Return-Path: X-Spam-DCC: paranoid 1481; 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,SPF_PASS 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 u87CNIeA015341 for ; Wed, 7 Sep 2016 14:23:18 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1bhboG-0000k9-Bw for rs_out_1@blacksheep.org; Wed, 07 Sep 2016 13:18:32 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1bhboE-0000k0-DT for rsgb_lf_group@blacksheep.org; Wed, 07 Sep 2016 13:18:30 +0100 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1bhboB-0001hc-12 for rsgb_lf_group@blacksheep.org; Wed, 07 Sep 2016 13:18:29 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 37A8C20516 for ; Wed, 7 Sep 2016 14:18:24 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3sTjDH5WHWz105p for ; Wed, 7 Sep 2016 14:18:22 +0200 (CEST) Message-ID: <57D0058E.4020808@posteo.de> Date: Wed, 07 Sep 2016 14:18:22 +0200 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <579355A36AEE9D4FA555C45D556003AB5D7D9F9C@servigilant.vigilant.local> In-Reply-To: <579355A36AEE9D4FA555C45D556003AB5D7D9F9C@servigilant.vigilant.local> X-Scan-Signature: b42857a5fad6e32377447282c21f62b1 Subject: Re: LF: EA5DOM LF tests Content-Type: multipart/alternative; boundary="------------020704090202000200080608" 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 10.1.3.11 Status: O X-Status: X-Keywords: X-UID: 8699 This is a multi-part message in MIME format. --------------020704090202000200080608 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Hi Luis, Am 07.09.2016 13:33, schrieb VIGILANT Luis Fernández: > Ideas wellcome ! :-) > I like the W1YD design http://www.w1vd.com/137-500-500WTX.pdf Yes, a very typical design. I would use a different output transformer, with a higher AL value (>= 4000 nH/N^2). Then you need less primary and secondary turns. This can become relevant when using high power at low voltages. But 50W is almost nothing. The 240-77 is fine for several 100W. And your FETs have a very high input capacitance. This will warm up the 7667 at 137 kHz i think. And the rise times will rise :-) And so the switching losses are higher..... For 50W at 13.8V i would use an IRFZ48N or so, something with Ciss < 2 nF. This will work well with the 7667 then. At 50W you can use a normal 13.8 V power supply. The unregulated power supply will quickly lead to complaints from certain OMs as you know :-) So you need to add a regulation or very BIG caps. 48V is a good supply voltage for a PA. I would then tend to use IRFP260N FETs. But then you will need a better driver, something like TC4420 or even IXDD614CI :-) 73, Stefan > Don't need the keyer and would use an ICL7667 as dual mosfet driver > For the mosfets what I have here is a couple of IRFP3206 > I have a linear transformer with 2x24V outputs. Can be good for an > unregulated 48V supply > This is what the audio PA is using now > 73 de Luis > EA5DOM > > ------------------------------------------------------------------------ > *De:* owner-rsgb_lf_group@blacksheep.org > [mailto:owner-rsgb_lf_group@blacksheep.org] *En nombre de *DK7FC > *Enviado el:* miércoles, 07 de septiembre de 2016 12:58 > *Para:* rsgb_lf_group@blacksheep.org > *Asunto:* Re: LF: EA5DOM LF tests > > > Am 07.09.2016 12:16, schrieb VIGILANT Luis Fernández: >> Time for a D class PA ;-) >> Output filter and transformer core is already here, so should be easy >> to get some 50w or more (10dB) > > That sounds good. Can you show a schematic that you want to build up? > Which voltage, which FETs, which driver? > > 73, Stefan --------------020704090202000200080608 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hi Luis,

Am 07.09.2016 13:33, schrieb VIGILANT Luis Fernández:
Ideas wellcome ! :-)
 
Yes, a very typical design.
I would use a different output transformer, with a higher AL value (>= 4000 nH/N^2). Then you need less primary and secondary turns. This can become relevant when using high power at low voltages. But 50W is almost nothing. The 240-77 is fine for several 100W.
And your FETs have a very high input capacitance. This will warm up the 7667 at 137 kHz i think. And the rise times will rise :-) And so the switching losses are higher.....

For 50W at 13.8V i would use an IRFZ48N or so, something with Ciss < 2 nF. This will work well with the 7667 then. At 50W you can use a normal 13.8 V power supply.

The unregulated power supply will quickly lead to complaints from certain OMs as you know :-) So you need to add a regulation or very BIG caps.

48V is a good supply voltage for a PA. I would then tend to use IRFP260N FETs. But then you will need a better driver, something like TC4420 or even IXDD614CI :-)

73, Stefan
 
Don't need the keyer and would use an ICL7667 as dual mosfet driver
For the mosfets what I have here is a couple of IRFP3206
 
I have a linear transformer with 2x24V outputs. Can be good for an unregulated 48V supply
This is what the audio PA is using now 
 
73 de Luis
EA5DOM

De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de DK7FC
Enviado el: miércoles, 07 de septiembre de 2016 12:58
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: LF: EA5DOM LF tests


Am 07.09.2016 12:16, schrieb VIGILANT Luis Fernández:
 
Time for a D class PA  ;-)
Output filter and transformer core is already here, so should be easy to get some 50w or more (10dB)

That sounds good. Can you show a schematic that you want to build up? Which voltage, which FETs, which driver?

73, Stefan
--------------020704090202000200080608--