Return-Path: Received: from mtain-ma04.r1000.mx.aol.com (mtain-ma04.r1000.mx.aol.com [172.29.96.12]) by air-db09.mail.aol.com (v129.4) with ESMTP id MAILINDB092-86234c8684041d3; Tue, 07 Sep 2010 14:27:16 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-ma04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 5A0BC38000126; Tue, 7 Sep 2010 14:27:14 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Ot2re-0001ig-QJ for rs_out_1@blacksheep.org; Tue, 07 Sep 2010 19:25:50 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Ot2re-0001iX-9A for rsgb_lf_group@blacksheep.org; Tue, 07 Sep 2010 19:25:50 +0100 Received: from out1.ip06ir2.opaltelecom.net ([62.24.128.242]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Ot2rY-0000L4-Qw for rsgb_lf_group@blacksheep.org; Tue, 07 Sep 2010 19:25:50 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgcFAJgghkxOk8kR/2dsb2JhbACPaQORCnEPwRGFPQSBWYtN X-IronPort-AV: E=Sophos;i="4.56,329,1280703600"; d="scan'208,217";a="470682178" Received: from unknown (HELO xphd97xgq27nyf) ([78.147.201.17]) by out1.ip06ir2.opaltelecom.net with SMTP; 07 Sep 2010 19:25:37 +0100 Message-ID: <002501cb4eba$10919110$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: Date: Tue, 7 Sep 2010 19:25:10 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: 137.5kHz WSPR Tuesday evening - reports appreciated Content-Type: multipart/alternative; boundary="----=_NextPart_000_0022_01CB4EC2.635751C0" 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_FONTCOLOR_UNSAFE,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-sid: 3039ac1d600c4c8684010a97 X-AOL-IP: 193.82.116.20 X-AOL-SPF: domain : blacksheep.org SPF : temperror ------=_NextPart_000_0022_01CB4EC2.635751C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable In that case I can see why it blew up!! g3kev ----- Original Message -----=20 From: Roger Lapthorn=20 To: rsgb_lf_group@blacksheep.org ; Chris Osborn ; G6ALB ; James Cowb= urn ; Chris Dillon ; James Moritz ; mike.dennison@ntlworld.com=20 Sent: Tuesday, September 07, 2010 7:17 PM Subject: Re: LF: 137.5kHz WSPR Tuesday evening - reports appreciated Just hit a bit of a snag and blew up my (last) IRF510 PA because of= totally inadequate heatsink. So, I'm on 137.5kHz WSPR but only with= about 1W from the simpler PA at present, so ERP low uWs. I need to= get some heatsink and more FETs! Any reports (now less likely) still appreciated. [Mal - it started out as a Class E design attempt but hadn't been op= timised, so I guess this counts as class D. ] 73s Roger G3XBM On 7 September 2010 17:34, Roger Lapthorn = wrote: My 137.5kHz WSPR TX transverter is now working fine, so I'll be on= -air with WSPR tonight (Sept 7th) from 5.30pm - 11pm UK time.=20 After my success on QRSS3 with G3XIZ I'm hopeful he'll now decode= my WSPR signal tonight, assuming Chris can take a listen. If anyone= else within, say, 100km of Burwell, Cambs JO02dg cares to take a look= for the WSPR beacon (running around 35% TX time) I'd be most grateful= .=20 Not sure if anyone else has had this problem, but I was using the= small 16mm 3C90 cores (cream colour) as the PA bifilar output transfo= rmer and I had all sorts of issues with the darn thing overheating and= even one cracking. I replaced this with a choke wound on a T106-2 cor= e and made the output network work in class D/E and now everything is= working very predictably. The larger diameter 3C90 cores seem fine in= the step-down transformer matching the "in the air" loop. The WSPR beacon is now going ON..... 73s Roger G3XBM --=20 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 ------=_NextPart_000_0022_01CB4EC2.635751C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
In that case I can see why it blew=20 up!!
g3kev
 
----- Original Message -----
Sent: Tuesday, September 07,= 2010 7:17=20 PM
Subject: Re: LF: 137.5kHz WSP= R Tuesday=20 evening - reports appreciated

Just hit a bit of a snag and blew up my (last) IRF510= PA=20 because of totally inadequate heatsink. So, I'm on 137.5kHz WSPR but= only with=20 about 1W from the simpler PA at present, so ERP low uWs.  I nee= d to get=20 some heatsink and more FETs!

Any reports (now less likely) st= ill=20 appreciated.

[Mal - it started out as a Class E design attemp= t but=20 hadn't been optimised, so I guess this counts as class D.=20 ]

73s
Roger G3XBM



On 7 September 2010 17:34, Roger Lapthorn= <rogerlapthorn@gmail.com>=20 wrote:
My=20 137.5kHz WSPR TX transverter is now working fine, so I'll be on-air=20 with WSPR tonight (Sept 7th) from 5.30pm - 11pm UK time.= =20

After my success on QRSS3 with G3XIZ I'm hopeful he'll now= decode my=20 WSPR signal tonight, assuming Chris can take a listen. If anyone= else=20 within, say, 100km of Burwell, Cambs JO02dg cares to take a look= for the=20 WSPR beacon (running around 35% TX time) I'd be most gratef= ul.=20

Not sure if anyone else has had this problem, but I was= using=20 the small 16mm 3C90 cores (cream colour) as the PA bifilar output= =20 transformer and I had all sorts of issues with the darn thing over= heating=20 and even one cracking. I replaced this with a choke wound on a T10= 6-2 core=20 and made the output network work in class D/E and now everything= is working=20 very predictably. The larger diameter 3C90 cores seem fine in the= step-down=20 transformer matching the "in the air" loop.

The WSPR beacon= is now=20 going ON.....

73s
Roger G3XBM
<= BR clear=3Dall>
--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm= .co.uk
http://www.youtube.com/user/g3xbm
G3XBM&nbs= p; =20 GQRP 1678    ISWL G11088



--
http://g3xbm-qrp.blogspot.com/
<= A href=3D"http://www.g3xbm.co.uk" target=3D_blank>http://www.g3xbm= .co.uk
http://www.youtube.com/user/g3xbm
G3XBM &nbs= p; GQRP=20 1678    ISWL G11088
------=_NextPart_000_0022_01CB4EC2.635751C0--