Return-Path: Received: (qmail 15679 invoked from network); 6 Mar 2000 14:51:53 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by bells.core.plus.net.uk with SMTP; 6 Mar 2000 14:51:53 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12Ryef-0000SQ-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 06 Mar 2000 14:38:41 +0000 Received: from mailhost.netscapeonline.co.uk ([194.200.20.13]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 12Ryee-0000SL-00 for rsgb_lf_group@blacksheep.org; Mon, 06 Mar 2000 14:38:40 +0000 Received: from as32-s16-149-11.cwci.net ([195.44.149.11] helo=netscapeonline.co.uk) by mailhost.netscapeonline.co.uk with esmtp (Exim 3.02 #1) id 12RyeU-0000fV-00 for rsgb_lf_group@blacksheep.org; Mon, 06 Mar 2000 14:38:31 +0000 X-Priority: 3 X-MSMail-Priority: Normal Message-ID: <38C3C29C.6F6952C4@netscapeonline.co.uk> Date: Mon, 06 Mar 2000 14:37:16 +0000 From: "g3kev" X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Organization: Netscape Online member X-Mailer: Mozilla 4.6 [en-gb]C-CCK-MCD NetscapeOnline.co.uk (Win95; I) X-Accept-Language: en-GB,en MIME-Version: 1.0 To: "rsgb" Subject: LF: Ropex Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Hi All. For those suffering from close down in the QRO position when using a grounded antenna loading/matching coil at the base of the antenna, an external LPF in the TX line will cure the problem. I acquired a Ropex recently and on testing into my antenna found this problem and I know other suffer the same. I do not have a cct of the rig otherwise I might be able to do an internal modification to rectify the situation. With the LPF added I can now load the tx into the 50 ohm configured base loaded, grounded inductor at the antenna base. The ARRL antenna h/book has the details for constructing a suitable LPF. I use T200-2 cores and 1200v rated poly capacitors. This LPF will handle up to 1kw of RF and is also suitable for other projects. 73 de Mal/G3KEV