Return-Path: Received: (qmail 5754 invoked from network); 1 Mar 2005 10:50:40 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore04.plus.net with SMTP; 1 Mar 2005 10:50:40 -0000 Received: from mailnull by ptb-spamcore01.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1D64z4-000BJn-MC for dave@picks.force9.co.uk; Tue, 01 Mar 2005 10:52:14 +0000 Received: from [192.168.67.1] (helo=ptb-mxcore01.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1D64z2-000BIP-6n for dave@picks.force9.co.uk; Tue, 01 Mar 2005 10:52:08 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (Exim) id 1D64zZ-0005yo-D0 for dave@picks.force9.co.uk; Tue, 01 Mar 2005 10:52:41 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1D64wm-0000Fx-Ft for rs_out_1@blacksheep.org; Tue, 01 Mar 2005 10:49:48 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1D64wk-0000EP-2X for rsgb_lf_group@blacksheep.org; Tue, 01 Mar 2005 10:49:46 +0000 Received: from smtp800.mail.ukl.yahoo.com ([217.12.12.142]) by relay.thorcom.net with smtp (Exim 4.43) id 1D64wg-0000Y6-Vp for rsgb_lf_group@blacksheep.org; Tue, 01 Mar 2005 10:49:45 +0000 Received: from unknown (HELO Main) (Alan.Melia@213.122.25.33 with login) by smtp800.mail.ukl.yahoo.com with SMTP; 1 Mar 2005 10:49:36 -0000 Message-ID: <001c01c51e4c$569cedc0$6507a8c0@Main> From: "Alan Melia" To: rsgb_lf_group@blacksheep.org References: <003e01c51e2b$0f93d220$0201a8c0@private.network> Date: Tue, 1 Mar 2005 10:49:21 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 X-SPF-Result: relay.thorcom.net: 217.12.12.142 is neither permitted nor denied by domain of btinternet.com X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=failed,none Subject: LF: Re: ... --- ... Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.1 required=5.0 tests=MAILTO_TO_SPAM_ADDR 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-Spam-Filtered: by PlusNet SpamCORE (v3.00) Hi Steve I have just had a thought your construction looks fine....BUT maybe the two coils are too close together and there is some coupling. I wonder if it is possible to temporarily turn one at right angles to kill any coupling and see if that helps?? The biggies in my Web page were made with big toroids I believe probably iron dust rather than ferrite, as the inductance reqquired is not that high Cheers de Alan G3NYK ----- Original Message ----- From: "Scott Tilley" To: ; Sent: 01 March 2005 06:51 Subject: LF: ... --- ... The smoke test of this Wilkinson Combiner was successfull in that no smoke came out and nothing died. However, we get enough heat to cook an egg on the 100ohm balance resistor. We have a scope match on the output to the dummy load and it shows about 225W from one transmitter, add another and we get 450W, success NOPE! The transmitters are outputting ~450W each! Therefore, half the power is being absorbed in the 100ohm balance resistor. Examining the phase relationship of the input to the combiner waveforms indicates they are in phase within ~10degrees and almost equal in amplitude. So what gives! Anyone have some idea what may be going wrong? Of course we have checked and doubled checked the circuit for errors and nothing... All seems as it should according to formulas and drawings we have viewed and designed it from. Does anyone have an idea how we could troubleshoot our way through this? Any advice would be appreciated. 73 Scott and Steve(It's all his fault ;-) Check the status of radio beacon 'TIL' in CN89lg at: www.scottboxx.com/radio