Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,RCVD_IN_DNSWL_MED, SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v3FGidkB024078 for ; Sat, 15 Apr 2017 18:44:40 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1czQlT-0000OO-V8 for rs_out_1@blacksheep.org; Sat, 15 Apr 2017 17:41:35 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1czQlT-0000OF-IE for rsgb_lf_group@blacksheep.org; Sat, 15 Apr 2017 17:41:35 +0100 Received: from mail-yw0-x236.google.com ([2607:f8b0:4002:c05::236]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1czQlQ-00069T-Dl for rsgb_lf_group@blacksheep.org; Sat, 15 Apr 2017 17:41:34 +0100 Received: by mail-yw0-x236.google.com with SMTP id l189so43996547ywb.0 for ; Sat, 15 Apr 2017 09:41:31 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=z59O22eJPQyy/azDukW2H5dSlCWeyBJZIJn8P7ilX98=; b=hM3W3ruqLYJ8h2E7G3y5QyCZTlSOFsuBh5vZvxQ5idV8U4o06h9oz3HC5oiqmszSas +QWR2J3vp+CIWf4SriHCnBOfKKaq6kk8fv1esHSohGXFj3v0OfXYzp/343wHAPZ0pWvH o1T7miyuTUi0z9LOMph/yirNIpqW4Qj0mjnJ7YIubGXQ3G8jWOTXk+RzKI+9BIYkth93 PtnL2NmB7f35YfNy/xt9YQjPPOIfyDuFTb1RnnbwIxTwcGTR/pKMITa0vpOvTf3AOwRs xQaqIH9C5dZsK2D6R8G9bsBDizOq2ja6ovyflCGqB7uo9YXxlHYuFsjSUufVLsba4ysw eZTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=z59O22eJPQyy/azDukW2H5dSlCWeyBJZIJn8P7ilX98=; b=jnIgRltmy7RLxd1pSUf9hNrCf9p35Cq1MfRHfgzOKNmDzw7uIGRPVgn022s6e3F2Hq W0R0ZKMMoMCslqLreVhgPDfZci3hdycp2gP8GVOrcaqq7rcXF7u/q3xP2YIkp8346kUa VF3tkgc9AxHcbvC03j7hSXenM/rHyfYTlV8KP04L+XJxxi/FXK5PbmAGZyn3qlViH+sk /wWo5VeKxvKTg+rrlhp9EulZ1+TQi7n/JTIPCNh45/tBLHIPneke6V+wlC06LZhxEdPj F+mPLbAtU1ngx5Ap6NERnXakx3didMenzr2m8/k0z2p24D4NN0nNwNi7uccHm3NMUeVy DadA== X-Gm-Message-State: AN3rC/5n0YetrmIq9KHOMK/P7cosFRLF65mgDVJZfjYMo2xg6Tkbtl4O fAh3Vc257k1EcYzgHEoXMqr4r5Ei4w== X-Received: by 10.129.46.207 with SMTP id u198mr10130428ywu.240.1492274489854; Sat, 15 Apr 2017 09:41:29 -0700 (PDT) MIME-Version: 1.0 Received: by 10.129.173.1 with HTTP; Sat, 15 Apr 2017 09:41:29 -0700 (PDT) In-Reply-To: <77F04AF2145840F3A96644843D629A87@AGB> References: <272136023.20170415133220@gmail.com> <20623F28F103422F8F6F961B025E44C1@AGB> <448397363.20170415151022@gmail.com> <77F04AF2145840F3A96644843D629A87@AGB> From: Andy Talbot Date: Sat, 15 Apr 2017 17:41:29 +0100 Message-ID: To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 7a302ec14fb4a62f16f049454b6dc54d Subject: Re: LF: Poor aerial connection affecting gate waveforms?? Content-Type: multipart/alternative; boundary=001a11408cd0e02e58054d373a9d 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 2.75 Status: O X-Status: X-Keywords: X-UID: 11325 --001a11408cd0e02e58054d373a9d Content-Type: text/plain; charset=UTF-8 I don't know why more designs based on them haven't appeared. Other than my half bridge version running from 320V DC from raw rectified mains, all the other high power amps around seem to use the classic pair of devices into a push-pull transformer. With all the baggage such designs entail. 50V supply, full H-bridge, tank on the output from the bridge, single DC isolation / impedance matching transformer. No inductors other than the (ideally air cored ) one in the tank. Can use the Decca guard circuity, which beats hands-down all these trips and overcurrent and drive failure arrangements. The advantage of doing one from a 50 - 100V rail over my direct mains one is that drive to the FETs doesn't have to go though an isolation transformer. You can get complete single-chip H-bridge driver chips that handle the bootstrapped supply and just need a logic level drive signal. Andy G4JNT On 15 April 2017 at 17:27, Graham wrote: > Can only go by the images in the links I sent a while back .. I was > wondering, after Andy's last post , > > Why not simply build a copy of the Decca out put stage , series > tuned cct's and the 3 -2-1 adding transformer > there must be enough of them about, for the transformers and chokes > to be identified , the same or similar must be about .. > tried and tested configuration ? > > Taking everything , via the , what appears to be , a step up , > transformer , will provide isolation from the Ae , if you combine at > 50 ohms , then everything will pass back to the amps , via the > combiner , > > Could be totally wrong of course, but there must of been a reason > for the lay out , when other multi unit pa's used 50 ohm combining > networks > but its tried and tested and what's better than 2 500w power > modules ? .. 3 of course ,) > > 73-G, > > > > > > -------------------------------------------------- > From: "Chris Wilson" > Sent: Saturday, April 15, 2017 3:10 PM > To: "Graham" > Subject: Re: LF: Poor aerial connection affecting gate waveforms?? > > Hello Graham, >> >> Saturday, April 15, 2017, 2:14:17 PM, you wrote: >> >> >>> >>> Chris, >>> >>> I assume , due to the Q any small variation , will move the >>> tune point about , but looking in the data base , Signals , >>> better last night to sv8 than the previous night , and may be >>> up 1 db at pa7 , not to say the noise was less , but at -10 db >>> that level will be much higher than the local noise level , >>> should be a reliable indication >>> >>> How important are the wave forms ? >>> >>> 73-G, >>> >> >> >> I don't know how important they are I am not a FET ;) All I know is >> the output transformer and the LP filter bank central toroid run a lot >> cooler if the wave forms aren't all spiky. I hope someone can say how >> critical this is? Nothing went pop, so presumably not ultra critical, >> but heat = lost power I would think? Cheers G! >> >> >> -- >> Best regards, >> Chris mailto:dead_fets@gmail.com >> >> >> > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > > --001a11408cd0e02e58054d373a9d Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I don't know why more designs based on them haven'= t appeared.=C2=A0 Other than my half bridge version running from 320V DC fr= om raw rectified mains, all the other high power amps around seem to use th= e classic pair of devices into a push-pull transformer. With all the baggag= e such designs entail.

50V supply, =C2=A0 full H-bridge,= tank on the output from the bridge, single DC isolation / impedance matchi= ng transformer. =C2=A0 =C2=A0No inductors other than the =C2=A0(ideally air= cored ) one in the tank. =C2=A0 =C2=A0Can use the Decca guard circuity, wh= ich beats hands-down all these trips and overcurrent and drive failure arra= ngements.

The advantage of doing one from a 50 - 1= 00V rail over my direct mains one is that drive to the FETs doesn't hav= e to go though an isolation transformer.=C2=A0 You can get complete single-= chip H-bridge driver chips that handle the bootstrapped supply and just nee= d a logic level drive signal.

Andy =C2=A0G4JNT

On 15 Apr= il 2017 at 17:27, Graham <g8fzk@g8fzk.fsnet.co.uk> wro= te:
Can only go=C2=A0 by the=C2=A0 images= =C2=A0 in the links=C2=A0 I sent a while back .. I was wondering,=C2=A0 aft= er=C2=A0 Andy's=C2=A0 last post ,

Why not=C2=A0 simply=C2=A0 build a=C2=A0 copy=C2=A0 of the=C2=A0 =C2=A0Decc= a=C2=A0 out put=C2=A0 stage ,=C2=A0 series tuned cct's=C2=A0 and the=C2= =A0 3 -2-1=C2=A0 adding=C2=A0 transformer
there=C2=A0 must be enough=C2=A0 of them=C2=A0 about,=C2=A0 for the=C2=A0 t= ransformers=C2=A0 and chokes to be=C2=A0 identified , the=C2=A0 same=C2=A0 = or=C2=A0 similar must be=C2=A0 about ..
tried and tested configuration ?

Taking=C2=A0 everything , via=C2=A0 the=C2=A0 , what appears to=C2=A0 be , = a step=C2=A0 up , transformer , will=C2=A0 provide=C2=A0 isolation=C2=A0 fr= om=C2=A0 the=C2=A0 Ae=C2=A0 , if you combine=C2=A0 at 50 ohms , then=C2=A0 = everything=C2=A0 will=C2=A0 pass=C2=A0 back to the=C2=A0 amps , via the com= biner ,

Could be=C2=A0 totally=C2=A0 wrong=C2=A0 of course, but there must of=C2=A0= been a=C2=A0 reason=C2=A0 for the=C2=A0 lay out ,=C2=A0 when=C2=A0 other= =C2=A0 multi unit=C2=A0 pa's=C2=A0 used=C2=A0 50 ohm=C2=A0 combining ne= tworks
but its=C2=A0 tried and=C2=A0 tested and=C2=A0 what's better=C2=A0 than= =C2=A0 2=C2=A0 =C2=A0500w power modules ? .. 3 of course ,)

73-G,





--------------------------------------------------
From: "Chris Wilson" <dead.fets@gmail.com>
Sent: Saturday, April 15, 2017 3:10 PM
To: "Graham" <rsgb_lf_group@blacksheep.org>
Subject: Re: LF: Poor aerial connection affecting gate waveforms??

Hello Graham,

Saturday, April 15, 2017, 2:14:17 PM, you wrote:



Chris,

I assume , due to the=C2=A0 Q any small=C2=A0 variation , will=C2=A0 move= =C2=A0 the
tune=C2=A0 point=C2=A0 about , but=C2=A0 looking=C2=A0 in the=C2=A0 =C2=A0d= ata base , Signals ,
better last night=C2=A0 to=C2=A0 sv8 than=C2=A0 the=C2=A0 =C2=A0previous ni= ght , and=C2=A0 may be
up=C2=A0 1 db at pa7=C2=A0 , not to say=C2=A0 the=C2=A0 noise was less , bu= t=C2=A0 at=C2=A0 -10 db
that level=C2=A0 =C2=A0will=C2=A0 be=C2=A0 much=C2=A0 higher=C2=A0 than the= =C2=A0 local noise level ,
should be a=C2=A0 reliable=C2=A0 indication

How important=C2=A0 are the=C2=A0 wave forms ?

73-G,


I don't know how important they are I am not a FET ;) All I know is
the output transformer and the LP filter bank central toroid run a lot
cooler if the wave forms aren't all spiky. I hope someone can say how critical this is? Nothing went pop, so presumably not ultra critical,
but heat =3D lost power I would think? Cheers G!


--
Best regards,
Chris=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 mailto:dead_fets@gmail.com



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