Return-Path: X-Spam-DCC: paranoid 1102; 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=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, 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 tB9JZ6hs004593 for ; Wed, 9 Dec 2015 20:35:06 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a6kQO-0005aw-9F for rs_out_1@blacksheep.org; Wed, 09 Dec 2015 19:29:16 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a6kQN-0005ah-Lj for rsgb_lf_group@blacksheep.org; Wed, 09 Dec 2015 19:29:15 +0000 Received: from smtpout.karoo.kcom.com ([212.50.160.34]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1a6kPJ-0006b6-8u for rsgb_lf_group@blacksheep.org; Wed, 09 Dec 2015 19:29:14 +0000 X-IronPort-AV: E=Sophos;i="5.20,405,1444690800"; d="scan'208,217";a="83924450" Received: from unknown (HELO [127.0.0.1]) ([82.153.108.248]) by smtpout.karoo.kcom.com with ESMTP; 09 Dec 2015 19:27:54 +0000 Message-ID: <566880B7.9010908@lineone.net> Date: Wed, 09 Dec 2015 19:27:51 +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: <579355A36AEE9D4FA555C45D556003AB1B2C8409@servigilant.vigilant.local> In-Reply-To: <579355A36AEE9D4FA555C45D556003AB1B2C8409@servigilant.vigilant.local> X-Scan-Signature: 3547ef0bd9aa4f6a2596c8a6b1b20265 Subject: Re: LF: TDA7498 2x100W audio PA for LF use ?? Content-Type: multipart/alternative; boundary="------------070004000708080305000402" 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: 5688 This is a multi-part message in MIME format. --------------070004000708080305000402 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit It comes from HongKong via Ebay usually as a kit but also ready-built for only a little extra cost. If you look for a business called "HiFiSpot" it gives you a number of interesting thingsnow including a 500W amplifier with a -3dB point at 500kHz. I think this won't apply to continuous sine wave but I've just bought one and now have to build the huge power supply. The 300W amplifier I run from a 30+30V 5A supply with a toroidal transformer, unregulated. Good hunting, Hugh, M0DSZ > Hi Hugh > Were did you got the kit ? Is it still available ? > 73 de Luis > EA5DOM > > ------------------------------------------------------------------------ > *De:* owner-rsgb_lf_group@blacksheep.org > [mailto:owner-rsgb_lf_group@blacksheep.org] *En nombre de *LineOne > *Enviado el:* martes, 08 de diciembre de 2015 12:07 > *Para:* rsgb_lf_group@blacksheep.org > *Asunto:* Re: LF: TDA7498 2x100W audio PA for LF use ?? > > 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 > --------------070004000708080305000402 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 8bit It comes from HongKong via Ebay usually as a kit but also ready-built for only a little extra cost. If you look for a business called "HiFiSpot" it gives you a number of interesting thingsnow including a 500W amplifier with a -3dB point at 500kHz. I think this won't apply to continuous sine wave but I've just bought one and now have to build the huge  power supply.
The 300W amplifier I run from a 30+30V 5A supply with a toroidal transformer, unregulated.

Good hunting, Hugh, M0DSZ

Hi Hugh
 
Were did you got the kit ? Is it still available ?
 
73 de Luis
EA5DOM

De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de LineOne
Enviado el: martes, 08 de diciembre de 2015 12:07
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: LF: TDA7498 2x100W audio PA for LF use ??

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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