Return-Path: <owner-rsgb_lf_group@blacksheep.org> Received: from rly-de12.mx.aol.com (rly-de12.mail.aol.com [172.19.170.148]) by air-de02.mail.aol.com (v123.4) with ESMTP id MAILINDE023-52049ca56161d4; Wed, 25 Mar 2009 12:04:53 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-de12.mx.aol.com (v123.4) with ESMTP id MAILRELAYINDE127-52049ca56161d4; Wed, 25 Mar 2009 12:04:40 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1LmVaE-0000j0-Sv for rs_out_1@blacksheep.org; Wed, 25 Mar 2009 16:04:02 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1LmVaE-0000ir-GO for rsgb_lf_group@blacksheep.org; Wed, 25 Mar 2009 16:04:02 +0000 Received: from mk-filter-4-a-1.mail.uk.tiscali.com ([212.74.100.55]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from <g4wgt@tiscali.co.uk>) id 1LmVaC-0005Kj-8l for rsgb_lf_group@blacksheep.org; Wed, 25 Mar 2009 16:04:02 +0000 X-Trace: 168652841/mk-filter-4.mail.uk.tiscali.com/B2C/$b2c-THROTTLED-DYNAMIC/b2c-CUSTOMER-DYNAMIC-IP/88.106.79.140/None/g4wgt@tiscali.co.uk X-SBRS: None X-RemoteIP: 88.106.79.140 X-IP-MAIL-FROM: g4wgt@tiscali.co.uk X-MUA: Microsoft Office Outlook 11Produced By Microsoft MimeOLE V6.00.2900.3350 X-IP-BHB: Once X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AsYEAFfyyUlYak+M/2dsb2JhbACDJ0OGPoNrxFIHg24G X-IronPort-AV: E=Sophos;i="4.38,419,1233532800"; d="scan'208";a="168652841" Received: from 88-106-79-140.dynamic.dsl.as9105.com (HELO asus) ([88.106.79.140]) by smtp.tiscali.co.uk with ESMTP; 25 Mar 2009 16:03:58 +0000 From: "Gary - G4WGT" <g4wgt@tiscali.co.uk> To: <rsgb_lf_group@blacksheep.org> References: <BE4A5829B4DB4F54ACE6C6FD0AA72DCF@gmc.net> <86B4F549F8F247DDA470143B3BE77364@Hugh> Date: Wed, 25 Mar 2009 16:03:58 -0000 Message-ID: <008c01c9ad63$4e9a9190$6401a8c0@asus> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 In-Reply-To: <86B4F549F8F247DDA470143B3BE77364@Hugh> Thread-Index: AcmtWxCqHzXqqxfPR2ShD6cf3pvn0AAB5ugg X-Karma: unknown: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: RE: Re: TDA2003, TDA2030 for PA? Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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 X-AOL-IP: 193.82.116.20 Hi Petr, I have tested a TDA2030 for a 500KHz driver & is OK for 136KHz as other authors have stated. It does fall off very rapidly from 200KHz & higher & is of no use at 500KHz. 73 Gary - G4WGT. -----Original Message----- From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Hugh_m0wye Sent: 25 March 2009 15:01 To: rsgb_lf_group@blacksheep.org Subject: LF: Re: TDA2003, TDA2030 for PA? I successfully made a TDA2030 amplifier which i used for all my intial=20 experimenting on 137kHz Photo http://www.m0wye.radiouk.com/lfamp.jpg The data sheet for this IC claims a bandwidth of 140kHz so it won't work on=20 500kHz. I think I got about 6Watts out. Not all the audio ICs have as much bandwidth as this. You need a matching circuit on the output to convert the low impedance of=20 the amp to 50 ohms - or whatever your antenna system uses. 73 Hugh M0WYE ----- Original Message -----=20 From: "Petr Mal=FD" <p.maly@gmc.net> To: <rsgb_lf_group@blacksheep.org> Sent: Wednesday, March 25, 2009 1:38 PM Subject: LF: TDA2003, TDA2030 for PA? Hi all, My intention is to build a small transmitter up to some 10W for 136 and 505=20 kHz, this time not the D class, but B or AB class. I think of employing AF amplifiers such as TDA2003, TDA2030, or similar. Of=20 course, mainly 505 kHz is rather out of range so that nothing is guaranteed. This is why I ask before experimenting. Did anybody try to use these for 136/505 kHz? Tks, 73, Petr, OK!FIG http://ok1fig.nagano.cz