Return-Path: Received: from mtain-mi10.r1000.mx.aol.com (mtain-mi10.r1000.mail.aol.com [172.21.131.168]) by air-me10.mail.aol.com (v128.3) with ESMTP id MAILINME101-8bc44bd5f8351ef; Mon, 26 Apr 2010 16:31:49 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mi10.r1000.mx.aol.com (Internet Inbound) with ESMTP id F17B9380001FD; Mon, 26 Apr 2010 16:31:46 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1O6UxC-0002P9-FH for rs_out_1@blacksheep.org; Mon, 26 Apr 2010 21:30:54 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1O6UxB-0002P0-K5 for rsgb_lf_group@blacksheep.org; Mon, 26 Apr 2010 21:30:53 +0100 Received: from smtp-out30.alice.it ([85.33.2.30]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1O6Ux8-0000ig-Rz for rsgb_lf_group@blacksheep.org; Mon, 26 Apr 2010 21:30:53 +0100 Received: from FBCMMO04.fbc.local ([192.168.184.135]) by smtp-out30.alice.it with Microsoft SMTPSVC(6.0.3790.3959); Mon, 26 Apr 2010 22:21:50 +0200 Received: from FBCMCL01B04.fbc.local ([192.168.69.85]) by FBCMMO04.fbc.local with Microsoft SMTPSVC(6.0.3790.3959); Mon, 26 Apr 2010 22:20:37 +0200 Received: from PCCasa ([82.59.154.93]) by FBCMCL01B04.fbc.local with Microsoft SMTPSVC(6.0.3790.3959); Mon, 26 Apr 2010 22:20:35 +0200 Message-ID: <9829633692A44A4192719E9765900369@PCCasa> From: "Daniele Tincani" To: References: <4EB4F8217FCC42CAB07AE666A6AB07B8@AGB> <4BD5EB5E.6070702@telia.com> In-Reply-To: <4BD5EB5E.6070702@telia.com> Date: Mon, 26 Apr 2010 22:19:19 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18005 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18005 X-OriginalArrivalTime: 26 Apr 2010 20:20:35.0181 (UTC) FILETIME=[ED8109D0:01CAE57D] X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Probably not a new question... Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original 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=0.1 required=5.0 tests=MISSING_OUTLOOK_NAME 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 x-aol-global-disposition: G x-aol-sid: 3039400cded24bd5f8325920 X-AOL-IP: 193.82.116.20 I experienced building a softrock for 40m months ago, very interesting (and cheap :-)) Anyway I don't think a softrock-style SDR would fit the requirements, it is by far too simple to compete with a "real" radio in my humble opinion. In addition to this, performance requirements then move from the radio front-end to the audio card, which is not exactly what I mean when I think of a receiver... Cheers D. ----- Original Message ----- From: "Johan H. Bodin" To: Sent: Monday, April 26, 2010 9:37 PM Subject: Re: LF: Probably not a new question... > Yes, or building a simple "SoftRock style" direct conversion front end > and feed the audio to the soundcard for further processing by Winrad or > similar software capable of processing I/Q audio. What you need is some > kind of preselection filer, a quadrature mixer (half-complex mixer, > "Tayloe mixer") and a pair of good audio preamps. The front end LO can > be as simple as an XTAL oscillator followed by a 74HC74 that divides the > XTAL frequency by 4 and produces the two 0/90 degree clocks needed by > the mixer. A 74HC4052 analog switch works quite well as mixer on LF, > this one can be clocked by the 'HC74 mentioned above or any other 2-bit > synchronous binary counter clocked by fLO*4. The tuning is done in the > software. > > You can find some ideas at > > http://yu1lm.qrpradio.com > > or look at Gerald Youngblood's QEX article series "A Software Defined > Radio for the masses" > > http://www.flex-radio.com/News.aspx?topic=publications > > 73 de Johan SM6LKM > > Graham skrev 2010-04-26 20:55: >> You may be better building a LF convertor ? >> >> G .. >> >> *From:* Daniele Tincani >> *Sent:* Monday, April 26, 2010 6:23 PM >> *To:* rsgb_lf_group@blacksheep.org >> *Subject:* LF: Probably not a new question... >> >> Hi LF, >> among the so-called "communications receivers" (0.1-30MHz, all modes, >> well-known brands, etc.) in the "< 300 euros" price range (used, of >> course :-)), which models have good characteristics at LF frequencies? >> Any recommended models (in the same price range) outside of the "comms >> receivers" class? >> Many thanks for your feedbacks. >> Cheers >> D. >> >> >> > -------------------------------------------------------------------------------- Nessun virus nel messaggio in arrivo. 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