Return-Path: Received: from mtain-ma02.r1000.mx.aol.com (mtain-ma02.r1000.mx.aol.com [172.29.96.10]) by air-di07.mail.aol.com (v129.4) with ESMTP id MAILINDI073-ead04c6307ac319; Wed, 11 Aug 2010 16:27:24 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-ma02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 612E838000EA6; Wed, 11 Aug 2010 16:27:22 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OjHs4-0003Xo-0D for rs_out_1@blacksheep.org; Wed, 11 Aug 2010 21:25:56 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OjHs2-0003Xf-ON for rsgb_lf_group@blacksheep.org; Wed, 11 Aug 2010 21:25:54 +0100 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OjHs0-0004Nj-Ax for rsgb_lf_group@blacksheep.org; Wed, 11 Aug 2010 21:25:54 +0100 Received: by bwz6 with SMTP id 6so97941bwz.16 for ; Wed, 11 Aug 2010 13:25:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=X/3Q1n3Q8tSqWVf7ZItCZB7iBNZ8aeL7tLzVPAT9r28=; b=V+F7uWAoRq3+7CQ7bFv+bSXfxQPVwKYrld8s9IxuQ87tZUBIkKB2ZrIvuD54sfPWEW +1He3m6q7hDWkRxKyTQw3pnmiXy1NH74/zUhWB9EG+NEjNmN6sdrvyqKJLUgRZ6IkXWs iF87idSB9iIejwo5yDWMiERAYtRZW+qKn0qrY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=NboZ1BsSAsRK033kbaJ87k0/Q/SA1ojAW034VvkgZq6lr1nKSXaDkZ9yXlYaQiH8t5 gHUFrDGHN/JHLlDq+pIfh1yHFZEr3jCRQZI88dkvGpsFjTLKCI8AGbtNsZpjrUpvZ5i1 AdH4fPu1Wz0VqZtiq17lokPDklQQqrlTPFYaM= MIME-Version: 1.0 Received: by 10.204.82.136 with SMTP id b8mr5525437bkl.38.1281558351429; Wed, 11 Aug 2010 13:25:51 -0700 (PDT) Received: by 10.204.194.69 with HTTP; Wed, 11 Aug 2010 13:25:51 -0700 (PDT) In-Reply-To: <002e01cb3989$4bfb8a30$0401a8c0@xphd97xgq27nyf> References: <002001cb397a$055bd990$0401a8c0@xphd97xgq27nyf> <002e01cb3989$4bfb8a30$0401a8c0@xphd97xgq27nyf> Date: Wed, 11 Aug 2010 21:25:51 +0100 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: ERP DISTANCE ETC Content-Type: multipart/alternative; boundary=0016e6d641b34bc254048d920e71 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=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-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m243.2 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d600a4c6307aa487a X-AOL-IP: 193.82.116.20 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --0016e6d641b34bc254048d920e71 Content-Type: text/plain; charset=ISO-8859-1 Thanks Mal. Yes, I agree the margin of error is quite large, but trying to measure ERP by taking accurate field strength measurements some 10s of kms away from the QTH seems a reasonable aim to me. I'm learning something by doing this and the inputs today from Alan, Jim and Rik have been very helpful. BTW, I agree that QRP is often, but not always, successful because of people, like you, with good equipment and ears taking the trouble to listen for and work weak signals. I appreciate this. This was certainly the case last winter in my tests on 500kHz. Incidentally, I'm sure I'll copy you on 8.97kHz in due course and look forward to your signal when the band becomes available for radiated tests by NoV. Good luck when this happens. 73s Roger G3XBM On 11 August 2010 20:13, mal hamilton wrote: > The trouble is that these misleading figures get published and then some > think that the world can be worked using uWatts on LF when in fact it CANNOT > Your figures quoted earlier then modified by others all conflict depending > on speculation or guesswork, everyone has a go. The outcome is usually as I > have previously stated arrive at a figure then it could be plus/minus by up > to 10 dB which is a lot, this renders the experiment meaningless. > My argument is not a criticism of individuals and what they do but the > misleading figures and calculations produced that could misguide others. > QRP merchants like to get reports from well equipped stations with proper > elevated antennas, there is little or no chance of them hearing each other, > In all walks of life there is disagreement, scientist for example. > Building a suitable amplifier to generate 1W erp on 137 Kcs or 10W erp on > 500 Kcs would be preferable to watching TV. > I am ready both RX and TX on CW for 8.97 Kcs and would immediately build a > suitable rf amplifier if the band becomes available for TX in the UK > I can guarantee you will hear me if you use an elevated antenna suitable > for purpose. > > G3KEV > > > ----- Original Message ----- > *From:* Roger Lapthorn > *To:* rsgb_lf_group@blacksheep.org > *Sent:* Wednesday, August 11, 2010 6:44 PM > *Subject:* Re: LF: ERP DISTANCE ETC > > Mal, > > Thanks again for the great encouragement. Would you prefer we just watched > TV instead and gave up the hobby? > > Here, I've *no interest* in running high power on *any* band, rather I > want to see what I can achieve with low power, simple rigs and simple > antennas. If this results in my best DX being only 20-30km then so be it. > > As for your comment on earth antennas, I beg to differ. There is still a *great > deal* to be explored and understood in this area on all bands from > sub-9kHz to at least 500kHz. > > 73s > Roger G3XBM > > > > > > On 11 August 2010 18:24, mal hamilton wrote: > >> Lots of figures appearing on here at present are guesswork and >> misleading. This has happened in the past trying to guess who was running >> what power, then the conclusion was + or - 6 to 10 dB wich is nonsense ie >> could be !W or 4W or !W or 10W. For those complaining about no room for >> large antennas, use the best elevated antenna you can get up and run several >> K/Watts to achieve the required ERP. >> Earth antennas have also been tested in the past are only useful for Cave >> radio communications, the wheel keeps being reinvented here on LF. >> G3KEV >> >> > > > > -- > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > http://www.youtube.com/user/g3xbm > G3XBM GQRP 1678 ISWL G11088 > > -- http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --0016e6d641b34bc254048d920e71 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks Mal.

Yes, I agree the margin of error is quite large, but tr= ying to measure ERP by taking accurate field strength measurements some 10= s of kms away from the QTH seems a reasonable aim to me. I'm learning= something by doing this and the inputs today from Alan, Jim and Rik have= been very helpful.

BTW, I agree that QRP is often, but not always, successful because of= people, like you,=20 with good equipment and ears taking the trouble to listen for and work wea= k=20 signals.=A0 I appreciate this. This was certainly the case last winter in= my tests on 500kHz.

Incidentally, I'm sure I'll copy you= on 8.97kHz in due course and look forward to your signal when the band be= comes available for radiated tests by NoV. Good luck when this happens.
73s
Roger G3XBM




On 11= August 2010 20:13, mal hamilton <g3kevmal@talktalk.net> wrote:
The trouble is that these misleading= figures get=20 published and then some think that the world can be worked using uWatts on= LF=20 when in fact it CANNOT
Your figures quoted earlier then modi= fied by others=20 all conflict depending on speculation or guesswork, everyone has a go. The= =20 outcome is usually as I have previously stated arrive at a figure then it= could=20 be plus/minus by up to 10 dB which is a lot, this renders the experiment= =20 meaningless.
My argument is not a criticism of ind= ividuals and=20 what they do=A0but the misleading figures and calculations produced that= =20 could misguide others.
QRP merchants like to get reports fro= m well=20 equipped stations with proper elevated antennas, there is little or no cha= nce of=20 them=A0hearing each other,
In all walks of life there is=20 disagreement,=A0scientist for example.
Building a=A0suitable amplifier to=A0= generate=20 1W erp on 137 Kcs or 10W=A0erp on 500=A0Kcs would be preferable to=20 watching TV.
I am ready both RX and TX on CW for= 8.97 Kcs and=20 would immediately build a suitable rf amplifier if the band becomes availa= ble=20 for TX in the UK
I can guarantee you will hear me if= you use an=20 elevated antenna suitable for purpose.
=A0
G3KEV
=A0
----- Original Message -----
To: rsgb_lf_group@blacksheep.org=20
Sent: Wednesday, August 11, 2010 6:44=20 PM
Subject: Re: LF: ERP DISTANCE ET= C

Mal,

Thanks again for the great encouragement. Wou= ld you=20 prefer we just watched TV instead and gave up the hobby?

Here, I&= #39;ve=20 no interest in running high power on any band, rather I wa= nt to=20 see what I can achieve with low power, simple rigs and simple antennas.= If=20 this results in my best DX being only 20-30km then so be it.

As= for=20 your comment on earth antennas, I beg to differ. There is still a gre= at=20 deal to be explored and understood in this area on all bands from su= b-9kHz=20 to at least 500kHz.

73s
Roger G3XBM





On 11 August 2010 18:24, mal hamilton <g3kevmal@talktalk.net>=20 wrote:
Lots of figures appearing on here= at present=20 are guesswork and misleading. This has happened in the past trying to= guess=20 who was running what power, then the conclusion was + or - 6 to 10 dB= wich=20 is nonsense ie could=A0be !W or 4W or !W or 10W. For those complaining= =20 about no room for large antennas, use the best elevated antenna you ca= n get=20 up and run several K/Watts to achieve the required ERP.
Earth antennas have also been tes= ted in the=20 past are only useful for Cave radio communications, the wheel keeps be= ing=20 reinvented here on LF.
G3KEV
=A0



-- http://g3xb= m-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www= .youtube.com/user/g3xbm
G3XBM=A0=A0 GQRP=20 1678=A0=A0=A0 ISWL G11088



--
http://g3xbm-qrp.blogspot.com/<= br>http://www.g3xbm.c= o.uk
http://www= .youtube.com/user/g3xbm
G3XBM=A0=A0 GQRP 1678=A0=A0=A0 ISWL G11088<= br> --0016e6d641b34bc254048d920e71--