Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 55CB5380000A3; Tue, 12 Jun 2012 07:16:36 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SeP4A-0007zL-Gm for rs_out_1@blacksheep.org; Tue, 12 Jun 2012 12:15:18 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SeP49-0007zC-Jz for rsgb_lf_group@blacksheep.org; Tue, 12 Jun 2012 12:15:17 +0100 Received: from nm23-vm6.bullet.mail.ird.yahoo.com ([212.82.109.235]) by relay1.thorcom.net with smtp (Exim 4.77) (envelope-from ) id 1SeP45-00076A-LZ for rsgb_lf_group@blacksheep.org; Tue, 12 Jun 2012 12:15:16 +0100 Received: from [77.238.189.54] by nm23.bullet.mail.ird.yahoo.com with NNFMP; 12 Jun 2012 11:15:11 -0000 Received: from [212.82.108.254] by tm7.bullet.mail.ird.yahoo.com with NNFMP; 12 Jun 2012 11:15:11 -0000 Received: from [127.0.0.1] by omp1019.mail.ird.yahoo.com with NNFMP; 12 Jun 2012 11:15:11 -0000 X-DKIM-Result: Domain=yahoo.co.uk Result=Good and Known Domain X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 525915.34323.bm@omp1019.mail.ird.yahoo.com Received: (qmail 79272 invoked by uid 60001); 12 Jun 2012 11:15:11 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s1024; t=1339499711; bh=WwvldZnUcg9DVOmy5D50d9/rqhhA6I9ifC1Kc6/7Ulw=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=2WoDj9ZGymovzc8zOXRfiOLWYQsS0UqPAiVJnfSGsSWkiQSvUvupTxgYcfDfNJVawixjMuJdt6IS6u77QkeTFxMPEypPVAczDygZ8httq0ahg8OlMeehcovYpU2l72BWjpUxt40lce5q4G4WWRiEDVJmhsLBoXDpzYbRyErpEJw= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.co.uk; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=KPR+1dLU7yt8llN04NrrKM1Cb/yBjQSukTmlymRnQ2tmAMxOLbAHeU2R+4UfYOTFdm1brK08oTkyVd4Yhkbn0yFIZOxQE0fbZka55daZrOBT1isaTWL24dzMjmj8N/mFPQPzSPtmPBCpYLj9n2HcrEWt3IoB4OH4HHZB+Q9XdKU=; X-YMail-OSG: 239ePgYVM1ndsNnE9gk6BLw.IAo2z_MCs7a6J1J84hkDiOn AAa1xSzdJDlv16X._Wg_CEUVLB9w_BmXaGhuTUUIt8srtVWTt8Dop_EgMmK8 7ka6Z1Dw6K4OiO0KjSDqA1bBxVq_G3otQo8AZa9Xi5iGUNgHroB4tQZSwC6G Thjw9GKVphz3zDc4Im388pZSwsyYxzx7Obg_6v0SLliPo5Ng2IKs4VkhtmwC hyWS8oyKc9XA0TY41I.xOUJ3wT6wjyp08R_LzlM7IBWOyBksBII7_5eiQ6Ti hjzjXMCKKb4T5fyHcfotafD4XkATlbR46xY5NyMPlD8kJEiPj48KpVLIcXJ6 4pfTb2Oe5mMVvTS1iQRCorYSKVA_3VOAsiBO8MIo5LQnDoF52Hvsj1hieiJX Ax0Wws2YPTJRLPyQiEhAnCR.9gM1WRqo8DDFm..SfKfWz0Fq4xfr6V5TvPA7 DGPkj0obJtbSNAnN2yE.t5Sbn0I40E5rtC2yM.Jejb47i4_Z1m_iMIYrZSMR Nv36S5gTVAEq_.Kb1tvmm4MFMESRE6xefYJbwFMF9fU5ZeXLo2dMY_XiPzsv bkBF66.cNW5WgLj2zkIhiRttPyHYoATy_gpR6H.WQOBNV_bol.yBn63_1TVZ 14ns0knIdZljmRjEO0E7T47k8I6LaE48pT5Wmbq5j85OYfk8p0u_7v4EW2zM C4fa4xD3OFPGU6FN3m3uA8INHWS9owm48R1k6U.9CzFLuSQtO11_9jNtj5LV HWwM- Received: from [86.164.64.131] by web171605.mail.ir2.yahoo.com via HTTP; Tue, 12 Jun 2012 12:15:11 BST X-Mailer: YahooMailWebService/0.8.118.349524 References: <1339438549.67345.YahooMailNeo@web171605.mail.ir2.yahoo.com> <85F124CBD59C48FEB97567F3B69B2AC1@lindavideo> Message-ID: <1339499711.77638.YahooMailNeo@web171605.mail.ir2.yahoo.com> Date: Tue, 12 Jun 2012 12:15:11 +0100 (BST) From: M0FMT To: "rsgb_lf_group@blacksheep.org" In-Reply-To: <85F124CBD59C48FEB97567F3B69B2AC1@lindavideo> MIME-Version: 1.0 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Ken I believe you can operate some thermionic devices in higher classes than C but they generally lack the frequency response of a modern FET. I won't go into figures but just think about it. The high efficiency output stage has to operate like a switch it is not actually an amplifier. The faster it changes state from fully on with ultra low resistance to fully off (which means a device that will operate well into the VHF) the higher the efficiency. If you have a device that is barely rated to say a couple of megs its not going to be much good (in terms of what we are talking about) at 500kc/s. Remember you are trying to get the magnetic field in the inductor to rise and collapse at a very fast rate in-order to generate a high electromagnetic field at the drive frequency. We are not talking sine waves here as a scope on the drain will show. Although a scope on the output side of the drain inductor will show quite a clean looking sine wave. Try it. That chart at the end of that PDF file is very clever and is the guide I use to bring a PA into optimum performance. What I was trying to say is that the math is all very well but if you are trying to make a practical and efficient CW TX for LF then there is enough empirical data from following the guide lines lines shown on the sites I have posted that will get you a good TX. If you want a doctorate in theoretical physics to bamboozle you colleagues then that will detract from the time it takes to build a very interesting high power, efficient TX design well within anybodies capabilities. The GW3UEP design being IMHO a very good (Scalable) example with no RadCom style unobtainium in the components listing. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.82.109.235 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (m0fmt[at]yahoo.co.uk) 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 FSL_FREEMAIL_2 FSL_FREEMAIL_2 0.0 FSL_FREEMAIL_1 FSL_FREEMAIL_1 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: ea184351725c3d278a27e0f764f3f5fd Subject: Re: LF: RE: Class E etc Content-Type: multipart/alternative; boundary="-176341844-148106259-1339499711=:77638" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.3 required=5.0 tests=HTML_50_60, HTML_FONTCOLOR_UNKNOWN,HTML_MESSAGE,TO_ADDRESS_EQ_REAL 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-SCORE: 1:2:494080160:93952408 X-AOL-SCOLL-URL_COUNT: 1 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m411.2 ; domain : yahoo.co.uk DKIM : fail x-aol-sid: 3039ac1d61854fd7251408ca X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ---176341844-148106259-1339499711=:77638 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi Ken=0A=A0=0AI believe you can operate=A0some thermionic devices in highe= r classes than C=A0but they generally lack the frequency response of a mode= rn FET. I won't go into figures but just think about it. The high efficienc= y output stage has to operate like a switch it is not actually an amplifier= . The faster it changes state from fully on with ultra low resistance to fu= lly off (which=A0means a device that will operate=A0well into the=A0VHF)=A0= the higher the efficiency. If you have a device that is barely rated to say= a couple of megs its not going to be much good (in terms of what we are ta= lking about)=A0at 500kc/s. Remember you are trying to get the magnetic fiel= d in the inductor to rise and collapse at a very fast rate in-order to gene= rate a high electromagnetic field at the drive frequency. We are not talkin= g sine waves here as a scope on the drain will show. Although a scope on th= e output side of the drain inductor will show quite a clean looking sine wa= ve. Try it.=0A=A0=0AThat chart at the end of that PDF file is very clever a= nd is the guide=A0I use to bring a PA into optimum performance.=0A=A0=0AWha= t I was trying to say is that the math is all very well but if you are tryi= ng to make a practical and=A0efficient CW TX for LF then=A0there is enough = empirical data from following the guide lines lines shown on the sites I ha= ve posted=A0that will get you a good TX. If you want a doctorate in theoret= ical physics to bamboozle you colleagues then that will detract from the ti= me it takes to build a very interesting high power, efficient=A0TX design w= ell within anybodies capabilities.=A0The GW3UEP design being IMHO a very go= od (Scalable) example with no=A0RadCom=A0style unobtainium in the component= s listing.=0A=0A73 es GL Pete M0FMT IO91UX=0A=0A=0A________________________= ________=0A From: Ken =0ATo: rsgb_lf_group@bla= cksheep.org =0ASent: Monday, 11 June 2012, 22:09=0ASubject: LF: RE: Class E= etc=0A =0A=0A =0AHi Pete. =0AAbout 40 years ago my integration was=0Aquit= e good, liked doing 2nd order differential equations, partial=0Aintegration= and integration by parts, the one thing I had big problems with was=0A3 di= mensional integration of a point in free space . =A0=A0Looking at=0Asome of= the sites my Class C MOSFET PA is probably more like Class E by default.= =0AThe reason I like valves is because they are very forgiving devices unli= ke=0Asemiconductors, also the keep the shack and the cat warm. =0A=A0 =0A73= s =0A=A0 =0AKen =0A=A0 =0AM0KHW =0A=A0 =0A=0A______________________________= __=0A =0AFrom:owner- rsgb_lf_group@blacksheep.org =0A[mailto: owner- rsgb_= lf_group@blacksheep.org ] On Behalf Of M0FMT=0ASent: 11 June 2012 19:16=0AT= o: rsgb_lf_group@blacksheep.org=0ASubject: LF: Class E etc =0A=A0 =0A=A0 = Hi=0AKen =0A=A0 =0AHa=0Aha Stefan, how good is=A0your Integration Ken? = =0A=A0 Here=0Aare a couple of sites that should answer your questions. You= need a good dummy=0Aload and a good oscilloscope. Setting the conditions f= or the amplifier is to do=0Awith=A0 A/ the correct driver preferably using = a FET drive chip (like TC4422=0Anon and TC4421 inverting) that will turn th= e FET fully=A0on and fully off on=0Aeach cycle. Very fast rise time with ac= curate=A0on off timing (mark /=0Aspace). Ensuring the=A0max permitted gate = voltage for the FET=A0is not=0Aexceeded otherwise they pop, look out for tr= ansients, a diode clamp=0Ahelps.=A0 B/ Setting the shunt capacitance and in= ductance=A0in the=0Adrain=A0circuit can be done empirically See=0Aarticle b= elow. Then follow it with=A0a=A0low pass filter, although the=0Aoutput wave= will be surprisingly clean.=A0Calculating the values is difficult as you d= on't necessarily know=0Aall the starting=A0parameters and in any case=A0the= result is=A0going=0Ato wide of the mark. The site below will gives some st= arting values. Best to=0Ause 'Scope measurements to=0Aset the output condit= ions. You are looking for fast, very fast On / Off rise=0Atimes. Gate drive= and understanding the drain circuit is the key. These=0Aamplifiers are ca= pable of incredibly good efficiency well above a dodgy class C=0Aamp. This = means the heat dissipation from the FET is very low at high=0Apower=A0givin= g cool heat-sinks! =0A=A0 The=0AGW3UEP (do a web search) single ended de= sign is capable good efficiency=A0and=0Ahigh power depending upon the FET u= sed and Drain supply voltage. I have=0Amodified one to run reliably at 140w= atts and is capable of almost twice that=0Ainto a dummy load with a heat si= nk that is fairly cool. Adjusting L and C empirically using=0Athe 'scope to= get the correct drain wave shape for max efficiency is the way to=0Ago. Th= e article below shows you what you are looking for. I set my TX up into a= =0A50 Ohm dummy load adjusting L and C to get the correct drain wave shape = on the=0A'scope then measuring the peak voltage across the Dummy load.=A0I = then=0Atransfer my=A0connector from the Dummy load to the input of the tune= d=0Atransformer in the antenna up-lead. I adjust=0Athe coupling link to giv= e the same peak voltage=A0across the tuner link=0Aturns. You are not lookin= g for maximum peak just the sames as across the dummy=0Aload indicating a 5= 0ohm match.=A0This is done by either=A0adding or=0Areducing=A0the number of= turns (about two turns) along with bringing the the=0Atransformer to reson= ance by measuring the peak=A0up-lead current,=0Ahere you are looking for th= e maximum peak.=A0=A0 =0A=A0 =0AOh=0Ayes and WIMA high voltage high value= capacitors from Maplin work well. =0A =0A=A0 Read=0Athe articles and sea= rch info on class E amplifiers.=A0 =0A=A0 =0A=A0 =0AFor=0Asome bed time = reading but ignor the math look at the Tuning Procedure and the=0Apictures = at the end which tell it all really..... http://www.cs.berkeley.edu/~culler= /AIIT/papers/radio/Sokal%20AACD5-poweramps.pdf =0A=A0 =0AFor=0Adesign ide= as http://www.classeradio.com/ =0A=A0 =0AFor=0Aa good practical circuit= for a single ended amp=A0that =A0is a scalable surefire=0Adesign, no need = to reinvent the wheel. =0Ahttp://www.gw3uep.ukfsn.org/ =0A =0A=A0 For=0A= antennas and antenna feed methods a "look no where else site" =0A =0Ahttp= ://www.strobbe.eu/on7yd/136ant/ =0A=A0 =0A73=0Aes GL Pete M0FMT IO91UX = ---176341844-148106259-1339499711=:77638 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hi Ken
=
 
I be= lieve you can operate some thermionic devices in higher = classes than C but they generally lack the frequency response of a mod= ern FET. I won't go into figures but just think about it. Th= e high efficiency output stage = has to operate like a switch it is not actually an amplifier. The faster it= changes state from fully on with ultra low resistance to fully off (which&= nbsp;means a device that will operate well into the VHF) the= higher the efficiency. If you have a device that is barely rated to say a = couple of megs its not going to be much good (in terms of what we are talki= ng about) at 500kc/s. Remember you are trying to get the magnetic field = in the inductor to rise and collapse at a very fast rate in-order to generate a high electromagnetic field at the drive frequency.= We are not talking sine waves here as a scope on the drain will show. Alth= ough a scope on the output side of the drain inductor will show quite a cle= an looking sine wave. Try it.
 
That chart at the end of that PDF file is very clever and is the guide I use to bring a PA = into optimum performance.
 
What I was trying to say is that the math is all very well but if you a= re trying to make a practical and efficient CW TX for LF then the= re is enough empirical data fro= m following the guide lines lines shown on the sites I have posted that= will get you a good TX. If you want a doctorate in theoretical physics to = bamboozle you colleagues then that will detract from the time= it takes to build a very interesting= high power, efficient TX design well within anybodies capabili= ties. The GW3UEP design being IMHO a very good (Scala= ble) example with no RadCom style unobtainium in= the components listing.
 
73 es GL Pete M0FMT IO91UX
From: Ken <ken.h.wright@btinternet.com>
= To: rsgb_lf_group@blacksh= eep.org
Sent: Monday,= 11 June 2012, 22:09
Subject: LF: RE: Class E etc

=0A=0A=0A =0A =0A=0A =0A=0A=0A=0A=0A=0A
=0A=0A
=0A=0A
Hi Pete.
=0A=0A
About 40 years ago my int= egration was=0Aquite good, liked doing 2nd order differential equations, partial=0Aintegrati= on and integration by parts, the one thing I had big problems with was=0A3 = dimensional integration of a point in free space .   Looking at= =0Asome of the sites my Class C MOS= FET PA is probably more like Class E by default.=0AThe reason I like= valves is because they are very forgiving devices unlike=0Asemiconductors,= also the keep the shack and the cat warm.
=0A=0A
&nbs= p;
=0A=0A
73s
=0A=0A
 =
=0A=0A
Ken
=0A=0A
  =0A=0A
M0KHW
=0A=0A
 
=0A=0A
=0A=0A
= = =0A=0A
=0A=0A
= =0A=0A
From:=0A owner- rsgb_lf_group@blacksheep.o= rg =0A[mailto: owner- rsgb_l= f_group@blacksheep.org ]=0AOn Behalf = Of M0FMT
=0ASent: 11 June 2012 19:16
=0ATo: rsgb_lf_group@blacksheep.org
=0ASubject: LF: Class E etc
=0A=0A
= =0A=0A
 
=0A= =0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A<= div id=3D"yiv1450163642">=0A=0A
=0A=0A
=0A= =0A
=0A=0A
 
=0A=0A
=0A=0A=0A=0A
=0A=0A
Hi=0AKen
=0A=0A
=0A=0A
=0A=0A
&nb= sp;
=0A=0A
=0A=0A
=0A=0A
Ha= =0Aha Stefan, how good is = your Integration<= /span>=0AKen?
=0A=0A
=0A=0A
=0A=0A
=  
=0A=0A
=0A=0A=0A=0A
=0A=0A
Here=0Aare a couple o= f sites that should answer your questions. You need a good dummy=0Aload and= a good oscilloscope. Setting the conditions for the amplifier is to do=0Aw= ith  A/ the correct driver preferably using a FET drive chip (like TC4422=0Anon and TC4421 inverti= ng) that will turn the FET f= ully on and fully off on=0Aeach cycle. Very fast rise time with accura= te on off timing (mark /=0Aspace). Ensuring the max permitted gat= e voltage for the FET i= s not=0Aexceeded otherwise they pop, look out for transients, a diode clamp= =0Ahelps.  B/ Setting the shunt capacitance and inductance in the= =0Adrain circuit can be done empirically See=0Aarticle below. Then follow it with a low pass filter, al= though the=0Aoutput wave will be surprisingly=0Aclean. Calculating the values is difficult as you don't necessari= ly know=0Aall the starting parameters and in any case the result = is going=0Ato wide of the mark. The site below will gives some startin= g values. Best to=0Ause 'Scope measurements= to=0Aset the output conditions. You are looking for fast, very fast On / O= ff rise=0Atimes. Gate drive and understanding the drain circuit is the key.=
=0A=0A=
=0A=0A=0A=0A=0A=0A
These=0Aamplifiers are capable of incredibly good effic= iency well above a dodgy class C=0Aamp. This means the heat dissipation fro= m the FET is very low at hig= h=0Apower giving cool heat-sinks!
=0A=0A=0A=0A=0A= =0A
=0A=0A
 
=0A=0A
=0A=0A=0A=0A
=0A=0A
The=0AGW3UEP (do a web search) single ended design is= capable good efficiency and=0Ahigh p= ower depending upon the FET = used and Drain supply voltage. I have=0Amodified one to run reliably at 140= watts and is capable of almost twice that=0Ainto a dummy load with a heat s= ink that is fairly cool. Adjusting L and C empirically using=0Athe 'scope to get the correct drain wave shape for max= efficiency is the way to=0Ago. The article below shows you what you are lo= oking for. I set my TX up into a=0A50 Ohm dummy load adjusting L and C to g= et the correct drain wave shape on the=0A'scope then measuring the peak vol= tage across the Dummy load. I then=0Atransfer my connector from t= he Dummy load to the input of the tuned=0Atransformer in the antenna up-lead. I adjust=0Athe coupling link to give th= e same peak voltage across the tuner link=0Aturns. You are not looking= for maximum peak just the sames as across the dummy=0Aload indicating a 50= ohm match. This is done by either adding or=0Areducing the n= umber of turns (about two turns) along with bringing the the=0Atransformer = to resonance by measuring the peak up-lead current,=0Ahere you are looking for the maximum peak.  
=
=0A=0A=0A=0A
=0A=0A
 <= /div> =0A=0A
=0A=0A
=0A=0A
Oh= =0Ayes and WIMA high voltage= high value capacitors from Maplin<= /span> work well.
=0A=0A
=0A=0A
=0A=0A
 
=0A=0A
=0A=0A=0A=0A
=0A=0A
Rea= d=0Athe articles and search info on class E amplifiers. =
<= div style=3D"background: white;" class=3D"yiv1450163642MsoNormal">
=0A=0A
=0A=0A=0A=0A
 
=0A= =0A
=0A=0A
=0A=0A
 =
=0A=0A
=0A=0A
=0A=0A
For=0Asome bed time reading but ignor the math look at the Tuning Procedure and the=0Apictures at t= he end which tell it all really..... http://www.cs.berkeley.edu/~culler/AIIT/papers/radio/Sokal%2= 0AACD5-poweramps.pdf
=0A=0A
=0A=0A
=0A=0A<= div style=3D"background: white;" class=3D"yiv1450163642MsoNormal"> 
=0A=0A
= =0A=0A
=0A=0AFor=0Adesign ideas
=0A=0A
=0A= =0A=0A=0A
=0A=0A
=0A=0A=0A=0A
=0A=0A
&nb= sp;
=0A=0A
=0A=0A
=0A=0A
For= =0Aa good practical circuit for a single ended amp that  is a scalable surefire=0Adesign, no need to reinve= nt the wheel.
=0A=0A
=0A=0A
=0A=0A
http://www.gw3uep.ukfsn.org/ =0A=0A
=0A=0A
=0A=0A
 
= =0A=0A
=0A=0A= =0A=0A
=0A=0A
For=0Aantennas and antenna feed methods a "look= no where else site"
=0A=0A
=0A=0A=0A=0A
=0A=0A
 
=0A=0A
=0A=0A
=0A=0A
= 73=0Ae= s GL Pete M0FMT IO91UX
=0A=0A
= =0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A= =0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A=
=0A=0A
=0A=0A
=0A=0A=0A


 
<= /div>
---176341844-148106259-1339499711=:77638--