Return-Path: X-Spam-DCC: paranoid 1170; 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=-1.6 required=5.0 tests=BAYES_00,HTML_MESSAGE, NO_REAL_NAME 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 s9EBaaMn020473 for ; Tue, 14 Oct 2014 13:36:38 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Xe0Kh-0005Qt-Ni for rs_out_1@blacksheep.org; Tue, 14 Oct 2014 12:32:03 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Xe0Kh-0005Qk-C2 for rsgb_lf_group@blacksheep.org; Tue, 14 Oct 2014 12:32:03 +0100 Received: from resqmta-ch2-04v.sys.comcast.net ([69.252.207.36]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES128-SHA:128) (Exim 4.82) (envelope-from ) id 1Xe0Ke-0000on-KK for rsgb_lf_group@blacksheep.org; Tue, 14 Oct 2014 12:32:02 +0100 Received: from resomta-ch2-17v.sys.comcast.net ([69.252.207.113]) by resqmta-ch2-04v.sys.comcast.net with comcast id 2zXx1p0022TL4Rh01zXxXL; Tue, 14 Oct 2014 11:31:57 +0000 Received: from JAYDELL ([71.234.119.9]) by resomta-ch2-17v.sys.comcast.net with comcast id 2zXw1p00A0CFS1j01zXwKX; Tue, 14 Oct 2014 11:31:57 +0000 X-DKIM-Result: Domain=comcast.net Result=Signature OK Message-ID: <005c01cfe7a2$761d1790$6401a8c0@JAYDELL> From: To: References: <003a01cfe4b7$7706b4b0$4201a8c0@yourc44d19af4e> ,<005201cfe4c0$e985af60$4201a8c0@yourc44d19af4e> ,<00a801cfe4f7$936c7f50$4201a8c0@yourc44d19af4e> Date: Tue, 14 Oct 2014 07:31:56 -0400 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20140121; t=1413286317; bh=12Ew70D7NmXfTu8ycUw3G2G8VooUu59R4y7Ggq+sIGQ=; h=Received:Received:Message-ID:From:To:Subject:Date:MIME-Version: Content-Type; b=sx1adaC5pMl5doBZ86LpIHZOK3IxEpcQ7kwQyN9rS6Jwv2OANWxovlAfT/YPTefhR sHQomVKzKlwZcvib4b/dm5FtBpkXETTipwULxhhNC+rE5vVd8KiWYDJQ3s320a+8g2 c/qCRYVGi0HBW/aWs1snHnp0tndGX2VAmIrvmltwj3L45amYynPMAgYnpvDaIZGiaC fdwcKdELCOxH9gXMvZOoXV4ZrCxv74TW3xkOhFk3eYc+4Owgvj4qn6bEEvoNfu5q6E NeE97Y64m2eS2CLj0JSJiuM1Qogx6xMPX+DHdjvT0h2uxKlDh5GMTNb/nUKKF7NnsS 7lJeMaIsoy5VA== X-Scan-Signature: 91e1efbff209cbddb14bc9e018c2cfe8 Subject: LF: Re: Alternatives Re: STW34NB20 - used in a number of MF and LF PA designs Content-Type: multipart/alternative; boundary="----=_NextPart_000_0058_01CFE780.EE9906B0" 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: 775 This is a multi-part message in MIME format. ------=_NextPart_000_0058_01CFE780.EE9906B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Laurence At over twice the input capacitance expect my driver circuit to come up short ;~( . Jay W1VD WD2XNS WE2XGR/2 ----- Original Message ----- From: Laurence KL7 L To: rsgb_lf_group@blacksheep.org Sent: Monday, October 13, 2014 8:15 PM Subject: LF: Alternatives Re: STW34NB20 - used in a number of MF and LF PA designs Alan/Jack/Stefan/Steve and all - thanks for the feedback, and as described its all a matter of compromise but the new vertical structure FET Mesh designs seem to be reasonable with similar the lower R on ohm figures of the older devices - rise and fall times/input cap and gate charge all look dooable - just the dollar amount... Just for info - Ive taken the plunge and ordered STW70N60M2 600V VDs 0.031 Ohm on and Imax as 68A - Ill let you know how they work in cct but it looks like completely over the top Gold over engineered FET device but I need the insurance give the changes and sudden animal interventions/weather I get up here in Alaska - http://www.mouser.com/ProductDetail/STMicroelectronics/STW70N60M2/?qs=Rlwi1sSxVL4hmaII3E%2FvIA%3D%3D I temp switched over to a 600V FET, the end of life or about to be http://www.mouser.com/ProductDetail/STMicroelectronics/STW16N65M5/?qs=sGAEpiMZZMutXGli8Ay4kNbVQor0Njej2JFFy%252bQzHzg%3d this is a "smaller" I tot device and gets a little warmer than more lower Ron ohms 34NB20 but was running fine in 1Kw W1VD design with no change in tap points out optimizing the Voltage/Current ratios.... I have a pair of them at 300W out and effieciency was about 72% or so. I didnt see any peaky waveform on the drains either.. All being well Ill be on WSPR2 630m tonight - weather up here is far too warm - lake ice has melted and the ducks and Swans are back enroute South Laurence KL7L ------------------------------------------------------------------------------ From: jwaskew@telus.net To: rsgb_lf_group@blacksheep.org Date: Fri, 10 Oct 2014 19:03:39 -0700 Subject: LF: Re: : Re: STW34NB20 - used in a number of MF and LF PA designs Hi Laurence There is no easy answer to that problem. If there were some way you could reduce the time it takes to shut down the final using a faster circuit, it would reduce the chance of smoked FETs obviously. I guess it's the high winds that really cause the biggest problem there. The close proximity of our trees here limit me from leaving the amp unattended during winds. ------=_NextPart_000_0058_01CFE780.EE9906B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Laurence
 
At over twice the input = capacitance expect my=20 driver circuit to come up short ;~( .
 
Jay W1VD  WD2XNS =20 WE2XGR/2 
----- Original Message -----
From:=20 Laurence KL7 L =
Sent: Monday, October 13, 2014 = 8:15=20 PM
Subject: LF: Alternatives Re: = STW34NB20 -=20 used in a number of MF and LF PA designs

Alan/Jack/Stefan/Steve and all - thanks for the = feedback, and as=20 described its all a matter of compromise but the new vertical = structure =20 FET Mesh designs seem to be reasonable with similar the lower R on ohm = figures=20 of the older devices - rise and fall times/input cap and gate charge = all look=20 dooable - just the dollar amount...
 
Just for info - Ive = taken the=20 plunge and ordered
 
STW70N60M2 =20 600V VDs  0.031 Ohm on and Imax as 68A  - Ill let you = know how=20 they work in cct but it looks like completely over the top Gold over=20 engineered FET device but I need the insurance give the changes and = sudden=20 animal interventions/weather I get up here in Alaska - =
 
http://www.mouser.com/ProductDetai= l/STMicroelectronics/STW70N60M2/?qs=3DRlwi1sSxVL4hmaII3E%2FvIA%3D%3D<= /SPAN>
 
I =20 temp switched over to a 600V FET, the end of life or about to be http://www.mou= ser.com/ProductDetail/STMicroelectronics/STW16N65M5/?qs=3DsGAEpiMZZMutXGl= i8Ay4kNbVQor0Njej2JFFy%252bQzHzg%3d
 
this=20 is a "smaller" I tot device and gets a little warmer than more lower = Ron ohms=20 34NB20 but was running fine in 1Kw W1VD design with no change in tap = points=20 out optimizing the Voltage/Current ratios.... I have a pair of them at = 300W=20 out and effieciency was about 72% or so. I didnt see any peaky = waveform on the=20 drains either..
 
All=20 being well Ill be on WSPR2 630m tonight - weather up here is far too = warm -=20 lake ice has melted  and the ducks and Swans are back enroute=20 South
 
Laurence=20 KL7L
 
 

 
From: jwaskew@telus.net
To: rsgb_lf_group@blacksheep.org
Date: = Fri, 10=20 Oct 2014 19:03:39 -0700
Subject: LF: Re: : Re: STW34NB20 - used in = a number=20 of MF and LF PA designs

Hi Laurence
There is no easy answer to that = problem.  If=20 there were some way you could reduce the time it takes to shut down = the final=20 using a faster circuit, it would reduce the chance of smoked FETs = obviously.  I guess it's the high winds that really cause the = biggest=20 problem there. The close proximity of our trees here limit me from = leaving the=20 amp unattended during winds.
 
 
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