Return-Path: Received: from mtain-da01.r1000.mx.aol.com (mtain-da01.r1000.mx.aol.com [172.29.64.73]) by air-mf08.mail.aol.com (v129.4) with ESMTP id MAILINMF081-8bf54c9500222a0; Sat, 18 Sep 2010 14:08:34 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-da01.r1000.mx.aol.com (Internet Inbound) with ESMTP id E2C0A38000143; Sat, 18 Sep 2010 14:08:32 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Ox1oR-0007vm-3k for rs_out_1@blacksheep.org; Sat, 18 Sep 2010 19:06:59 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Ox1oG-0007vd-L0 for rsgb_lf_group@blacksheep.org; Sat, 18 Sep 2010 19:06:48 +0100 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Ox1oF-0002EQ-HD for rsgb_lf_group@blacksheep.org; Sat, 18 Sep 2010 19:06:49 +0100 Received: by bwz16 with SMTP id 16so4716296bwz.16 for ; Sat, 18 Sep 2010 11:06:47 -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=gc0XKmJ1fVgVgIKVqWpoVQdxk0uIV3/pwFAXrZWMqVw=; b=qw6U6NTQP0aMavquKJHWhC5kNRMQz/0N8yiD3oVEa3RoOi6tvH7XOk/w6W0S2pO5cl utog4Eto3IFWe2uNFmp1Lo4OKrqW/klQZM+I5HSweBgDx4KIkcy2AfloADnD3/Xa6zCg 6vIMwd3Fj8Ik6RzRh541dw9G1dfnjOKPQZFps= 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=EhB5AJXWbAoEKqNstuDs3ttV5XGnbzdpM02MWGikEgt9doW8+TuV/VVk8OaN0jYfsQ x1VrcKsnBp3z6dczktF/P0VgJDND/oY39PZA37lWYJMHtdLwhawIrD6oPbL1zx9r6gqd OE1sI0S+i/UhZPVDRAwQmbGgUn+JdtiowUy54= MIME-Version: 1.0 Received: by 10.204.137.80 with SMTP id v16mr5301878bkt.46.1284833206829; Sat, 18 Sep 2010 11:06:46 -0700 (PDT) Received: by 10.204.136.67 with HTTP; Sat, 18 Sep 2010 11:06:46 -0700 (PDT) In-Reply-To: <4C94FBCA.1060802@iup.uni-heidelberg.de> References: <4C94FBCA.1060802@iup.uni-heidelberg.de> Date: Sat, 18 Sep 2010 19:06:46 +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=0015173fe45ae3827404908c8a36 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,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-d266.1 ; domain : gmail.com DKIM : pass X-AOL-REROUTE: YES x-aol-sid: 3039ac1d40494c9500207878 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --0015173fe45ae3827404908c8a36 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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 > 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. > > 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 > > --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --0015173fe45ae3827404908c8a36 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Stefan (et al),

Still using the single IRF510 but driving it wit= h a better square wave now. I hope to change the design tomorrow to run fr= om 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 nea= rer the ground thereby increasing the loop area by another 20%. However th= is 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/s= een by 4 different stations in SE England and the WSPR reports already sug= gest further is possible.

This autumn is going to be a bundle of fun!

73s
Roger G3XBM<= br>

2010/9/18 Stefan Sch=E4fer <schaefer@iu= p.uni-heidelberg.de>
=20 =20
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://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> --0015173fe45ae3827404908c8a36--