Return-Path: Received: from rly-mg08.mx.aol.com (rly-mg08.mail.aol.com [172.20.83.114]) by air-mg05.mail.aol.com (v125.7) with ESMTP id MAILINMG052-a274af6e945227; Sun, 08 Nov 2009 10:52:49 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mg08.mx.aol.com (v125.7) with ESMTP id MAILRELAYINMG081-a274af6e945227; Sun, 08 Nov 2009 10:52:39 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1N7A3Q-00078j-TO for rs_out_1@blacksheep.org; Sun, 08 Nov 2009 15:51:48 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1N7A3Q-00078a-Dr for rsgb_lf_group@blacksheep.org; Sun, 08 Nov 2009 15:51:48 +0000 Received: from smtp5.freeserve.com ([193.252.22.151] helo=smtp6.freeserve.com) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1N7A2S-00018j-Jf for rsgb_lf_group@blacksheep.org; Sun, 08 Nov 2009 15:50:49 +0000 Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3524.me.freeserve.com (SMTP Server) with ESMTP id 79B301C00084 for ; Sun, 8 Nov 2009 16:51:41 +0100 (CET) Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3524.me.freeserve.com (SMTP Server) with ESMTP id 6CC351C00085 for ; Sun, 8 Nov 2009 16:51:41 +0100 (CET) Received: from AGB (unknown [91.109.45.11]) by mwinf3524.me.freeserve.com (SMTP Server) with SMTP id E20971C00084 for ; Sun, 8 Nov 2009 16:51:40 +0100 (CET) X-ME-UUID: 20091108155140925.E20971C00084@mwinf3524.me.freeserve.com Message-ID: <1E18FD2CB0EF4AD18696D0C843D75BFE@AGB> From: "Graham" To: References: <001b01ca6086$cd0966b0$0617aac0@jimdesk> In-Reply-To: <001b01ca6086$cd0966b0$0617aac0@jimdesk> Date: Sun, 8 Nov 2009 15:51:39 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 X-Karma: unknown: X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=disabled,HTML_FONT_BIG=0.256,HTML_MESSAGE=0.001 Subject: Re: LF: Losses due to ant in tree? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0053_01CA608B.5C614680" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.4 required=5.0 tests=HTML_50_60,HTML_FONT_BIG, 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 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_0053_01CA608B.5C614680 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Jim, Its very hard to estimate / guestimate may be move the decimal poi= nt, one place to the left , g4jnt beacon at 311Kmt is showing round= 10 db up on your signal at 243Kmt at the same time of day , If I am= right the power feed on wspr is -6db of the ral pulse/psk , making= power feed 25 watts=20 Similar power / similar distance / very similar bearing , 10 db less= , possibly 0.025 % ? ..... its all smoke and mirrors , perhaps= a little more smoke with wspr ?=20 G .. =20 From: James Cowburn=20 Sent: Sunday, November 08, 2009 3:19 PM To: rsgb_lf_group@blacksheep.org=20 Subject: LF: Losses due to ant in tree? Hi All, =20 The vertical 5m section of my inverted L runs up into the branches of= a silver birch tree. The wire goes over a large bough at 5m or so an= d then comes out of the branches for some 22m down to a 4m high pole= attached to the garage. =20 Has anyone a guesstimation of the losses in signal caused by running= the wire through the tree? =20 Using vertload and tophat2 I calculate the antenna to be around 0.25%= efficient but this assumes it is in free space. Can anyone suggest= a figure for the additional loss due to tree heating! =20 The vertical element is actually sloping at about 20 degree from the= tree down to the loading coil. The length is nearer 6metres but the= vertical height over ground at the bough is about 5m. =20 (Santa may be bringing me a set of swaged poles with which to build ma= rk 2, well away from the silver birch!) =20 With best regards =20 =20 Jim =20 =20 Dr. James Cowburn G7NKS ------=_NextPart_000_0053_01CA608B.5C614680 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Jim,
 
Its very hard to  estimate / gue= stimate =20 may be  move the  decimal point, one place to the  left= , g4jnt=20 beacon at  311Kmt is showing  round 10 db up on your signal= at 243Kmt=20 at the same time of day  , If  I am right the  pow= er=20 feed  on wspr is -6db  of the ral pulse/psk , making power&n= bsp; feed=20 25 watts 
 
Similar power / similar distance / ve= ry similar=20 bearing , 10 db less  , possibly  0.025 % ? .....  its= all =20 smoke and  mirrors , perhaps a little  more  smoke with= wspr=20 ? 
 
G ..  
Sent: Sunday, November 08, 2009 3:19 PM
Subject: LF: Losses due to ant in tree?

Hi All,

 

The vertical 5m section of my=20 inverted L runs up into the branches of a silver birch tree.  The= wire goes=20 over a large bough at 5m or so and then comes out of the branches for= some 22m=20 down to a 4m high pole attached to the garage.

 

Has anyone a guesstimation of the=20 losses in signal caused by running the wire through the=20 tree?

 

Using vertload and tophat2 I=20 calculate the antenna to be around 0.25% efficient but this assumes it= is in=20 free space.  Can anyone suggest a figure for the additional loss= due to=20 tree heating!

 

The vertical element is actually=20 sloping at about 20 degree from the tree down to the loading coil. &nb= sp;The=20 length is nearer 6metres but the vertical height over ground at the bo= ugh is=20 about 5m.

 

(Santa may be bringing me a set of=20 swaged poles with which to build mark 2, well away from the silver=20 birch!)

 

With best=20 regards

 

 

= Jim

 

 

Dr. James Cowburn=20 G7NKS



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