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[86.14.226.229]) by mx.google.com with ESMTPS id gb9sm18865920wib.8.2012.07.01.07.04.34 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 01 Jul 2012 07:04:35 -0700 (PDT) References: <4FEF4FAB.2010103@iup.uni-heidelberg.de> <628FB34D9D1741F2AB02D0ECEB380F01@64683d74b6134b3> <002c01cd5760$1d2a22b0$0401a8c0@xphd97xgq27nyf> From: Roger Lapthorn X-Mailer: iPod Mail (9B206) In-Reply-To: <002c01cd5760$1d2a22b0$0401a8c0@xphd97xgq27nyf> Message-Id: <24AD966C-1AD5-46D2-B472-D2EE77D62DB6@gmail.com> Date: Sun, 1 Jul 2012 15:04:34 +0100 To: "rsgb_lf_group@blacksheep.org" Mime-Version: 1.0 (1.0) X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: My (just) 20m spaced earth electrode antenna got plenty of WSPR reports with around 1mW ERP on 500kHz Mal with my best DX report received from 418km. Even on 136kHz my 10-20uW ERP QRSS3 signal got over 100km with this same antenna. On VLF it allowed me to copy DK7FC/P from his kite on 8.97kHz on my first try. He was much better on my 80m square loop though, which was erected later. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.212.181 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (rogerlapthorn[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 MIME_QP_LONG_LINE RAW: Quoted-printable line longer than 76 chars 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 131286aabc28dd54c072e5e89638c651 Subject: LF: Re: Earth electrode antennas Content-Type: multipart/alternative; boundary=Apple-Mail-7B5FC66D-7136-47B7-B855-DF376950BB56 Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,HTML_MESSAGE, TO_ADDRESS_EQ_REAL 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-SCOLL-SCORE: 0:2:456969920:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m023.2 ; domain : gmail.com DKIM : fail x-aol-sid: 3039ac1d41174ff0592c085c X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --Apple-Mail-7B5FC66D-7136-47B7-B855-DF376950BB56 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii My (just) 20m spaced earth electrode antenna got plenty of WSPR reports with= around 1mW ERP on 500kHz Mal with my best DX report received from 418km. Ev= en on 136kHz my 10-20uW ERP QRSS3 signal got over 100km with this same anten= na. On VLF it allowed me to copy DK7FC/P from his kite on 8.97kHz on my firs= t try. He was much better on my 80m square loop though, which was erected la= ter.=20 My 500kHz measurements suggested it was only about 8dB down on my 80m sq ver= tical loop that worked pretty well.=20 Summary: earth electrode antennas are not as good as a well elevated Marconi= or loop, but work surprisingly well considering how simple they are to exci= te and match.=20 73s Roger G3XBM -- Via my 2.4GHz transceiver -- On 1 Jul 2012, at 09:04, "mal hamilton" wrote: > Someone forgot to mention the 1 K/watt pumped into this antenna, no good f= or QRP merchants. > I tried this method years ago on a hotel flat roof in Hongkong and althoug= h I did work a few stations it was a POOR performer compared to the same dip= ole elevated --- big difference > I was running about 100 Watts to the dipole > There is no substitute for an Antenna being elevated into the air as high a= s possible except short range high angle communications is required, then a l= ow dipole has an advantage. > =20 > =20 > de mal/g3kev > =20 > =20 > ----- Original Message ----- > From: Robert Bennett > To: rsgb_lf_group@blacksheep.org > Sent: Saturday, June 30, 2012 8:40 PM > Subject: LF: Re: MF dipole >=20 >=20 > That means, for a MF dipole test i would start to try to lay it=20 > > on the ground. If this works with reasonable efficiency, so that a QSO=20= > > is possible, it would be a simple solution for a quick /p MF antenna=20 > > that can find its place in a back pack! > > >=20 > Like K3MT's Grasswire antenna?. >=20 > 73 Robert --Apple-Mail-7B5FC66D-7136-47B7-B855-DF376950BB56 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
My (just) 20m spaced earth= electrode antenna got plenty of WSPR reports with around 1mW ERP on 500kHz M= al with my best DX report received from 418km. Even on 136kHz my 10-20uW ERP= QRSS3 signal got over 100km with this same antenna. On VLF it allowed me to= copy DK7FC/P from his kite on 8.97kHz on my first try. He was much better o= n my 80m square loop though, which was erected later. 

My 500kHz measurements suggested it was only about 8dB down on m= y 80m sq vertical loop that worked pretty well. 

<= /div>
Summary: earth electrode antennas are not as good as a well elevat= ed Marconi or loop, but work surprisingly well considering how simple they a= re to excite and match. 

73s
Roger G= 3XBM

-- Via my 2.4GHz transceiver --

On 1 Jul 2012, at 0= 9:04, "mal hamilton" <g3kevmal@t= alktalk.net> wrote:

Someone forgot to mention the 1 K/watt pumped into= this=20 antenna, no good for QRP merchants.
I tried this method years ago on a hotel flat roof= in=20 Hongkong and although I did work a few stations it was a POOR performer comp= ared=20 to the same dipole elevated --- big difference
I was running about 100 Watts to=20 the dipole
There is no substitute for an Antenna being elevat= ed into=20 the air as high as possible except short range high angle communications is=20= required, then a low dipole has an advantage.
 
 
de mal/g3kev
 
 
----- Original Message -----
From:=20 Robert Bennett
Sent: Saturday, June 30, 2012 8:40=20= PM
Subject: LF: Re: MF dipole


 That means, for a MF dipole test i would start to= try=20 to lay it
> on the ground. If this works with reasonable efficiency= , so=20 that a QSO
> is possible, it would be a simple solution for a quick= /p=20 MF antenna
> that can find its place in a back=20 pack!
>

Like K3MT's Grasswire antenna?.

73=20 Robert
= --Apple-Mail-7B5FC66D-7136-47B7-B855-DF376950BB56--