Return-Path: Received: from mtain-me10.r1000.mx.aol.com (mtain-me10.r1000.mx.aol.com [172.29.96.146]) by air-dd02.mail.aol.com (v129.4) with ESMTP id MAILINDD021-86084c950c8b113; Sat, 18 Sep 2010 15:01:31 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-me10.r1000.mx.aol.com (Internet Inbound) with ESMTP id C5FD73800008D; Sat, 18 Sep 2010 15:01:29 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Ox2NB-0008Ul-La for rs_out_1@blacksheep.org; Sat, 18 Sep 2010 19:42:53 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Ox2N1-0008Uc-1P for rsgb_lf_group@blacksheep.org; Sat, 18 Sep 2010 19:42:43 +0100 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Ox2N0-00048M-1j for rsgb_lf_group@blacksheep.org; Sat, 18 Sep 2010 19:42:44 +0100 Received: by bwz16 with SMTP id 16so4728995bwz.16 for ; Sat, 18 Sep 2010 11:41:52 -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=HLBLMFYMJOfJW+7kZtqMol+dgAmMcwEp6u2TIUFlrcs=; b=FOmg9lm6lAKIu2+PpdA9qA+DnUzd85E7ART8H33O6quhQvxpJd9R72i0SmJoUEhPzv P+mf+h6//bqfX1V2OhgiSzm540A58PbpbzKXeyyED4cNhKP4Z86dXC5EbNYK94tUT7LO zhE2XV4i8kJOsOawCm0Kd+mVoFpe6FuAj030w= 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=qJXjhMCKIfw47soowqvJnfkKFRBCnFNdJ9EWwwpT5whyj8FnPBexteprGFg6XlTXx6 ZA4avWGD+tCeke4nY6I74Xcz9vJuETUdOwp+kxrdBCxg0lJtILzYu/5OBurNQ/7uTgvF ng4BMC4z5FYFLZXaA8gOdLdg2JkFkC0EVQFrI= MIME-Version: 1.0 Received: by 10.204.102.197 with SMTP id h5mr5366428bko.24.1284835311950; Sat, 18 Sep 2010 11:41:51 -0700 (PDT) Received: by 10.204.136.67 with HTTP; Sat, 18 Sep 2010 11:41:51 -0700 (PDT) In-Reply-To: <4C9504C1.7010305@iup.uni-heidelberg.de> References: <4C94FBCA.1060802@iup.uni-heidelberg.de> <4C9504C1.7010305@iup.uni-heidelberg.de> Date: Sat, 18 Sep 2010 19:41:51 +0100 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.1 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,HTML_TAG_EXIST_TBODY=0.126 Subject: Re: LF: 137.5kHz WSPR success Content-Type: multipart/alternative; boundary=001636c5a4295d1a3a04908d0871 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30,HTML_MESSAGE, HTML_TAG_EXISTS_TBODY 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: S X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d246.1 ; domain : gmail.com DKIM : pass X-AOL-REROUTE: YES x-aol-sid: 3039ac1d60924c950c895e98 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --001636c5a4295d1a3a04908d0871 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable The loop area is perhaps 70m sq, but irregular in shape. If the weather is good tomorrow I will try to take a photo of it to share here. Now I have the WSPR transverter working I need to run some tests using the earth electrode antenna again with people like G3XIZ to compare gain, but initial tests on QRSS3 suggest there is maybe 6dB improvement with the "in the air" loop on 136kHz. I have still to do the local test where I go out= to the nearby carpark 1.6km away and measure signal levels directly. 838Hz tests are on hold whilst I play with 136kHz, but I hope to return to these soon. There are too few days in the week ...and I am retired, HI. Yes, I could run 20-25V with my existing PSU, so that is the easiest way= to increase ERP Stefan. 73s Roger g3XBM 2010/9/18 Stefan Sch=E4fer > Roger, > > This sound very hopefully and enthusiastic :-) What is the area of your > loop? And what is the "gain" compared to the earth antenna? Will you giv= e up > the earth antenna project? And what about your ULF (838 Hz) tests? > > For the IRF510 you can allow 20...25 V supply voltage, if well matched,= so > if the voltage is now 12...13.8 V you can double the voltage and get 6= dB > more power, so maybe twice the distance :-) > > 73 and keep us informated! > > Stefan/DK7FC > > > Am 18.09.2010 20:06, schrieb Roger Lapthorn: > > Hi Stefan (et al), > > Still using the single IRF510 but driving it with a better square wave= now. > I hope to change the design tomorrow to run from a higher supply rail an= d > realise another 3-4dB or so of ERP. The other simple change I can make > (later) is with my loop antenna, which is made from wire only 1mm diamet= er. > Increasing this to 4-5mm wire should reduce the losses another 3dB or mo= re. > I can also try running the lower part nearer the ground thereby increasi= ng > the loop area by another 20%. However this may introduce other losses. > > So far I am pleased with the results: with only around 4-5W from the PA,= a > very simple loop antenna with thin wire, tuned with a simple ATU on the > bedroom table using just a standard capacitance decade box, a simple 3C9= 0 > step-down transformer and a current meter, I've now been heard/seen by= 4 > different stations in SE England and the WSPR reports already suggest > further is possible. > > This autumn is going to be a bundle of fun! > > 73s > Roger G3XBM > > > 2010/9/18 Stefan Sch=E4fer > >> Hello Roger, >> >> Congrats to that distance and to the PA :-) Which FET is in use now? An= d >> how is the driver realised? >> >> 73 and GL, >> >> Stefan/DK7FC >> >> Am 18.09.2010 12:54, schrieb Roger Lapthorn: >> >> Some success this morning with my second ever 137kHz WSPR report, this >> time from *G3XIZ* who got me up to -23dB S/N during the morning. >> According to the WSPR database the distance is 46km. BTW, the PA is run= ning >> about 5W RF out (ERP about 10-20uW) in class-E with a nice cool heatsin= k. >> Next steps will be to increase the power and ERP. >> >> 2010-09-18 08:50 *G3XBM * 0.137534 -23 -1 JO02dg 0.001 >> G3XIZ IO92ub 46 240 >> Many thanks Chris, and everyone else please keep looking! >> >> 73s >> Roger G3XBM >> >> -- >> 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 > > --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --001636c5a4295d1a3a04908d0871 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable The loop area is perhaps 70m sq, but irregular in shape. If the weather is= good tomorrow I will try to take a photo of it to share here.

Now= I have the WSPR transverter working I need to run some tests using the ea= rth electrode antenna again with people like G3XIZ to compare gain, but in= itial tests on QRSS3 suggest there is maybe 6dB improvement with the "= ;in the air" loop on 136kHz. I have still to do the local test where= I go out to the nearby carpark 1.6km away and measure signal levels direc= tly.

838Hz tests are on hold whilst I play with 136kHz, but I hope to retur= n to these soon. There are too few days in the week ...and I am retired,= HI.

Yes, I could run 20-25V with my existing PSU, so that is the= easiest way to increase ERP Stefan.

73s
Roger g3XBM



2010/9/18= Stefan Sch=E4fer <schaefer@iup.uni-heidelberg.de>
=20
Roger,

This sound very hopefully and enthusiastic :-) What is the area of your loop? And what is the "gain" compared to the earth antenna? Will= you give up the earth antenna project? And what about your ULF (838 Hz) tests?

For the IRF510 you can allow 20...25 V supply voltage, if well matched, so if the voltage is now 12...13.8 V you can double the voltage and get 6 dB more power, so maybe twice the distance :-)

73 and keep us informated!

Stefan/DK7FC


Am 18.09.2010 20:06, schrieb Roger Lapthorn:
Hi Stefan (et= al),

Still using the single IRF510 but driving it with a better square wave now. I hope to change the design tomorrow to run from a higher supply rail and realise another 3-4dB or so of ERP. The other simple change I can make (later) is with my loop antenna, which is made from wire only 1mm diameter. Increasing this to 4-5mm wire should reduce the losses another 3dB or more. I can also try running the lower part nearer the ground thereby increasing the loop area by another 20%. However this may introduce other losses.

So far I am pleased with the results: with only around 4-5W from the PA, a very simple loop antenna with thin wire, tuned with a simple ATU on the bedroom table using just a standard capacitance decade box, a simple 3C90 step-down transformer and a current meter, I've now been heard/seen by 4 different stations in SE England and the WSPR reports already suggest further is possible.

This autumn is going to be a bundle of fun!

73s
Roger G3XBM


2010/9/18 Stefan Sch=E4fer = <sc= haefer@iup.uni-heidelberg.de>
Hello Roger,

Congrats to that distance and to the PA :-) Which FET is in use now? And how is the driver realised?

73 and GL,

Stefan/DK7FC

Am 18.09.2010 12:54, schrieb Roger Lapthorn:
Some success this morning with my second ever 137kHz WSPR report, this time from G3XIZ who got me up to -23dB S/N during the morning. According to the WSPR database the distance is 46km. BTW, the PA is running about 5W RF out (ERP about 10-20uW) in class-E with a nice cool heatsink. Next steps will be to increase the power and ERP.

=A02010-09-18 08:50=A0 =A0G3XBM=A0 =A00.137534=A0 =A0-23=A0 =A0-1=A0 =A0JO02dg=A0 =A00.001=A0 =A0G3XIZ=A0 =A0IO92ub=A0 =A046=A0 =A0240=A0

Many thanks Chris, and everyone else please keep looking!

73s
Roger G3XBM

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



--
http://g3xb= m-qrp.blogspot.com/
http://www.g3xbm.co= .uk
http://w= ww.youtube.com/user/g3xbm
G3XBM=A0=A0 GQRP 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> --001636c5a4295d1a3a04908d0871--