Return-Path: Received: (qmail 4241 invoked from network); 1 Mar 2005 08:55:45 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore02.plus.net with SMTP; 1 Mar 2005 08:55:45 -0000 Received: from mailnull by ptb-spamcore01.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1D63Bv-0004Qp-2C for g3yxm@wireless.org.uk; Tue, 01 Mar 2005 08:57:21 +0000 Received: from [192.168.67.1] (helo=ptb-mxcore01.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1D63Bu-0004Qm-VI for g3yxm@wireless.org.uk; Tue, 01 Mar 2005 08:57:18 +0000 Received: from mail4.atl.registeredsite.com ([64.224.219.78]) by ptb-mxcore01.plus.net with esmtp (Exim) id 1D63CS-0007Bl-Et for g3yxm@wireless.org.uk; Tue, 01 Mar 2005 08:57:52 +0000 Received: from lwca.org (lwca.org [216.122.11.188]) by mail4.atl.registeredsite.com (8.12.11/8.12.8) with ESMTP id j218opXS018568; Tue, 1 Mar 2005 08:52:58 GMT Received: (from lwca@localhost) by lwca.org (8.9.3/8.9.3) id DAA20501 for lowfer-14416503; Tue, 1 Mar 2005 03:50:52 -0500 (EST) Received: from priv-edtnes28.telusplanet.net (outbound04.telus.net [199.185.220.223]) by lwca.org (8.9.3/8.9.3) with ESMTP id DAA20493 for ; Tue, 1 Mar 2005 03:50:50 -0500 (EST) Received: from cognizant1 ([154.5.20.191]) by priv-edtnes28.telusplanet.net (InterMail vM.6.01.04.00 201-2131-118-20041027) with SMTP id <20050301085013.LMXC3867.priv-edtnes28.telusplanet.net@cognizant1>; Tue, 1 Mar 2005 01:50:13 -0700 Message-ID: <000b01c51e3b$b1aaed40$0201a8c0@private.network> From: "Scott Tilley" To: lowfer@lwca.org, rsgb_lf_group@blacksheep.org Cc: "Steve McDonald" References: <003e01c51e2b$0f93d220$0201a8c0@private.network> Subject: Re: [LW] ... --- ... Date: Tue, 1 Mar 2005 00:50:17 -0800 MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Sender: owner-lowfer@lwca.org Precedence: normal Reply-To: lowfer@lwca.org X-Spam-Filtered: by PlusNet SpamCORE (v3.00) Content-transfer-encoding: 8bit
Seems I was alittle quick to call for help!
 
I found the problem.  When the two 4013 dividers are powered up individually they sinc differently (of course they would!).   Solution: reset one TXs LV PSU until it is in phase or share one PSU!
 
With the TXs running with a conservative 36V supply we get 750W output to the dummy load.
 
I love the smell of burning dummy load in the morning...
 
73 Scott
 
----- Original Message -----
Sent: Monday, February 28, 2005 10:51 PM
Subject: [LW] ... --- ...

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