Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w5B9XrbB007669 for ; Mon, 11 Jun 2018 11:33:55 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1fSJ9L-0000zD-BW for rs_out_1@blacksheep.org; Mon, 11 Jun 2018 10:30:07 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1fSJ9L-0000z2-1h for rsgb_lf_group@blacksheep.org; Mon, 11 Jun 2018 10:30:07 +0100 Received: from mout01.posteo.de ([185.67.36.65]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1fSJ9J-0004Cp-FS for rsgb_lf_group@blacksheep.org; Mon, 11 Jun 2018 10:30:05 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout01.posteo.de (Postfix) with ESMTPS id 2A3AA20E33 for ; Mon, 11 Jun 2018 11:30:01 +0200 (CEST) X-DKIM-Result: Domain=posteo.de Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1528709404; bh=4emaGkSbj27Vr0NMNDpllvxB33KvYplNXlPXEyWIruc=; h=Date:From:To:Subject:From; b=LtSfZtyXbBcmbfSIcjmVvttMErhBpzDF0wI4Io/52GJ6csw8aSJV5TpWudIooYfHw 4cfAd92zf6qAJtINnHrvu+5S+TmSR4T0tINUqid9aEE+EmWH4OFPklheSC1h8pMoJl vKbkkMMZJIUfU4S6WyoJE7JNsN8h7LhuP/fJWt3iF7XIfVLTHhxxV7fa8ggjxMTA5/ +syGfKC4/WqeVlL/5wPlzN25a35p1QGmdZHfXWuv+FU8Z0uQ2GqnsIwlmRjXCH5H/G wRnB3b8HVd9JudBnEXYYNbLIKKVl3EmWZGisqMN1VfYgFpPcEsCdCPTNzNOhhN/xgp rqE9xBkEcnZrA== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 41475b5SGnz9s0x for ; Mon, 11 Jun 2018 11:29:54 +0200 (CEST) Message-ID: <5B1E4111.4020501@posteo.de> Date: Mon, 11 Jun 2018 11:29:53 +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: <5B1B994F.7020509@posteo.de> In-Reply-To: X-Spam-Score: -2.3 (--) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: Hello Juan, Am 09.06.2018 16:11, schrieb TG9AJR Juan Munoz: > My station is an Elecraft K3 and also a FlexRadio 6600 which whom I am > doing this receptions, antenna just my 40m dipole to begin with maybe > later I can read and learn more about an receiving antenna for LF/MF > but for now is a good start for me. A dipole can be a fine antenna but it depends on the way you couple it to the RX input. If you use certain types of baluns it can act as a shortcut on that frequency. But if your dipole is just two wires connected to coax or ladder line then it may work. Anyway, most likely you will need a preamp. But, if you don't have a preamp and/or don't know how to build, there is still some way for improvements: Use your ferrite rod or core and build a selective matching. A primary turn of some ten turns (maybe up 100) connected to a separate clean ground/earth (a rod in the garden, not the earth from the shack!). The other end is connected to the dipole including its feeder line (coax). So it will be a T antenna. Use a small variable C in parallel to tune for resonance at 475 kHz. Then add a secondary winding to feed the RX. Here, you may just need 10 turns or so. You will need some testing... And you should see a higher noise level when tuning to resonance. [...] Content analysis details: (-2.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [185.67.36.65 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 7001055fa59a9c23b9831ea6d317a074 Subject: Re: LF: My first 630m WSPR Content-Type: text/plain; charset=UTF-8; format=flowed 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 Hello Juan, Am 09.06.2018 16:11, schrieb TG9AJR Juan Munoz: > My station is an Elecraft K3 and also a FlexRadio 6600 which whom I am > doing this receptions, antenna just my 40m dipole to begin with maybe > later I can read and learn more about an receiving antenna for LF/MF > but for now is a good start for me. A dipole can be a fine antenna but it depends on the way you couple it to the RX input. If you use certain types of baluns it can act as a shortcut on that frequency. But if your dipole is just two wires connected to coax or ladder line then it may work. Anyway, most likely you will need a preamp. But, if you don't have a preamp and/or don't know how to build, there is still some way for improvements: Use your ferrite rod or core and build a selective matching. A primary turn of some ten turns (maybe up 100) connected to a separate clean ground/earth (a rod in the garden, not the earth from the shack!). The other end is connected to the dipole including its feeder line (coax). So it will be a T antenna. Use a small variable C in parallel to tune for resonance at 475 kHz. Then add a secondary winding to feed the RX. Here, you may just need 10 turns or so. You will need some testing... And you should see a higher noise level when tuning to resonance. In any way you should see the QRN bursts in your spectrogram. At night it will be heavy. If not, then your antenna signal is to weak. WA4SZE may be a good test signal... 73, GL, Stefan PS: Or try a tuned loop instead. This works also very well, even better i would say.