Return-Path: X-Spam-DCC: paranoid 1290; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_50_60,HTML_MESSAGE,RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tB8BBTbD032638 for ; Tue, 8 Dec 2015 12:11:29 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a6G7b-000559-5E for rs_out_1@blacksheep.org; Tue, 08 Dec 2015 11:07:51 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a6G7a-00054w-HH for rsgb_lf_group@blacksheep.org; Tue, 08 Dec 2015 11:07:50 +0000 Received: from smtpout.karoo.kcom.com ([212.50.160.34]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1a6G6d-0000O1-EZ for rsgb_lf_group@blacksheep.org; Tue, 08 Dec 2015 11:07:49 +0000 X-IronPort-AV: E=Sophos;i="5.20,399,1444690800"; d="scan'208,217";a="147113307" Received: from unknown (HELO [127.0.0.1]) ([82.153.108.248]) by smtpout.karoo.kcom.com with ESMTP; 08 Dec 2015 11:06:35 +0000 Message-ID: <5666B9BA.3050707@lineone.net> Date: Tue, 08 Dec 2015 11:06:34 +0000 From: LineOne User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <579355A36AEE9D4FA555C45D556003AB1B2C74D0@servigilant.vigilant.local> In-Reply-To: <579355A36AEE9D4FA555C45D556003AB1B2C74D0@servigilant.vigilant.local> X-Scan-Signature: ebba021850e0a5d4120636e52401e975 Subject: Re: LF: TDA7498 2x100W audio PA for LF use ?? Content-Type: multipart/alternative; boundary="------------010204020105000204000102" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 5658 This is a multi-part message in MIME format. --------------010204020105000204000102 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit I bought a 300W amplifier kit, all the small transistors have an "ft" in the VHF region and the power transistors ft is 15MHz. Small modifications include changing the Zobel network and bypassing some electrolytics with 100nF. Latterly I have fitted 250V power transistors to replace the 150V, some spikes were liable to "kill" the originals. It gives me 300W dc input, about half available as RF power. Forced cooling is necessary. On 08/12/2015 09:41, VIGILANT Luis Fernández wrote: > Hi LF > > I have read about using old TDA2010 audio modules as exciter stages > for LF amplifiers > > Searching the web have found that there is actually a bunch of cheap > audio amplifiers based > in TDA7498 which is 2x100W. I wonder if this worths to get some watts > into LF. Mat be the > two outputs can be also combined if feeded ati phase ? > > Have a look at one of this here > http://www.ebay.com/itm/New-TDA7498-100W-100W-Class-D-Amplifier-Board-Computer-Amplifier-/310956174740?hash=item48666ead94:g:WXcAAOxyYANTcIW4 > > 73 de Luis > EA5DOM --------------010204020105000204000102 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 8bit I bought a 300W amplifier kit, all the small transistors have an "ft" in the VHF region and the power transistors ft is 15MHz. Small modifications include changing the Zobel network and bypassing some electrolytics with 100nF. Latterly I have fitted 250V power transistors to replace the 150V, some spikes were liable to "kill" the originals.
It gives me 300W dc input, about half available as RF power. Forced cooling is necessary.


On 08/12/2015 09:41, VIGILANT Luis Fernández wrote:
Hi LF

I have read about using old TDA2010 audio modules as exciter stages for LF amplifiers

Searching the web have found that there is actually a bunch of cheap audio amplifiers based
in TDA7498 which is 2x100W. I wonder if this worths to get some watts into LF. Mat be the
two outputs can be also combined if feeded ati phase ?

Have a look at one of this here

73 de Luis
EA5DOM

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