Return-Path: X-Spam-DCC: paranoid 104; 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=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_MESSAGE 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 tAEKCMk1002178 for ; Sat, 14 Nov 2015 21:12:22 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Zxh8U-0007Er-L6 for rs_out_1@blacksheep.org; Sat, 14 Nov 2015 20:09:22 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Zxh8U-0007Ei-AM for rsgb_lf_group@blacksheep.org; Sat, 14 Nov 2015 20:09:22 +0000 Received: from mail-wm0-f44.google.com ([74.125.82.44]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1Zxh7Q-0006Zh-8X for rsgb_lf_group@blacksheep.org; Sat, 14 Nov 2015 20:09:21 +0000 Received: by wmec201 with SMTP id c201so125390500wme.0 for ; Sat, 14 Nov 2015 12:08:00 -0800 (PST) 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=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=/P32iSAeV7ekD/42+rxTOphd4oXLJiSr4bjP3wRPZYE=; b=VTdc6bU/lybxm6ipKrOJFfalwJJPuNAEBWoPhJZu7Y4PKTjkzCDNCUtBPnxaVPVqF5 1U2O2Xe1pcIt+5X2UQ9w/bF02JFxM7uhFQ6oVt9Xrqt9DktJXG3uHDa47Y8lX3UAequ0 v96jjyuNycHPXYsvxqfx8OPYdd6P9Eyp6zTDq4bkEkRAG15dbtDufAwNJQNq2Xj9gUw+ oRPF01+3zCN0eE+iUxMnwTG9NlS4rqpM0fr9mlnFZ313VzHSXUtuN2sTPtPYF2wRvbFz YkOkEeOrnZSwaXbJ08AF4RXwBVFhIdMdhdQ5dR2o/2DaocBGmxsMqUpjs7BEPygLOok+ yTyg== MIME-Version: 1.0 X-Received: by 10.28.51.135 with SMTP id z129mr1884687wmz.19.1447531680592; Sat, 14 Nov 2015 12:08:00 -0800 (PST) Received: by 10.28.130.139 with HTTP; Sat, 14 Nov 2015 12:08:00 -0800 (PST) In-Reply-To: <29180@WA7V> References: <4510637253.20151114190626@chriswilson.tv> <29180@WA7V> Date: Sat, 14 Nov 2015 20:08:00 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 21e2055b299bd63ed331c37c8a3e15ca Subject: Re: LF: Valve LF amps and tank coil size / voltage rating? Content-Type: multipart/alternative; boundary=001a1144424e9f7aa8052485bbd0 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: 5076 --001a1144424e9f7aa8052485bbd0 Content-Type: text/plain; charset=UTF-8 That 58mm diameter toroid will have a core cross section in the region of perhaps 300mm^2 (about 17mm square). 2000V DC supply if it is being used as a transformer, means something like 1400V RMS maximum across the winding . SO at 137kHz, keeping B to 0.1T, that means 1400 = 4.44.137k.N.300E-6..1, so Nmin = 76 turns. Double this for push-pull across the drains. If your ferrite core (with a an air gap) is being used as part of a tank resonator, then multiply the voltage across it , and hence the turns, the by the loaded Q; in which case it all gets very silly indeed. Andy G4JNT On 14 November 2015 at 19:54, Szigy wrote: > > the feritte core with 58mm OD, material 3C85. > Inspired by this article have built myself a 2xGU13 > (813) PA, 2000V x 0.4A, class C, it works ok in LF or MF ! > 73 & DX, Szigy. > -----my reply to----------------- > Date: Sat, 14 Nov 2015 19:06:26 +0000 > rom: Chris Wilson > rganization: Gatesgarth Developments > o: yo2is@wa7v.#sewa.wa.usa.noam > ubject: LF: Valve LF amps and tank coil size / voltage rating? > eply-To: rsgb_lf_group@blacksheep.org > 14 November 2015 > If you built a decent power valve LF amp what is the realistic voltage > imit to ferrite cored tank circuits? In other words, what plate > oltage / current is the limit for say a ferrite cored toroidal coil > efore you have to move on to an air cored (very large?) tank coil? > nyone have any links to the limiting figures? All the highish power > alved LF amps I can find are commercial and size was probably not an > ssue, but MAYBE they were pre ferrite toroids, I am not sure when > hey came into usage. Thanks. > - > > est regards, > Chris 2E0ILY mailto:chris@chriswilson.tv > > --001a1144424e9f7aa8052485bbd0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
That 58mm diameter toroid will have a core cross section i= n the region of perhaps =C2=A0300mm^2 =C2=A0(about 17mm square).
2000V = DC supply if it is being used as a transformer, means something like 1400V = RMS maximum across the winding .

SO at 137kHz, kee= ping B to 0.1T, that means=C2=A0
1400 =3D 4.44.137k.N.300E-6..1, = =C2=A0 so Nmin =3D 76 turns. =C2=A0 =C2=A0Double this for push-pull across = =C2=A0the drains.

If your ferrite core (with a an = air gap) is being used as part of =C2=A0a tank resonator, then multiply the= voltage=C2=A0across it=C2=A0, and hence the turns, the by the loaded Q; = =C2=A0in which case it all gets very silly indeed.

Andy =C2=A0G4JNT

On 14 November 2015 at 19:54, Szigy <yo2is@wa7v.ampr.org> wrote:

the feritte core with 58mm OD, material 3C85.
Inspired by this article have built myself a 2xGU13
(813) PA, 2000V x 0.4A, class C, it works ok in LF or MF !
=C2=A0 73 & DX, Szigy.
-----my reply=C2=A0 to-----------------
Date: Sat, 14 Nov 2015 19:06:26 +0000
rom: Chris Wilson <chris@chriswi= lson.tv>
rganization: Gatesgarth Developments
o: yo2is@wa7v.#sewa.wa.usa.noam
ubject: LF: Valve LF amps and tank coil size / voltage rating?
eply-To: rsgb_lf_group@blac= ksheep.org
14 November 2015
If you built a decent power valve LF amp what is the realistic voltage
imit to ferrite cored tank circuits? In other words, what plate
oltage / current is the limit for say a ferrite cored toroidal coil
efore you have to move on to an air cored (very large?) tank coil?
nyone have any links to the limiting figures? All the highish power
alved LF amps I can find are commercial and size was probably not an
ssue, but MAYBE they were pre ferrite toroids, I am not sure when
hey came into usage. Thanks.
-

est regards,
Chris=C2=A0 2E0ILY=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=A0mailto:chris@chriswilson.tv


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