Return-Path: Received: from mtain-df01.r1000.mx.aol.com (mtain-df01.r1000.mx.aol.com [172.29.64.213]) by air-mf04.mail.aol.com (v129.4) with ESMTP id MAILINMF042-8be64c8697ed1fe; Tue, 07 Sep 2010 15:52:13 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-df01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 75A5938000118; Tue, 7 Sep 2010 15:52:11 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Ot4Bm-0002Nu-Fl for rs_out_1@blacksheep.org; Tue, 07 Sep 2010 20:50:42 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Ot4Bl-0002Nl-Lf for rsgb_lf_group@blacksheep.org; Tue, 07 Sep 2010 20:50:41 +0100 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Ot4Bg-0000oT-BD for rsgb_lf_group@blacksheep.org; Tue, 07 Sep 2010 20:50:42 +0100 Received: by bwz16 with SMTP id 16so5273372bwz.16 for ; Tue, 07 Sep 2010 12:50:35 -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=vY0BgJsQF3VM2tjmpYXHMg+16DKyrFnlf6jXwBzO1Bw=; b=w/547ZJ/5KjHW66Hk8jm2sRQurpzoLYsTrVyB8G2cZVZBpj3VgTNY95FPiEo+VP3RN EPmq+yhPCNh/7e4PShLM+Ob8SJtMdIgHTyVlxiWERrUpN5T6uj1hXQIuSDE7MmiJR1hl Xg6UkunoIG0Cq6VZ8dIIpGtnNvnoz3YbcyXgM= 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=U2X3DhtX7Wg5tN0HE/Qsj8bJk4jocMzzkwkQp2ayFA90GznwlRHcR+iSRy+Tif5Fag +SKrB1OJ5+n1+T9BA2w1n5jnm3nrvdgtNvc6Rc+tDqAQFEUsPcBvdBiZo5nvnz4N23VL Tj7MjyewQZ9EB7g6sDfRFCT+KFjdBfh0ZoL+E= MIME-Version: 1.0 Received: by 10.204.142.92 with SMTP id p28mr4482216bku.2.1283889030927; Tue, 07 Sep 2010 12:50:30 -0700 (PDT) Received: by 10.204.136.67 with HTTP; Tue, 7 Sep 2010 12:50:30 -0700 (PDT) In-Reply-To: References: <4C8686CF.9060100@iup.uni-heidelberg.de> Date: Tue, 7 Sep 2010 20:50:30 +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: 137.5kHz WSPR Tuesday evening - reports appreciated Content-Type: multipart/alternative; boundary=0015174befce9e9571048fb0b51f 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_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-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d262.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d40d54c8697eb5f6f X-AOL-IP: 193.82.116.20 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --0015174befce9e9571048fb0b51f Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 103% efficient??? You've solved the world's energy crisis Andy :-) BTW, thanks for the class E tips. 73s Roger G3XBM On 7 September 2010 20:32, Andy Talbot wrote: > Take a look at G3NYK's Class E design page > http://www.alan.melia.btinternet.co.uk/classepa.htm > > Don't even try biassing the FET with a pot. You must use a squarewave > drive- preferrable from a proper MOSFET driver like an ICL7667 or TC4426 > type, or at a push a stack of paralleled 74C drivers will do. > > I measured somewhere between 85 - 103% efficiency for a 20 Watt design > running from 12V on 1.9MHz. Its very difficult to measure PA efficiency > properly at low frequencies as the HP432 power meter doesn't go below > 10MHz Judging by how not-hot the device got, looks to be around 90%. > See the next RadCom for more details. > > > Andy > www.g4jnt.com > > > On 7 September 2010 20:08, Roger Lapthorn wrot= e: > >> Stefan/Mal, >> >> Clearly my design was not working in class E properly as the PA was >> dissipating a fair amount of heat and it was taking about 0.8A to produ= ce >> 40V p-p output from a 13.8V supply which is about half as efficient as= it >> should be. I took a PA design start from a design program I found on th= e net >> by Tonne Software called "Class E" and the values seemed to be close to >> optimum when I adjusted caps and L up and down a small amount, but the >> dissipation seems miles off what a good class E design should take. The >> IRF510 gate voltage is set just below 3V with a resistive pot. The driv= e is >> not a square wave though, so I suppose this could be part of the issue? >> >> Stefan, if you have a better class E PA circuit for 137kHz suitable for >> around the 10-20W out region I'd be interested in seeing it. I would pr= efer >> to use toroid inductors because of size. I have several T106-2 cores to= hand >> as well as several 16mm diameter 3C90 cores. >> >> I'm still learning..... and not too proud to ask for help from those wi= th >> more experience. >> >> 73s >> Roger G3XBM >> >> >> >> >> >> 2010/9/7 Stefan Sch=E4fer >> >>> Hello Roger, >>> >>> Maybe you can send us a circuit with its values. I have built class E= PA >>> for 2200/160/80/40/30/17/10m and have some experience. If you are usin= g a >>> IRF510 and stay in the QRP range (< 10 W) at 137 in a class E stage yo= u >>> wouldn't even need a heat sink at all if well dimensioned! >>> >>> See the infos at http://www.classeradio.com/ This is most useful if= you >>> are starting with that design. On 137 kHz problems are much smaller th= an on >>> HF :-) >>> >>> Best 73, Stefan/DK7FC >>> >>> Am 07.09.2010 20:17, schrieb Roger Lapthorn: >>> >>> 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 ab= out 1W >>> from the simpler PA at present, so ERP low uWs. I need to get some he= atsink >>> and more FETs! >>> >>> Any reports (now less likely) still appreciated. >>> >>> [Mal - it started out as a Class E design attempt but hadn't been >>> optimised, so I guess this counts as class D. ] >>> >>> 73s >>> Roger G3XBM >>> >>> >>> >>> On 7 September 2010 17:34, Roger Lapthorn wro= te: >>> >>>> My 137.5kHz WSPR TX transverter is now working fine, so I'll be *on-a= ir >>>> with WSPR tonight (Sept 7th) from 5.30pm - 11pm UK time*. >>>> >>>> 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. >>>> >>>> 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 eve= n one >>>> cracking. I replaced this with a choke wound on a T106-2 core and mad= e 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-dow= n >>>> transformer matching the "in the air" loop. >>>> >>>> The WSPR beacon is now going ON..... >>>> >>>> 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 >>> >>> >> >> >> -- >> 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 --0015174befce9e9571048fb0b51f Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 103% efficient???=A0 You've solved the world's energy crisis Andy= :-)

BTW, thanks for the class E tips.

73s
Roger G3XBM
On 7 September 2010 20:32, Andy Talbot <andy.g4jnt= @googlemail.com> wrote:
Take a loo= k at G3NYK's Class E design page http://www.alan.melia.btinter= net.co.uk/classepa.htm
=A0
Don't even try biassing the FET with a pot.=A0 You must use a squ= arewave drive- preferrable from a proper MOSFET driver like an ICL7667 or= TC4426 type, or at=A0a push a stack of paralleled 74C drivers will do.=A0=
=A0
I measured somewhere between=A0=A085 - 103% efficiency=A0for a 20 Wat= t design running from 12V on 1.9MHz.=A0 Its very difficult to measure PA= efficiency properly at low frequencies as the HP432=A0 power meter doesn&= #39;t go below 10MHz=A0=A0=A0 Judging by how not-hot the device got, looks= to be around 90%.=A0=A0=A0 See the next RadCom for more details.
=A0
On 7 September 2010 20:08, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:
Stefan/Mal,
=
Clearly my design was not working in class E properly as the PA was di= ssipating a fair amount of heat and it was taking about 0.8A to produce 40= V p-p output from a 13.8V supply which is about half as efficient as it sh= ould be. I took a PA design start from a design program I found on the net= by Tonne Software called "Class E" and the values seemed to be= close to optimum when I adjusted caps and L up and down a small amount,= but the dissipation seems miles off what a good class E design should tak= e. The IRF510 gate voltage is set just below 3V with a resistive pot. The= drive is not a square wave though, so I suppose this could be part of the= issue?

Stefan, if you have a better class E PA circuit for 137kHz suitable fo= r around the 10-20W out region I'd be interested in seeing it. I would= prefer to use toroid inductors because of size. I have several T106-2 cor= es to hand as well as several 16mm diameter 3C90 cores.

I'm still learning..... and not too proud to ask for help from tho= se with more experience.

73s
Roger G3XBM





2010/9/7 Stefan Sch=E4fer <= ;schae= fer@iup.uni-heidelberg.de>
Hello Roger,

Maybe you ca= n send us a circuit with its values. I have built class E PA for 2200/160/= 80/40/30/17/10m and have some experience. If you are using a IRF510 and st= ay in the QRP range (< 10 W) at 137 in a class E stage you wouldn't= even need a heat sink at all if well dimensioned!

See the infos at http://www.classeradio.com/=A0 This is most useful if you are sta= rting with that design. On 137 kHz problems are much smaller than on HF :-= )

Best 73, Stefan/DK7FC

Am 07.09.2010 20:17, schrieb Roger Laptho= rn:=20
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 uW= s.=A0 I need to get some heatsink and more FETs!

Any reports (now less likely) still appreciated.

[Mal - it star= ted out as a Class E design attempt but hadn't been optimised, so I gu= ess this counts as class D. ]

73s
Roger G3XBM



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

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

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 eve= n one cracking. I replaced this with a choke wound on a T106-2 core and ma= de 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 tr= ansformer matching the "in the air" loop.

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

73s
Roger G3XBM


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



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



--
http://g3xbm-qr= p.blogspot.com/
http://www.g3xbm.co.uk
http://www= .youtube.com/user/g3xbm
G3XBM=A0=A0 GQRP 1678=A0=A0=A0 ISWL G11088<= br>




--
http://g3xbm-qrp.blogsp= ot.com/
http:/= /www.g3xbm.co.uk
http://www= .youtube.com/user/g3xbm
G3XBM=A0=A0 GQRP 1678=A0=A0=A0 ISWL G11088<= br> --0015174befce9e9571048fb0b51f--