operating a small electric antenna at the same voltage limit, radiated power scales with the fourth power of frequency. A current limited TX loop would scale the same way. Thus going from 29.5 to 8.27 kHz will reduce the fieldstrength by 22 dB. In addition, background noise from distant static tends to peak around 9 kHz, which may easily make another 10 dB SNR deterioration. [...] 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 [205.188.109.200 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 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: 34d483c57c7a6bf26c25db3c8765d5fc Subject: Re: LF: Re: VLF 29501, signal? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0039_01CF38D0.24F73ED0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,HTML_MESSAGE, MISSING_OUTLOOK_NAME 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 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0039_01CF38D0.24F73ED0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Johan, unfortunately the difference between "upper and lower" VLF will be much = larger than that. Operating a small electric antenna at the same voltage = limit, radiated power scales with the fourth power of frequency. A = current limited TX loop would scale the same way. Thus going from 29.5 = to 8.27 kHz will reduce the fieldstrength by 22 dB. In addition, = background noise from distant static tends to peak around 9 kHz, which = may easily make another 10 dB SNR deterioration. But well, challenges are there for us to meet them ;-) Best 73, Markus From: Johan Bodin=20 Sent: Wednesday, March 05, 2014 11:48 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Re: VLF 29501, signal? Yes, an impressive achievement indeed, congratulations to all involved! Wow is the word! The 24dB S/N ratio on Dex' signal exceeded all my expectations! 24 dB S/N is "armchair copy". It would be interesting to actually listen to a spectrally shifted and time compressed version of the signal. Can you do that on your Linux box Paul? Not for scientific purposes but for pure sheer joy :-) Given 24dB S/N headroom at 29.5kHz, sub 9 kHz TA is probably not too far away! The TX antenna would be no more than ~10dB down compared to 30k. 73 Johan SM6LKM ... ------=_NextPart_000_0039_01CF38D0.24F73ED0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Johan,
 
unfortunately the difference between = "upper and=20 lower" VLF will be much larger than that. Operating a small electric=20 antenna at the same voltage limit, radiated power scales with = the=20 fourth power of frequency. A current limited TX loop would scale the = same way.=20 Thus going from 29.5 to 8.27 kHz will reduce the fieldstrength = by 22=20 dB. In addition, background noise from distant static tends=20 to peak around 9=20 kHz, which may easily make another 10 dB = SNR=20 deterioration.
 
But well, challenges = are there=20 for us to meet them ;-)
 
Best = 73,
Markus

From: Johan Bodin
Sent: Wednesday, March 05, 2014 11:48 PM
To: rsgb_lf_group@blacksheep.org= =20
Subject: Re: LF: Re: VLF 29501, signal?

Yes, an = impressive=20 achievement indeed, congratulations to all involved!

Wow is the = word! The=20 24dB S/N ratio on Dex' signal exceeded all my
expectations! 24 dB S/N = is=20 "armchair copy". It would be interesting to
actually listen to a = spectrally=20 shifted and time compressed version of
the signal. Can you do that on = your=20 Linux box Paul? Not for scientific
purposes but for pure sheer joy=20 :-)

Given 24dB S/N headroom at 29.5kHz, sub 9 kHz TA is probably = not too=20 far
away! The TX antenna would be no more than ~10dB down compared to = 30k.

73
Johan SM6LKM

... ------=_NextPart_000_0039_01CF38D0.24F73ED0--