Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg01.r1000.mx.aol.com (Internet Inbound) with ESMTP id D6DBD38000091; Sat, 7 Jul 2012 15:30:29 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SnaAG-0001ci-JO for rs_out_1@blacksheep.org; Sat, 07 Jul 2012 19:55:32 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SnaAF-0001cZ-Vi for rsgb_lf_group@blacksheep.org; Sat, 07 Jul 2012 19:55:31 +0100 Received: from nm23-vm5.bullet.mail.ird.yahoo.com ([212.82.109.234]) by relay1.thorcom.net with smtp (Exim 4.77) (envelope-from ) id 1SnaAD-0000hw-Fd for rsgb_lf_group@blacksheep.org; Sat, 07 Jul 2012 19:55:30 +0100 Received: from [77.238.189.232] by nm23.bullet.mail.ird.yahoo.com with NNFMP; 07 Jul 2012 18:55:28 -0000 Received: from [212.82.108.224] by tm13.bullet.mail.ird.yahoo.com with NNFMP; 07 Jul 2012 18:55:28 -0000 Received: from [127.0.0.1] by omp1001.bt.mail.ird.yahoo.com with NNFMP; 07 Jul 2012 18:55:28 -0000 X-DKIM-Result: Domain=btopenworld.com Result=Signature OK X-Yahoo-Newman-Id: 279960.2637.bm@omp1001.bt.mail.ird.yahoo.com Received: (qmail 56052 invoked from network); 7 Jul 2012 18:55:28 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btopenworld.com; h=DKIM-Signature:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Received:Message-ID:From:To:References:In-Reply-To:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=shZFlzROdtIgNBCZfnAmOaAhoT6YcpPwNndSRvxOeF2a8ZJXnLrn3aaQ5dT8zFxzGXisSzRN9qECiO98XB4PT4SPioKRvlclxLxlj25Vaz4LAS2+9guhFiKLtLMEIAFQv58XSJ6AdZaaHL7oiGYlg+QN1LNeFHLEVAT/V6khKxA= ; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btopenworld.com; s=s1024; t=1341687328; bh=tx4BIK1qejJ3ouNQOVPR4lVLJ3005ZaLn21WY9tfsy0=; h=X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Received:Message-ID:From:To:References:In-Reply-To:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=u5zMVbmJt+ulJYOo2cv+cNObZduGVvLTwvsP73ma58m/U99g2rdhTmSUgd5CFDF3Wxz9oW1Aq3GOW+q0r75ssEUw8V2Ob8WAyJWjbzoRFgkrJ2TcknagEdDBP3+hkGn3Uo2lXWH7sLDQQbe1A3+h0x5I62g4y3DQFmQxWhEp+Dk= X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: 28kuolAVM1mG5SUPW1Tr4GOKt.VQmowIcJKoV8F9YpLhcLH yOen1nH5gvZtS30xqbFhlr7DC59rrpgmR1gPDDcuwHBrBcSKvxgbFD4QfRbP diHKzewEhOdZMwiE4wzd_aEqD729zcebEDSXnshNRc7EZiIUhyoPsalFhRmm WF7yuvIq6d0NGz6Im4SCxON7X5_.A.rHQApK2cb7bKcr9PYdSssxbrr6X20C YFQPkWLnh1NUfE4ChOGfO_I6A2DqT6.1_XtzJzxDo_tOIj3DTYJsAQGKZtit 6A8XwpP4LALUlgNfsAi5dxhwT0dWTujkTlxUKCZn7BBTatvFH2_u1S7xk6Il acZHxvCvbZbBPZRn1bLZkgB.br86FLuSQ__.OwIW8.B5v4vZSbUCV2wDaK9v 4hOJtn3w0HrLksEI1qiFnmdW3RF2P9Kb2hEWrjN53XG_Q X-Yahoo-SMTP: Cxhli3eswBD1ozmtAojhjrja86kWx0Qm9tycD5QR1DKWrOLgjJcXkw-- Received: from JimPC (james.moritz@86.185.202.35 with login) by smtp819.mail.ird.yahoo.com with SMTP; 07 Jul 2012 18:55:28 +0000 GMT Message-ID: <804F85B8E2764C8C9D9007462F586A67@JimPC> From: "James Moritz" To: References: <7E7DFBB4D102A04DB5ADC88D66628A4A0FAB99CC@ICTS-S-MBX5.luna.kuleuven.be> <1SmrFA-199XcW0@fwd21.t-online.de> <4FF5EB68.9040507@iup.uni-heidelberg.de> <4FF61402.6000703@iup.uni-heidelberg.de> <4FF6EE70.2040600@iup.uni-heidelberg.de> In-Reply-To: <4FF6EE70.2040600@iup.uni-heidelberg.de> Date: Sat, 7 Jul 2012 19:55:37 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18197 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18463 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Dear Stefan, LF Group, > One more question: Currently i use the BF862 since it was on hand. However > i could use a normal BF245 instead. I thought it could have an advantage > since the housing is bigger and so the temperature differences should be > smaller. Also the BF862 has a relative high Id, so the power dissipation > and hence the temperatures may be higher. Vdd=5V and the osc didn't start > to oscillate when using a source resistor of 100 Ohm. When using 50 Ohm > then it runs and the DC source voltage is 0.4V, i.e. 8 mA DC drain > current. Could be a bit lower. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.82.109.234 listed in list.dnswl.org] 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines X-Scan-Signature: c1f72e5acb1277e013f90c915ad7ad68 Subject: Re: LF: RE: Analog oscillators Content-Type: text/plain; format=flowed; charset="ISO-8859-15"; reply-type=response 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-SCOLL-SCORE: 0:2:445169664:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d300.1 ; domain : btopenworld.com DKIM : pass x-aol-sid: 3039ac1d60c94ff88e551859 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Dear Stefan, LF Group, > One more question: Currently i use the BF862 since it was on hand. However > i could use a normal BF245 instead. I thought it could have an advantage > since the housing is bigger and so the temperature differences should be > smaller. Also the BF862 has a relative high Id, so the power dissipation > and hence the temperatures may be higher. Vdd=5V and the osc didn't start > to oscillate when using a source resistor of 100 Ohm. When using 50 Ohm > then it runs and the DC source voltage is 0.4V, i.e. 8 mA DC drain > current. Could be a bit lower. When you replace the existing inductor with a high-Q one, you will find that the loop gain of the circuit is increased due to the higher Q, and you will be able to use a lower gain/reduced transistor bias current. For CW enthusiasts, I am suprised more use is not made of simple LC VFOs. A drift of +/- 100Hz during the time taken for a QSO is usually not noticeable, and it is easy to achieve this in the LF/MF range. Also, the narrow tuning range means an elaborate tuning mechanism with reduction gearing is not needed - just a knob with a simple hand-marked scale is adequate. It is much simpler than the schemes needed to obtain an LF/MF signal by dividing/mixing down the output of an HF rig, etc. A VFO is also a much better practical choice than a crystal oscillator, which leaves you stuck on a fixed frequency. Cheers, Jim Moritz 73 de M0BMU