Return-Path: X-Spam-DCC: paranoid 1182; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, RATWARE_GECKO_BUILD,SPF_PASS autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u7QBp1VE026996 for ; Fri, 26 Aug 2016 13:51:01 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1bdFag-0005Nq-JW for rs_out_1@blacksheep.org; Fri, 26 Aug 2016 12:46:30 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1bdFaf-0005Nh-4t for rsgb_lf_group@blacksheep.org; Fri, 26 Aug 2016 12:46:29 +0100 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1bdFac-0005kq-VB for rsgb_lf_group@blacksheep.org; Fri, 26 Aug 2016 12:46:27 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 58B20209D3 for ; Fri, 26 Aug 2016 13:46:25 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3sLK4x02gzzyPp for ; Fri, 26 Aug 2016 13:46:24 +0200 (CEST) Message-ID: <57C02C0F.1070706@posteo.de> Date: Fri, 26 Aug 2016 13:46:23 +0200 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <579355A36AEE9D4FA555C45D556003AB5D7D1BA1@servigilant.vigilant.local> In-Reply-To: <579355A36AEE9D4FA555C45D556003AB5D7D1BA1@servigilant.vigilant.local> X-Scan-Signature: 59677119386dcf9f1872cb454dc1331d Subject: LF: A simple ULF/MF diplexer? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.11 Status: RO X-Status: X-Keywords: X-UID: 8632 Hi all, I would like to run some transmissions on MF WSPR but i also like to run a longer transmission on 2.97 kHz. In the current ULF TX installation i'm using a parallel 2 nF capacitor anyway. This is just -j167 Ohm on MF. I could series compensate it with 65 uH (which is just j1.2 Ohm at 2970 Hz :-) ) to ground. The 65 uH could be parallel compensated for MF, using 280 nF. Then i could add a ferrite transformer to apply the MF RF across the 65uH/280nF parallel circuit. The large loading coil of 1.3 H will be a high impedance, hopefully, as long as there is no internal resonance on MF due to its own winding capacity. The 2 nF capacitor will have to handle the sum current of ULF and MF. QRO is not possible on MF i think but it will handle a few watts which is fine for WSPR. Hmm, worth a try? 73, Stefan