Return-Path: Received: (qmail 21149 invoked from network); 29 Sep 1999 12:36:25 +0100 Received: from unknown (HELO magnet.force9.net) (195.166.128.26) by guiness.force9.net with SMTP; 29 Sep 1999 12:36:25 +0100 Received: (qmail 32630 invoked from network); 29 Sep 1999 11:41:52 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnet.plus.net.uk with SMTP; 29 Sep 1999 11:41:52 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 11WHih-0004tO-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 29 Sep 1999 12:16:23 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from mailserv.cc.kuleuven.ac.be ([134.58.8.44]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 11WHig-0004tJ-00 for rsgb_lf_group@blacksheep.org; Wed, 29 Sep 1999 12:16:22 +0100 Received: from LCBD15.fys.kuleuven.ac.be (LCBD15.fys.kuleuven.ac.be [134.58.80.15]) by mailserv.cc.kuleuven.ac.be (8.9.0/8.9.0) with SMTP id NAA05751 for ; Wed, 29 Sep 1999 13:22:59 +0200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <3.0.1.16.19990929131638.1e37bd9e@mail.cc.kuleuven.ac.be> X-Sender: pb623250@mail.cc.kuleuven.ac.be X-Mailer: Windows Eudora Pro Version 3.0.1 (16) Date: Wed, 29 Sep 1999 13:16:38 To: rsgb_lf_group@blacksheep.org From: "Rik Strobbe" Subject: LF: 136kHz receivers MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: I can confirm Mike's (G3XDV) conclusion that even a simple attenuator can improve the receiving condidtions a lot. Some months ago I took advantage of a slow-CW transmission of G3XDV (with his old VFO that had the very weak 'FSK-trace') to 'optimize' the attenuator value. Using my inverted-L as receiving antenna, with 25dB attenuation the reception of the weak FSK trace was optimal (100% detectable) while with 0dB attenuation the trace could not be seen at all. The RX used was (and is) a Kenwood TS440 direct at 136kHz and with a 500Hz filter. Using the notch and IF-shift I narrowed the bandwidth a bit, allowing sufficient attenuation of DCF39 while receiving slow-CW at 137.7kHz. 73, Rik ON7YD