Delivered-To: daveyxm@virginmedia.com Received: by 10.50.142.105 with SMTP id rv9csp208469igb; Tue, 24 Jun 2014 04:27:17 -0700 (PDT) X-Received: by 10.180.90.242 with SMTP id bz18mr33956865wib.12.1403609236626; Tue, 24 Jun 2014 04:27:16 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id y1si21119127wij.95.2014.06.24.04.27.15 for ; Tue, 24 Jun 2014 04:27:16 -0700 (PDT) Received-SPF: none (google.com: owner-rsgb_lf_group@blacksheep.org does not designate permitted sender hosts) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: owner-rsgb_lf_group@blacksheep.org does not designate permitted sender hosts) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass header.i=@mx.aol.com; dmarc=pass (p=REJECT dis=NONE) header.from=aol.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1WzOOO-0006oc-Ku for rs_out_1@blacksheep.org; Tue, 24 Jun 2014 11:56:00 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1WzOOO-0006oT-8U for rsgb_lf_group@blacksheep.org; Tue, 24 Jun 2014 11:56:00 +0100 Received: from omr-m09.mx.aol.com ([64.12.143.82]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.82) (envelope-from ) id 1WzOOJ-0001rD-2t for rsgb_lf_group@blacksheep.org; Tue, 24 Jun 2014 11:55:59 +0100 Received: from mtaomg-mae02.mx.aol.com (mtaomg-mae02.mx.aol.com [172.26.254.144]) by omr-m09.mx.aol.com (Outbound Mail Relay) with ESMTP id 80E2C7027A248 for ; Tue, 24 Jun 2014 06:55:52 -0400 (EDT) Received: from core-afa03a.mail.aol.com (core-afa03.mail.aol.com [172.27.24.3]) by mtaomg-mae02.mx.aol.com (OMAG/Core Interface) with ESMTP id 3DFBC38000083 for ; Tue, 24 Jun 2014 06:55:52 -0400 (EDT) References: <53A8AE53.3060504@gmail.com> To: rsgb_lf_group@blacksheep.org In-Reply-To: <53A8AE53.3060504@gmail.com> X-MB-Message-Source: WebUI MIME-Version: 1.0 From: Markus Vester X-MB-Message-Type: User X-Mailer: AOL Webmail BASIC Received: from 194.138.39.59 by webmail-d249.sysops.aol.com (205.188.17.50) with HTTP (WebMailUI); Tue, 24 Jun 2014 06:55:51 -0400 Message-Id: <8D15DB1FF8A27AE-2018-717F@webmail-d249.sysops.aol.com> X-Originating-IP: [194.138.39.59] Date: Tue, 24 Jun 2014 06:55:51 -0400 (EDT) x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1403607352; bh=3QleacjMW9jmGcN99rioMJIgS5wQZWgAZqx4Z3hebt4=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=wiLgEDiOwXbNWZooiqtI+nq/ywzyfSHrJ2MXjN0J4G+lXzilP5LAn79xBWMgsgI85 iR14NV9/lTuJtOnXW9kbwW6qMmXanaWxIJsfT+0QYi0dWZfmSqd9sHfvUmKCNv8SM/ CF+j20vTa+oJEL/dO693LM2Z374eOX0LRPK5CxBQ= x-aol-sid: 3039ac1afe9053a95938403f X-Spam-Score: 2.7 (++) 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: Joe, good to read this!  Regarding the loading coil, I would agree with Stefan that a large multiturn air coil is the best option. A laminated iron core would suffer from excessive eddy current losses, and the effect of ferrites is limited by saturation and hysteresis losses.  My 1.3 henry coil consumed 2.3 km of 0.4 mm enameled wire, using 7 buckets with 480 turns on each: df6nm.bplaced.net/VLF/VLF_110304-06/coil_legospacers.jpg. The advantage is that due to magnetic coupling between layers, you will need less wire for a given inductance. And the inductance is adjustable across a wide range, using spacers. Disadvantages are the high electric field between layers limiting voltage capability, and less effective heat removal from the inner buckets. Stuffing the buckets too tightly into one another is surely not a good idea: df6nm.bplaced.net/VLF/pictures/arced_coil_140601.jpg  An nonresonant earth antenna across high resistivity rock could also radiate moderately well, avoiding coil making and high voltage issues altogether. But to compete with your vertical in terms of radiation resistance, it would need to be really long, on the order of a couple of miles. It will have magnetic loop directional pattern which may be a disadvantage.  For a transatlantic detection eg. by Paul Nicholson, a Rubidium or GPS locked signal source would be very beneficial. Using SpecLab with 1pps phase lock to eliminate soundcard output glitches has worked well for DJ8WX, PA1SDB, and myself.  Best of luck, Markus (DF6NM) [...] Content analysis details: (2.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [64.12.143.82 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record 1.7 URIBL_BLACK Contains an URL listed in the URIBL blacklist [URIs: bplaced.net] 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 1.0 FREEMAIL_REPLY From and body contain different freemails X-Scan-Signature: ed9dcf4545ec97a65e50af1597e81212 Subject: Re: LF: VLF in Canada Content-Type: multipart/alternative; boundary="--------MB_8D15DB1FFB761CE_2018_18405_webmail-d249.sysops.aol.com" 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=FORGED_AOL_TAGS,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. ----------MB_8D15DB1FFB761CE_2018_18405_webmail-d249.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Joe, good to read this!=20 =C2=A0 Regarding the loading coil, I would agree with Stefan that a large multitur= n air coil is the best option. A laminated iron core would suffer from exce= ssive eddy current losses, and the effect of ferrites is limited by saturat= ion and hysteresis losses. =C2=A0 My 1.3 henry coil consumed 2.3 km of 0.4 mm enameled wire, using 7 buckets = with 480 turns on each: df6nm.bplaced.net/VLF/VLF_110304-06/coil_legospacers.jpg. The advantage is that due to magnetic coupling between layers, you will nee= d less wire for a given inductance. And the inductance is adjustable across= a wide range, using spacers. Disadvantages are the high electric field bet= ween layers limiting voltage capability, and less effective heat removal fr= om the inner buckets. Stuffing the buckets too tightly into one another is = surely not a good idea: df6nm.bplaced.net/VLF/pictures/arced_coil_140601.jpg =C2=A0 An nonresonant earth antenna across high resistivity rock could also radiat= e moderately well, avoiding coil making and high voltage issues altogether.= But to compete with your vertical in terms of radiation resistance, it wou= ld need to be really long, on the order of a couple of miles. It will have = magnetic loop directional pattern which may be a disadvantage. =C2=A0 For a transatlantic detection eg. by Paul Nicholson, a Rubidium or GPS lock= ed signal source would be very beneficial. Using SpecLab with 1pps phase lo= ck to eliminate soundcard output glitches has worked well for DJ8WX, PA1SDB= , and myself. =C2=A0 Best of luck, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-----=20 Von: DK7FC <73dk7fc@googlemail.com> An: rsgb_lf_group <rsgb_lf_group@blacksheep.org> Verschickt: Di, 24 Jun 2014 12:48 am Betreff: Re: LF: VLF in Canada Hi Joe,=20 =20 Fine to hear that you're give it a try. Please, don't ask Industry =20 Canada if the 10mW is RF power of ERP!=20 =20 To get out a real signal on VLF, there is no alternative to a real large = =20 coil without ferrites! Think about the high voltages... But 100m of =20 antenna wire is a good start. I remember 550 mH for my 100m kite =20 antenna. For me it was 2000m of 0.4mm diameter wire :-) Nice work is =20 that. Takes long but is a funny game :-)=20 =20 73, GL, Stefan=20 =20 Am 23.06.2014 21:33, schrieb jcraig@mun.ca:=20 Dear Group,=20 I tried again to get an LOA for VLF. This time, the response from =20 Industry Canada was favourable: 10 mW 8.0-8.3 kHz. Yesterday, after a =20 few slight rf burns, and thanks to PA0RDT's miniwhip design and =20 DL4YHF's Spectrum Lab and advice, VLF sigs on 8.277 kHz were heard at =20 200m from the 100m wire aerial. This was a reception outside my back =20 yard! 10 watts from an 1970's keyboard amp (volume control set on 3) =20 were stepped up with an xfmr to a lossy 500 ohm tuning coil peaked =20 with a ferrite rod for maximum squeal at L=3D0.35 H.=20 Is it possible for someone who is not especially enthralled by winding=20 a mile of 0.7mm wire to use an iron core to make a VLF tuning coil?=20 73=20 Joe VO1NA=20 ----------MB_8D15DB1FFB761CE_2018_18405_webmail-d249.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8"
Joe, good = to read this!
 
Regarding = the loading coil, I would agree with Stefan that a large multiturn air coil= is the best option. A laminated iron core would suffer from excessive eddy= current losses, and the effect of ferrites is limited by saturation and hy= steresis losses.
 
My 1.3 hen= ry coil consumed 2.3 km of 0.4 mm enameled wire, using 7 buckets with 480 t= urns on each:
df6nm.bplaced.net/VLF/VLF_110304-06/coil_legospacers.jpg.
The advantage is that due to magnetic coupling between layers, you will nee= d less wire for a given inductance. And the inductance is adjustable across= a wide range, using spacers. Disadvantages are the high electric field bet= ween layers limiting voltage capability, and less effective heat removal fr= om the inner buckets. Stuffing the buckets too tightly into one another is = surely not a good idea:
df6nm.bplaced.net/VLF/pictures/arced_coil_140601.jpg
 
An nonreso= nant earth antenna across high resistivity rock could also radiate moderate= ly well, avoiding coil making and high voltage issues altogether. But to co= mpete with your vertical in terms of radiation resistance, it would need to= be really long, on the order of a couple of miles. It will have magnetic l= oop directional pattern which may be a disadvantage.
 
For a tran= satlantic detection eg. by Paul Nicholson, a Rubidium or GPS locked signal = source would be very beneficial. Using SpecLab with 1pps phase lock to elim= inate soundcard output glitches has worked well for DJ8WX, PA1SDB, and myse= lf.
 
Best of lu= ck,
Markus (DF6NM)


-----Urspr=C3=BCngliche Mitteilung-----
Von: DK7FC <73dk7fc@googlemail.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 24 Jun 2014 12:48 am
Betreff: Re: LF: VLF in Canada


Hi Joe, 

 

Fine to hear that you're give it a try. Please, don't ask Industry  

Canada if the 10mW is RF power of ERP! 

 

To get out a real signal on VLF, there is no alternative to a real large  <=
br>
coil without ferrites! Think about the high voltages... But 100m of  

antenna wire is a good start. I remember 550 mH for my 100m kite  

antenna. For me it was 2000m of 0.4mm diameter wire :-) Nice work is  

that. Takes long but is a funny game :-) 

 

73, GL, Stefan 

 

Am 23.06.2014 21:33, schrieb jcraig@mun.ca=
: 

Dear Group, 


I tried again to get an LOA  f=
or VLF.  This time, the response from  

Industry Canada was favourable: 10 mW 8.0-8.3 kHz.  Yesterday, after a  
few slight rf burns, and  thanks to PA0RDT's miniwhip design and  

DL4YHF's Spectrum Lab and advice, VLF sigs on 8.277 kHz were heard at  

200m from the 100m wire aerial. This was a reception outside my back  

yard!  10 watts from an 1970's keyboard amp (volume control set on 3)  

were stepped up with an xfmr to a lossy 500 ohm tuning coil peaked  

with a ferrite rod for maximum squeal at L=3D0.35 H. 


Is it possible for someone who=
 is not especially enthralled by winding 

a mile of 0.7mm wire to use an iron core to make a VLF tuning coil? 


73 

Joe VO1NA
----------MB_8D15DB1FFB761CE_2018_18405_webmail-d249.sysops.aol.com--