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 x1EMnWiF023118 for ; Thu, 14 Feb 2019 23:49:34 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1guPkK-0005AT-Mz for rs_out_1@blacksheep.org; Thu, 14 Feb 2019 22:44:44 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1guPk7-0005AG-Az for rsgb_lf_group@blacksheep.org; Thu, 14 Feb 2019 22:44:31 +0000 Received: from rgout0107.bt.lon5.cpcloud.co.uk ([65.20.0.127] helo=rgout01.bt.lon5.cpcloud.co.uk) by relay1.thorcom.net with esmtp (Exim 4.91) (envelope-from ) id 1guPk4-00049u-R4 for rsgb_lf_group@blacksheep.org; Thu, 14 Feb 2019 22:44:30 +0000 X-OWM-Source-IP: 86.185.188.234 (GB) X-OWM-Env-Sender: alan.melia@btinternet.com X-RazorGate-Vade-Classification: clean X-RazorGate-Vade-Verdict: clean 0 X-VadeSecure-score: verdict=clean score=0/300, class=clean X-SNCR-VADESECURE: CLEAN X-RazorGate-Vade-Verdict: clean 0 X-RazorGate-Vade-Classification: clean X-RazorGate-Vade: gggruggvucftvghtrhhoucdtuddrgedtledruddthedgudeihecutefuodetggdotefrodftvfcurfhrohhfihhlvgemuceutffkvffkuffjvffgnffgvefqofdpqfgfvfenuceurghilhhouhhtmecufedttdenucenucfjughrpefkhffvfhfuffggtgfrigfopffqsegrtdejpedutddunecuhfhrohhmpedftehlrghnucfovghlihgrfdcuoegrlhgrnhdrmhgvlhhirgessghtihhnthgvrhhnvghtrdgtohhmqeenucffohhmrghinhepshgtrghlvggslhgrshhtvghrrdgtohhmnecukfhppeekiedrudekhedrudekkedrvdefgeenucfrrghrrghmpehhvghlohepghhnrghtpdhinhgvthepkeeirddukeehrddukeekrddvfeegpdhmrghilhhfrhhomhepoegrlhgrnhdrmhgvlhhirgessghtihhnthgvrhhnvghtrdgtohhmqedprhgtphhtthhopeeorhhsghgspghlfhgpghhrohhuphessghlrggtkhhshhgvvghprdhorhhgqeenucevlhhushhtvghrufhiiigvpedt Received: from gnat (86.185.188.234) by rgout01.bt.lon5.cpcloud.co.uk (9.0.019.26-1) (authenticated as alan.melia@btinternet.com) id 5B321EA0150C8BD2 for rsgb_lf_group@blacksheep.org; Thu, 14 Feb 2019 22:44:28 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=btcpcloud; t=1550184268; bh=n3Rtpb1uRFA+/J27yVhlbc7jPoGcsbViNqHsSUNTtnE=; h=Message-ID:From:To:References:Subject:Date:MIME-Version:X-Mailer; b=GCBRDc8xQgHJrOX7ZFkNA3mg4hrTRuXamy6lz1NsvYtrQC2AJKUmHilPJIFD9DSt9gYol0r++fieVbFbPAqKitoLzp7maYSnbS9zEM36HCT3Z0CsP5i4UovtxWj1TcHYaI8+oj+YJw/LwMwbc4MAD+P9ImXAVj18nS6dvmKk/ts= Message-ID: From: "Alan Melia" To: References: <028901d4c4a6$f890ee50$e9b2caf0$@comcast.net> Date: Thu, 14 Feb 2019 22:43:15 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 Disposition-Notification-To: "Alan Melia" X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 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 the administrator of that system for details. Content preview: What is worse Jim is there is no credible scientific study published on whether the work and how. For those with the ''right'' kinf of mind it can be an amusing exercise to take this up with the maker [...] 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 [65.20.0.127 listed in list.dnswl.org] -0.0 RCVD_IN_MSPIKE_H2 RBL: Average reputation (+2) [65.20.0.127 listed in wl.mailspike.net] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 070d9ab39265047b7fb462cd62854f10 Subject: LF: Re: QRM - Other Content-Type: multipart/alternative; boundary="----=_NextPart_000_001E_01D4C4B6.AC0E7E70" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.8 required=5.0 tests=FORGED_MUA_OUTLOOK,HTML_50_60, HTML_MESSAGE 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 This is a multi-part message in MIME format. ------=_NextPart_000_001E_01D4C4B6.AC0E7E70 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable What is worse Jim is there is no credible scientific study published on = whether the work and how. For those with the ''right'' kinf of mind it = can be an amusing exercise to take this up with the makers. Oh on the = ones we looked at the chip (filed top) was a 555 or 556 timer. One maker = quoted a University report. When chased it was not done by a science = faculty and was never published. It gets boring when the best = justification is '' We've sold thousands so it must work'' Alan G3NYK=20 ----- Original Message -----=20 From: hvanesce@comcast.net=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, February 14, 2019 8:50 PM Subject: LF: QRM - Other =20 This popular item doesn't seem particularly friendly for ULF-VLF; 40 = to 76 turns wrapped around the home's water main pipe, ~ 2 amps out, = sweeping 1 kHz to 20 kHz every 50 milliseconds. https://www.scaleblaster.com/wp-content/uploads/docs/spec-max.pdf = https://www.scaleblaster.com/wp-content/uploads/docs/installation-max.pdf= which would seem to give roughly 40 fT at 100m at for the specified 70 = turns on 4 cm water main, not counting eddy currents in the copper pipe. Not sure how current varies* with frequency in these devices, or how = rectangular the current waveform is. * (guessing current varies as 1/f, which would mean roughly 30 fT at = 50m at 10 kHz) =20 A commercial unit provides 10A-40A into a 200uH coil around the water = main (less current into the nominal 1 mH coil): = https://www.scaleblaster.com/wp-content/uploads/2016/08/SB-4000-clm276.pd= f = https://www.scaleblaster.com/wp-content/uploads/2016/07/Sb1200-SB4000-Ins= tall-Operations-Manual.pdf which would seem to give roughly 10 fT at 1 km for the specified 7 = turns on 106 cm water main. =20 - Jim AA5BW =20 ------=_NextPart_000_001E_01D4C4B6.AC0E7E70 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
What is worse Jim is there is no = credible=20 scientific study published on whether the work and how. For those with=20 the ''right'' kinf of mind it can be an amusing exercise to take = this up=20 with the makers. Oh on the ones we looked at the chip (filed top) was a = 555 or=20 556 timer. One maker quoted a University report. When chased it was not = done by=20 a science faculty and was never published. It gets boring when the best=20  justification is '' We've sold thousands so it must=20 work''
 
Alan
G3NYK 
----- Original Message -----
From:=20 hvanesce@comcast.net
Sent: Thursday, February 14, = 2019 8:50=20 PM
Subject: LF: QRM - Other

 

This popular item doesn=92t seem particularly = friendly for=20 ULF-VLF; 40 to 76 turns wrapped around the home=92s water main pipe, ~ = 2 amps=20 out, sweeping 1 kHz to 20 kHz every 50 milliseconds.

https://www.scaleblaster.com/wp-content/uploads/docs/spec-max.pdf

https://www.scaleblaster.com/wp-content/uploads/docs/installati= on-max.pdf

which would seem to give roughly 40 fT at 100m at = for the=20 specified 70 turns on 4 cm water main, not counting eddy currents in = the=20 copper pipe.

Not sure how current varies* with frequency in = these=20 devices, or how rectangular the current waveform is.

  * (guessing current varies as 1/f, which = would mean=20 roughly 30 fT at 50m at 10 kHz)

 

A commercial unit provides 10A-40A into a 200uH = coil around=20 the water main (less current into the nominal 1 mH = coil):

https://www.scaleblaster.com/wp-content/uploads/2016/08/SB-400= 0-clm276.pdf

https://www.scaleblaster.com/wp-conte= nt/uploads/2016/07/Sb1200-SB4000-Install-Operations-Manual.pdf

which would seem to give roughly 10 fT at 1 km = for the=20 specified 7 turns on 106 cm water main.

 

- Jim AA5BW=20  

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