Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dd02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 339A83800009C; Sat, 15 Dec 2012 17:08:24 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TjzsT-0004aL-Ed for rs_out_1@blacksheep.org; Sat, 15 Dec 2012 22:06:37 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TjzsS-0004aC-Ra for rsgb_lf_group@blacksheep.org; Sat, 15 Dec 2012 22:06:36 +0000 Received: from out1.ip07ir2.opaltelecom.net ([62.24.128.243]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1TjzsQ-0006OJ-JU for rsgb_lf_group@blacksheep.org; Sat, 15 Dec 2012 22:06:35 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgMFADPzzFBcHnFX/2dsb2JhbABFpwMDl0wXc4IZBQEBBQgBAQNJAg8dAQEDBQIBAxEEAQEKJRQBBBoGFggGEwoBAgIBAYdwAxMIsSINiVWLdGmEQwOILIVRhjeCcoobhRGCcw X-IronPort-AV: E=Sophos;i="4.84,291,1355097600"; d="scan'208,217";a="56763266" Received: from host-92-30-113-87.as13285.net (HELO xphd97xgq27nyf) ([92.30.113.87]) by out1.ip07ir2.opaltelecom.net with SMTP; 15 Dec 2012 22:06:13 +0000 Message-ID: <001f01cddb10$64a50b30$0501a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: Date: Sat, 15 Dec 2012 22:06:11 -0000 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: 3.8 (+++) 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: Gary I see you only wind on half the ferrite core whereas I spread the turns symetrically around the whole circumference. In my case I need 8 turns on Prim es 24 on Sec. I first wind the 24 turns around the circumference evenly then the 8 tunrns on top also evenly. This works for me. I wonder if there is any real difference in efficiency [...] Content analysis details: (3.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 3.8 AXB_XMAILER_MIMEOLE_OL_024C2 AXB_XMAILER_MIMEOLE_OL_024C2 X-Scan-Signature: b0c81be0f3328ec24fe2fd5b2fd44f86 Subject: LF: Re: Re: M0BMU mods to the G0MRF PA Content-Type: multipart/alternative; boundary="----=_NextPart_000_001C_01CDDB10.6458BFF0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_40_50,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: 3039ac1d408e50ccf4d81863 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_001C_01CDDB10.6458BFF0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Gary I see you only wind on half the ferrite core whereas I spread the turns = symetrically around the whole circumference. In my case I need 8 turns on Prim es 24 on Sec.=20 I first wind the 24 turns around the circumference evenly then the 8 = tunrns on top also evenly. This works for me. I wonder if there is any real difference in efficiency 73 mal/g3kev ----- Original Message -----=20 From: Gary - G4WGT=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Saturday, December 15, 2012 8:01 PM Subject: LF: Re: M0BMU mods to the G0MRF PA Hi Warren, I have carried out the M0BMU mods to my G0MRF amp. The improvement is = extremely good. Not only does the PA run cool the output is greatly = increased. I have run mine at 600 watts into dummy load during the = initial testing after the mod & up to 400 watts into antenna during = normal Tx. See my web page at :- http://myweb.tiscali.co.uk/wgtaylor/LF%20&%20MF%20Experiments%203.html I hope this will help. 73, Gary - G4WGT. ----- Original Message -----=20 From: Warren Ziegler=20 To: rsgb_lf_group=20 Sent: Saturday, December 15, 2012 4:17 PM Subject: LF: M0BMU mods to the G0MRF PA Hello the list... Since my G0MRF is experiencing intermittent short circuit in = the final amp, I plan on re-doing the output circuit per the M0BMU = modification: http://www.g0mrf.com/images/300w/PA_schematic.jpg The M0BMU mod changes the circuit to a current fed design = which improves the efficiency. The mod calls for a transformer primary = winding using 12 strands of 0.3mm e.c.w. (enamel covered wire).=20 I assume that the 12 strands are used to improve the Q similar to = the way Litz wire works?=20 Has anyone done this mod? Has anyone tried alternatives to = the 12 strands of enamel wire? 73 & tnx Warren K2ORS --=20 73 Warren K2ORS WD2XGJ=20 WD2XSH/23 WE2XEB/2 WE2XGR/1 =20 ------=_NextPart_000_001C_01CDDB10.6458BFF0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Gary
I see you only wind on half the ferrite core = whereas I=20 spread the turns symetrically around the whole = circumference.
In my case I need 8 turns on Prim es 24 on Sec.=20
I first wind the 24 turns around the=20 circumference evenly then the 8 tunrns on top also evenly. This = works for=20 me.
I wonder if there is any real difference in=20 efficiency
 
73 mal/g3kev
 
----- Original Message -----
From:=20 Gary -=20 G4WGT
Sent: Saturday, December 15, = 2012 8:01=20 PM
Subject: LF: Re: M0BMU mods to = the G0MRF=20 PA

Hi Warren,
 
I have carried out the M0BMU mods to = my G0MRF=20 amp. The improvement is extremely good. Not only does the PA run cool = the=20 output is greatly increased. I have run mine at 600 watts into dummy = load=20 during the initial testing after the mod & up to 400 watts into = antenna=20 during normal Tx.
 
See my web page at :-
 
http://myweb.tiscali.co.uk/wgtaylor/LF%20&%20MF%20Experime= nts%203.html
 
I hope this will help.
 
73,
 
Gary - G4WGT.
 
----- Original Message -----
From:=20 Warren = Ziegler=20
To: rsgb_lf_group =
Sent: Saturday, December 15, = 2012 4:17=20 PM
Subject: LF: M0BMU mods to = the G0MRF=20 PA

Hello the list...
       Since my G0MRF is experiencing = intermittent=20 short circuit in the final amp, I plan on re-doing the output = circuit per=20 the M0BMU modification:
http://www.g0m= rf.com/images/300w/PA_schematic.jpg
       The M0BMU mod changes the circuit to = a=20 current fed design which improves the efficiency. The mod calls for = a=20 transformer primary winding using 12 strands of 0.3mm e.c.w. (enamel = covered=20 wire). 
I assume that the 12 strands are used to improve the Q similar = to the=20 way Litz wire works? 
        Has anyone done this mod? Has = anyone tried=20 alternatives to the 12 strands of enamel wire?

   73 & tnx Warren K2ORS


--
73 Warren K2ORS
        =  =20       WD2XGJ
          =  =20     WD2XSH/23
            =  =20   WE2XEB/2
              =  =20 WE2XGR/1

 
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