X-GM-THRID: 1206336456430977085 X-Gmail-Labels: rsgb lf X-Gmail-Received: 96909ba0be00a84ee81426c5ca3e9ee67562d3eb Delivered-To: daveyxm@gmail.com Received: by 10.54.127.17 with SMTP id z17cs5104wrc; Fri, 16 Jun 2006 03:01:35 -0700 (PDT) Received: by 10.78.21.7 with SMTP id 7mr944473huu; Fri, 16 Jun 2006 03:01:35 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.gmail.com with ESMTP id 2si625973huc.2006.06.16.03.01.34; Fri, 16 Jun 2006 03:01:35 -0700 (PDT) Received-SPF: neutral (gmail.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1FrB3I-0005Mo-GQ for rs_out_1@blacksheep.org; Fri, 16 Jun 2006 10:55:44 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1FrB3H-0005Mf-MM for rsgb_lf_group@blacksheep.org; Fri, 16 Jun 2006 10:55:43 +0100 Received: from grunt2.ihug.co.nz ([203.109.254.42]) by relay1.thorcom.net with esmtp (Exim 4.62) (envelope-from ) id 1FrB3D-00070y-Qj for rsgb_lf_group@blacksheep.org; Fri, 16 Jun 2006 10:55:43 +0100 Received: from 203-109-182-194.dialup.ihug.co.nz (cobaltxp) [203.109.182.194] by grunt2.ihug.co.nz with smtp (Exim 3.35 #1 (Debian)) id 1FrB34-00065R-00; Fri, 16 Jun 2006 21:55:31 +1200 Message-ID: <000e01c6912b$003878c0$c2b66dcb@cobaltxp> From: "Murray ZL1BPU" To: References: <44894231.30866.D42969@localhost><00b601c68baa$e8cf78d0$26180d54@traceydlqceh0p> <44894CF9.4080102@usa.net><4491E6FB.2020705@usa.net> <20060616022030.coqaz7zeo7y8wgw8@webmail.versatel.de> <002101c6910f$d5868e20$0300a8c0@LAPTOP> Date: Fri, 16 Jun 2006 21:55:28 +1200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Spam-Score: -0.1 (/) X-Spam-Report: autolearn=disabled,AWL=-0.115 Subject: LF: Re: Re: PAs Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none 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 Status: O X-Status: X-Keywords: X-UID: 5286 Uwe, It certainly looks like 2nd harmonic problems to me too, probably linearity (gain) imbalance. Another thing you will have discovered is that with the harmonic information Peter mentioned, the SWR meter or bridge (if you use one) won't give good nulls, because the harmonic content won't be matched at the antenna tuner. Either you need a rather better low pass filter, or to sort out the non-linearity. My LF TX operates in Class D (can't get more nonlinear than that) but the waveform is nicely sinusoidal at the antenna. Mind you, third harmonic is my problem, not second. 73, Murray ZL1BPU