Return-Path: X-Spam-DCC: paranoid 1102; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id t7FHxXPa015618 for ; Sat, 15 Aug 2015 19:59:33 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZQfhE-0006OW-35 for rs_out_1@blacksheep.org; Sat, 15 Aug 2015 18:56:44 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZQfhD-0006ON-QE for rsgb_lf_group@blacksheep.org; Sat, 15 Aug 2015 18:56:43 +0100 Received: from rhcavuit01.kulnet.kuleuven.be ([134.58.240.129] helo=cavuit01.kulnet.kuleuven.be) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1ZQffr-0007ch-Hu for rsgb_lf_group@blacksheep.org; Sat, 15 Aug 2015 18:56:42 +0100 X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-KULeuven-Scanned: Found to be clean X-KULeuven-ID: 33544138098.AEE46 X-KULeuven-Information: Katholieke Universiteit Leuven Received: from icts-p-smtps-2.cc.kuleuven.be (icts-p-smtps-2e.kulnet.kuleuven.be [134.58.240.34]) by cavuit01.kulnet.kuleuven.be (Postfix) with ESMTP id 33544138098 for ; Sat, 15 Aug 2015 19:55:02 +0200 (CEST) Received: from ICTS-S-HUB1.luna.kuleuven.be (icts-s-hub1.luna.kuleuven.be [10.112.9.15]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by icts-p-smtps-2.cc.kuleuven.be (Postfix) with ESMTPS id A95FC20098 for ; Sat, 15 Aug 2015 19:54:57 +0200 (CEST) Received: from ICTS-S-MBX1.luna.kuleuven.be ([fe80::edaf:341f:90e:f70e]) by ICTS-S-HUB1.luna.kuleuven.be ([fe80::f5f7:d8cc:bee0:28d3%26]) with mapi id 14.03.0224.002; Sat, 15 Aug 2015 19:54:57 +0200 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" Thread-Topic: LF: Re: RE: Folded monopole - Food for thought Thread-Index: AQHQ1tkpqWjDg32ekUCMkyVhSQoM6Z4L48WAgAFMroCAACgjHA== Date: Sat, 15 Aug 2015 17:54:56 +0000 Message-ID: <7E7DFBB4D102A04DB5ADC88D66628A4A443F4C99@ICTS-S-MBX1.luna.kuleuven.be> References: <1156BF06E81A40ED928F77349725D23D@gnat> ,<99F1F2B22A504C2E817619D82E59C59B@Clemens0811> In-Reply-To: <99F1F2B22A504C2E817619D82E59C59B@Clemens0811> Accept-Language: nl-BE, en-GB, en-US Content-Language: nl-BE X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.112.13.11] MIME-Version: 1.0 X-HELO-Warning: Remote host 134.58.240.129 (rhcavuit01.kulnet.kuleuven.be) used invalid HELO/EHLO cavuit01.kulnet.kuleuven.be - verification failed X-Scan-Signature: d7fcd9b75df8d1b09ddef9df028bd9ae Subject: RE: LF: Re: RE: Folded monopole - Food for thought Content-Type: text/plain; charset="us-ascii" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by paranoid.lipkowski.org id t7FHxXPa015618 Status: O X-Status: X-Keywords: X-UID: 3881 HI Clemens, but on LF Rrad <<< Rloss, in that case it is very close to 6dB. And often adding a topload wire will decrease Rloss (footprint theory), so the actue gain will often be more than 6dB. 73, Rik ON7YD - OR7T ________________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org] namens Clemens Paul [cpaul@gmx.net] Verzonden: zaterdag 15 augustus 2015 19:28 Aan: rsgb_lf_group@blacksheep.org Onderwerp: RE: LF: Re: RE: Folded monopole - Food for thought Hi Andy, >6dB more, not 3dB >Height squared I believe it's neither 3dB nor 6dB increase for ERP. What is squared by doubling the effective height is is Rrad. The increase in ERP is by far not so high and depends much on Rloss (ground and matching). Example: Rrad = 50 Ohm; Rloss = 50 Ohm => efficiency = 0.5 Quadruple Rrad to 200 Ohm then efficiency = 0.8 => 2dB more. Other Rloss values give completeley different numbers for efficiency. 73 Clemens DL4RAJ >-----Original Message----- >From: owner-rsgb_lf_group@blacksheep.org >[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Andy Talbot >Sent: Friday, August 14, 2015 10:38 PM >To: rsgb_lf_group@blacksheep.org >Subject: Re: LF: Re: RE: Folded monopole - Food for thought > >6dB more, not 3dB >Height squared > >'jnt > > >On 14 August 2015 at 22:31, Alan Melia > wrote: > > > The problem with a monopole at LF is that the effective >height is only half (approx) the physical height. For an >inverted L where the top length is at least twice the height, >the effective height is close to the physical height .....so >3dB more ERP. It may not matter so much on 160m (I used a >16foot centre loaded "tank-whip" at one time :-)) ) but where > >