Return-Path: Received: from mtain-md07.r1000.mx.aol.com (mtain-md07.r1000.mx.aol.com [172.29.96.91]) by air-dc06.mail.aol.com (v129.4) with ESMTP id MAILINDC063-86524c0e5b1c26b; Tue, 08 Jun 2010 11:00:44 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-md07.r1000.mx.aol.com (Internet Inbound) with ESMTP id ED3633800014D; Tue, 8 Jun 2010 11:00:41 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OM0H8-00028M-Og for rs_out_1@blacksheep.org; Tue, 08 Jun 2010 15:59:34 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OM0H8-00028D-0h for rsgb_lf_group@blacksheep.org; Tue, 08 Jun 2010 15:59:34 +0100 Received: from mtaout03-winn.ispmail.ntl.com ([81.103.221.49]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OM0H5-0004Sx-TF for rsgb_lf_group@blacksheep.org; Tue, 08 Jun 2010 15:59:33 +0100 Received: from know-smtpout-4.server.virginmedia.net ([62.254.123.1]) by mtaout03-winn.ispmail.ntl.com (InterMail vM.7.08.04.00 201-2186-134-20080326) with ESMTP id <20100608145915.DQEQ3075.mtaout03-winn.ispmail.ntl.com@know-smtpout-4.server.virginmedia.net>; Tue, 8 Jun 2010 15:59:15 +0100 Received: from [86.25.6.138] (helo=desktop) by know-smtpout-4.server.virginmedia.net with esmtp (Exim 4.63) (envelope-from ) id 1OM0Go-0007Ob-CM; Tue, 08 Jun 2010 15:59:15 +0100 From: "James Cowburn" To: Cc: "'Chris Osborn'" References: <002001cb070c$99d44b20$0401a8c0@xphd97xgq27nyf> ,<004201cb0713$7c295e10$0401a8c0@xphd97xgq27nyf> Date: Tue, 8 Jun 2010 15:59:10 +0100 Message-ID: <02c701cb071b$26cbc130$0217aac0@desktop> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 11 In-Reply-To: Thread-Index: AcsHFANgP5ib8PRlSeqLO7ht4xZT8AAAa2x7AAFNhlA= X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3664 X-Cloudmark-Analysis: v=1.1 cv=ZtHxNT4mZm3rCuM0SmWmgWxeBwJsziC8EqOrwwVkrhA= c=1 sm=0 a=q8OS1GolVHwA:10 a=F3M5lZpKAAAA:8 a=nN7BH9HXAAAA:8 a=4zyYRNuY2Y0PvHnGn1oA:9 a=W_LLHKRiueqsBEqWdFkA:7 a=jp6ZEpJyFX63v5XimMDtqCUHnOwA:4 a=CjuIK1q_8ugA:10 a=wk6s2zzMB60A:10 a=muIvw5a9-cgA:10 a=SSmOFEACAAAA:8 a=GVmooj4Cx9MvRovnzpIA:7 a=OUz4cDDbzjn5C4vR_01XOzI6HkgA:4 a=HpAAvcLHHh0Zw7uRqdWCyQ==:117 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: RE: RE: Re: RE: COIL WINDING THOUGHT Content-Type: multipart/alternative; boundary="----=_NextPart_000_02C8_01CB0723.88902930" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.2 required=5.0 tests=HTML_70_80, HTML_FONTCOLOR_UNKNOWN,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 x-aol-global-disposition: G x-aol-sid: 3039ac1d605b4c0e5b1902d9 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_02C8_01CB0723.88902930 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I think we'll do the single layer route and thus be readily upgradeable, rather than risk setting fire to Chris' shed and my garage!! B (or perhaps Mal, that was your evil plan all along..??!!!! :-) ) _____ From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Rik Strobbe Sent: 08 June 2010 15:20 To: rsgb_lf_group@blacksheep.org Subject: LF: RE: Re: RE: COIL WINDING THOUGHT Just had a look at a roll of 8 stranded wire (Belden) : it is rated 300Vrms Assuming an antenna capacitance of 500pF (= 35kOhm at 9kHz) you only need 8.5mA through the coil to generate 300V. 73, Rik ON7YD _____ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens mal hamilton [g3kevmal@talktalk.net] Verzonden: dinsdag 8 juni 2010 16:04 Aan: rsgb_lf_group@blacksheep.org Onderwerp: LF: Re: RE: COIL WINDING THOUGHT Jim and Co will hardly be involved with 30kv more like 3kv or less They will let us know g3kev ----- Original Message ----- From: Rik Strobbe To: rsgb_lf_group@blacksheep.org Sent: Tuesday, June 08, 2010 2:47 PM Subject: LF: RE: COIL WINDING THOUGHT Beware of the very high voltages between the strands. Stefan mentioned up to 30kV loading coil voltage, I guess even a fraction of this voltage will cause arcing between the strands In addition the high stray capacitance will reduce the Q. 73, Rik ON7YD _____ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens mal hamilton [g3kevmal@talktalk.net] Verzonden: dinsdag 8 juni 2010 15:15 Aan: rsgb Onderwerp: LF: COIL WINDING THOUGHT All vlf men Instead of winding miles of single strand insulated wire to achive the required inductance, use instead insulated multi strand wire and series the strands, normally the individual strands have coloured insulation and convenient to connect in series. also gather up all the ferrite cores you can find put into a suitable container and insert into coil. The above idea might save some coil winding time. another thouight while I am composing Litz wire. Get hold of some old Decca coils ( I have a couple) find the beginning and end and do the same as above, this however is more difficult although individually insulated they are all the same colour, but with a meter to identify each strand it can be done de mal/g3kev ------=_NextPart_000_02C8_01CB0723.88902930 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I think we̵= 7;ll do the single layer route and thus be readily upgradeable, rather than risk setting fire= to Chris’ shed and my garage!! B (or perhaps Mal, that was your evil plan all al= ong….??!!!!   J<= /span> )

 

 

From: owner-rsgb_lf_group@blac= ksheep.org [mailto:owner-= rsgb_lf_group@blacksheep.org] On Behalf Of Rik Strobbe
Sent: 08 June 2010 15:2= 0
To: rsgb_lf_group@blacksheep.org
Subject: LF: RE: Re: RE= : COIL WINDING THOUGHT

 

Just had a= look at a roll of 8 stranded wire (Belden) : it is rated 300Vrms

Assuming=  an antenna= capacitance of 500pF (=3D 35kOhm at 9kHz) you only need 8.5mA through the coil to generate 300V.=

 =

73, Rik&nb= sp; ON7YD

 =

Van: owner-rsg= b_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens mal hamilton [g3kevmal@talktalk.net]
Verzonden: dinsdag 8 ju= ni 2010 16:04
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: LF: Re: RE:= COIL WINDING THOUGHT=

Jim and Co= will hardly be involved with 30kv more like 3kv or less

They will= let us know<= span style=3D'font-size:8.0pt;font-family:Tahoma; color:black'>

g3kev=

 =

 =

----- Origi= nal Message -----

From: Rik Strobbe

To:<= span style=3D'font-size:10.0pt;font-family:Arial; color:black'> rsgb_lf_group@blacksheep.org <= /p>

Sent: Tues= day, June 08, 2010 2:47 PM

Subject:= LF: RE: COIL WINDING THOUGHT

 =

Beware of= the very high voltages between the strands.

Stefan men= tioned up to 30kV loading coil voltage, I guess even a fraction of this voltage will cause arcing bet= ween the strands<= /span>

In additio= n the high stray capacitance will reduce the Q.

 =

73, Rik&nb= sp; ON7YD

 =

Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens mal hamilton [g3kevmal@talktalk.net]
Verzonden: dinsdag 8 ju= ni 2010 15:15
Aan: rsgb
Onderwerp: LF: COIL WIN= DING THOUGHT<= /span>

All vlf men=

Instead of= winding miles of single strand insulated wire to achive the required inductance, use instead insulate= d multi strand wire and series the strands, normally the individual strands ha= ve coloured insulation and convenient to connect in series.=

also= <= /p>

gather up= all the ferrite cores you can find put into a suitable container and insert into coil.=

The above= idea might save some coil winding time.=

 =

another tho= uight while I am composing

 =

Litz wire.<= /span>

 =

Get hold of= some old Decca coils ( I have a couple) find the beginning and end and do the same as above, this ho= wever is more difficult although individually insulated they are all the same= colour, but with a meter to identify each strand it can be done<= font size=3D1 color=3Dblack face=3DTahoma>

 =

de mal/g3ke= v

 =

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