Return-Path: Received: from mtain-df06.r1000.mx.aol.com (mtain-df06.r1000.mx.aol.com [172.29.64.218]) by air-ma08.mail.aol.com (v129.4) with ESMTP id MAILINMA083-b5324d898bbd3a6; Wed, 23 Mar 2011 01:57:17 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 45168380000EE; Wed, 23 Mar 2011 01:57:15 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Q2H36-0004KP-DJ for rs_out_1@blacksheep.org; Wed, 23 Mar 2011 05:56:04 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Q2H35-0004KG-Jy for rsgb_lf_group@blacksheep.org; Wed, 23 Mar 2011 05:56:03 +0000 Received: from defout.telus.net ([204.209.205.13]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Q2H32-0001Tp-NW for rsgb_lf_group@blacksheep.org; Wed, 23 Mar 2011 05:56:03 +0000 Received: from edmwcm04 ([204.209.205.13]) by priv-edmwes25.telusplanet.net (InterMail vM.8.01.03.00 201-2260-125-20100507) with ESMTP id <20110323055557.OLGJ16923.priv-edmwes25.telusplanet.net@edmwcm04> for ; Tue, 22 Mar 2011 23:55:57 -0600 Received: from [192.168.1.74] ([75.157.141.251]) by edmwcm04 with bizsmtp id NVvw1g01J5Reinf01Vvxfy; Tue, 22 Mar 2011 23:55:57 -0600 X-Telus-Outbound-IP: 75.157.141.251 X-Authority-Analysis: v=1.1 cv=/+7n+KyXd92WYowfl1Q5CUL259JA/4/3Fq7ARM3wdw4= c=1 sm=2 a=jVez_htjv6wA:10 a=rK6R7I3HYpQA:10 a=CeXiu7uQAAAA:8 a=ZRMV4mFaWpzNxJNqU2MA:9 a=3uS48mhBSmgH4-47AP24rq0xXAQA:4 a=QEXdDO2ut3YA:10 a=kczAqott8TUbQ5sm2MgA:9 a=Fr7Rfv3OkSFsZdHADxrqseou8ZgA:4 Message-ID: <4D898B6C.2040403@telus.net> Date: Tue, 22 Mar 2011 22:55:56 -0700 From: Scott Tilley User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.15) Gecko/20110303 Lightning/1.0b2 Thunderbird/3.1.9 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <4D83D475.9090609@telus.net> <000b01cbe622$6a23f8d0$8d01a8c0@JAYDELL>, ,<4D86BD6F.8020006@telus.net> <4D8736CB.8040509@telus.net> <4D87E247.5020100@iup.uni-heidelberg.de> <8CDB69E4AD7AA3C-1490-33A81@webmail-m018.sysops.aol.com> <4D894947.6020405@iup.uni-heidelberg.de> In-Reply-To: <4D894947.6020405@iup.uni-heidelberg.de> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: Re: VLF: Resonate the antenna, or not? Content-Type: multipart/alternative; boundary="------------090004060104010605090106" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.3 required=5.0 tests=FROM_ENDS_IN_NUMS,HTML_20_30, 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: 3039ac1d40da4d898bba6c06 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : temperror X-Mailer: Unknown (No Version) --------------090004060104010605090106 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Stefan > The mains has just to supply the losses. So the critical parts are > the FETs and the loop wire diameter. I think 100 A rms is a problem > for most loops. But i would give it a try. Even the 4x or 5x 1.5 mm^2 > could take that current for a while, depending on the outside > temperature. BTW there will be a current limiting when the temperature > increases :-) The loop here is a #2 AWG (6.5mm) AL conductor. And yes I note considerable difference between cold days and warm ones on 2200m. Somewhere I have some measurements. > > Who is the one who does the first test? Scott? :-) BTW the distance > between VE7TIL and KL7UK is just 2084 km! > http://no.nonsense.ee/qthmap/?qth=CN89DK&from=bp51ip > I pulled the h-bridge design of yours from my files and found a version of this in my junk box... Now the magic question is when can I find time to rig this up? > Scott, what do you estimate is the current limit of your loop wire and > what is the area? And what is the bearing? Easily a couple hundred amps. 600m^2 and aimed right at Laurence. See my website 'station info.' > > 73, Stefan/ EI/DK7FC > > --------------090004060104010605090106 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi Stefan
=C2=A0 The mains has just to supply the losses. So the critical parts are the FETs and the loop wire diameter. I think 100 A rms is a problem for most loops. But i would give it a try. Even the 4x or 5x 1.5 mm^2 could take that current for a while, depending on the outside temperature. BTW there will be a current limiting when the temperature increases :-)
The loop here is a #2 AWG (6.5mm) AL conductor.=C2=A0 And yes I note considerable difference between cold days and warm ones on 2200m.=C2= =A0 Somewhere I have some measurements.


Who is the one who does the first test? Scott? :-) BTW the distance between VE7TIL and KL7UK is just 2084 km! h= ttp://no.nonsense.ee/qthmap/?qth=3DCN89DK&from=3Dbp51ip

I pulled the h-bridge design of yours from my files and found a version of this in my junk box...=C2=A0 Now the magic question is when can I find time to rig this up?

Scott, what do you estimate is the current limit of your loop wire and what is the area? And what is the bearing?

Easily a couple hundred amps.=C2=A0 600m^2 and aimed right at Laurence= .=C2=A0 See my website 'station info.'

73, Stefan/ EI/DK7FC



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