Return-Path: Received: from mtain-df01.r1000.mx.aol.com (mtain-df01.r1000.mx.aol.com [172.29.64.213]) by air-de04.mail.aol.com (v126.13) with ESMTP id MAILINDE043-5eb04b4ce7af293; Tue, 12 Jan 2010 16:20:47 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-df01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2ABA638000114; Tue, 12 Jan 2010 16:20:46 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NUo8t-0001kG-Kt for rs_out_1@blacksheep.org; Tue, 12 Jan 2010 21:19:11 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NUo8t-0001k7-4F for rsgb_lf_group@blacksheep.org; Tue, 12 Jan 2010 21:19:11 +0000 Received: from smtp5.freeserve.com ([193.252.22.151] helo=smtp6.freeserve.com) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NUo8r-0001FS-4p for rsgb_lf_group@blacksheep.org; Tue, 12 Jan 2010 21:19:11 +0000 Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3509.me.freeserve.com (SMTP Server) with ESMTP id 80F09700009B for ; Tue, 12 Jan 2010 22:19:01 +0100 (CET) Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3509.me.freeserve.com (SMTP Server) with ESMTP id 749A970000A6 for ; Tue, 12 Jan 2010 22:19:01 +0100 (CET) Received: from AGB (unknown [91.109.7.57]) by mwinf3509.me.freeserve.com (SMTP Server) with SMTP id ED684700009B for ; Tue, 12 Jan 2010 22:18:58 +0100 (CET) X-ME-UUID: 20100112211858972.ED684700009B@mwinf3509.me.freeserve.com Message-ID: From: "Graham" To: References: <249428.56994.qm@web28106.mail.ukl.yahoo.com> In-Reply-To: <249428.56994.qm@web28106.mail.ukl.yahoo.com> Date: Tue, 12 Jan 2010 21:18:48 -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-Spam-Score: 0.1 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,HTML_TAG_EXIST_TBODY=0.126 Subject: Re: LF:Ice and frost on 600m antenna Content-Type: multipart/alternative; boundary="----=_NextPart_000_003C_01CA93CC.D4995330" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.0 required=5.0 tests=HTML_30_40,HTML_MESSAGE, HTML_TAG_EXISTS_TBODY,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-global-disposition: G x-aol-sid: 3039ac1d40d54b4ce7ae2158 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_003C_01CA93CC.D4995330 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Pete, The ice will be pure water and may not conduct .. will have some= capacity implications though ! G ..=20 From: M0FMT=20 Sent: Tuesday, January 12, 2010 1:51 PM To: rsgb_lf_group@blacksheep.org=20 Subject: LF:Ice and frost on 600m antenna Hi LF Group=20 =20 In an attempt to calculating the effect of ICE (Haw frost) on my= antenna I get these results.=20 With a wire diameter of 1.5mm flex weave, it comes out to 1.1 am= ps for 60 watts RF applied. This is confirmed crudely by observing a= pair of car festoon lamps (12Vx0.5A each) in parallel in the antenna= up lead glowing to full brightness.=20 With an estimated increase in antenna wire diameter to 10mm caus= ed by the Haw frost I did not notice any change in antenna current by= this method.=20 Running the calculation through using a 10mm wire I get 1.2 amps= and again to an absurd size of 20mm diameter there is virtually no in= crease in current.=20 =20 The recent WX at this location has had no noticeable effect on= the antenna. If it did I would suspect leakage through a dodgy insula= tor at the top of the inverted =E2=80=9CL=E2=80=9D up lead.=20 The type I use is a deeply ribbed glass insulator about 8 inches= long.=20 73 es GL petefmt =20 ------=_NextPart_000_003C_01CA93CC.D4995330 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable
Pete,
 
The ice will be  pure  wate= r  and=20 may not  conduct .. will have  some  capacity implicati= ons though=20 !
 
G ..

From: M0FMT
Sent: Tuesday, January 12, 2010 1:51 PM
Subject: LF:Ice and frost on 600m antenna


Hi LF Group= =20

 =20

In an attempt= to=20 calculating the effect of ICE (Haw frost) on my antenna I get th= ese=20 results.=20

With a wire= diameter of=20 1.5mm flex weave, it comes out to 1.1 amps for 60 watts RF appli= ed. This=20 is confirmed crudely by observing a pair of car festoon lamps (1= 2Vx0.5A=20 each) in parallel in the antenna up lead glowing to full brightn= ess.=20

With an estim= ated increase=20 in antenna wire diameter to 10mm caused by the Haw frost I did= not notice=20 any change in antenna current by this method.=20

Running the= calculation=20 through using a 10mm wire I get 1.2 amps and again to an absurd= size of=20 20mm diameter there is virtually no increase in current.=20

 =20

The recent WX= at this=20 location has had no noticeable effect on the antenna. If it did= I would=20 suspect leakage through a dodgy insulator at the top of the inve= rted =E2=80=9CL=E2=80=9D=20 up lead.=20

The type I us= e is a deeply=20 ribbed glass insulator about 8 inches long.=20


73 es GL=20 petefmt




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