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=-2.6 required=5.0 tests=BAYES_00,HTML_MESSAGE autolearn=unavailable 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 s9E2GZWO018559 for ; Tue, 14 Oct 2014 04:16:35 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Xdrbf-0004NV-1s for rs_out_1@blacksheep.org; Tue, 14 Oct 2014 03:12:59 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Xdrbe-0004NM-Ht for rsgb_lf_group@blacksheep.org; Tue, 14 Oct 2014 03:12:58 +0100 Received: from cmta13.telus.net ([209.171.16.86]) by relay1.thorcom.net with esmtp (Exim 4.82) (envelope-from ) id 1Xdrbb-0007US-5t for rsgb_lf_group@blacksheep.org; Tue, 14 Oct 2014 03:12:57 +0100 Received: from yourc44d19af4e ([154.20.49.3]) by cmta13.telus.net with TELUS id 2qCs1p00R047uVm01qCsUk; Mon, 13 Oct 2014 20:12:53 -0600 X-Authority-Analysis: v=2.0 cv=OrmRPVDt c=1 sm=2 a=KwMu6Nbn3mKh2Z3zavZcgQ==:17 a=LGgl8L9ij00A:10 a=aatUQebYAAAA:8 a=JOA0iUbgAAAA:8 a=F3M5lZpKAAAA:8 a=_6GpL_ENAAAA:8 a=Zd50EyWgGXtux6zyQXQA:9 a=wPNLvfGTeEIA:10 a=rBKJJ2Jc0C4A:10 a=wk6s2zzMB60A:10 a=R8K97L4Em1a9ImV9zwcA:9 a=_W_S_7VecoQA:10 a=frz4AuCg-hUA:10 a=JqyJjvbokZy3DiA_:21 a=KwMu6Nbn3mKh2Z3zavZcgQ==:117 X-Telus-Outbound-IP: 154.20.49.3 Message-ID: <00d601cfe754$5c673310$4201a8c0@yourc44d19af4e> From: "Jack" To: References: <003a01cfe4b7$7706b4b0$4201a8c0@yourc44d19af4e> ,<005201cfe4c0$e985af60$4201a8c0@yourc44d19af4e> ,<00a801cfe4f7$936c7f50$4201a8c0@yourc44d19af4e> Date: Mon, 13 Oct 2014 19:12:52 -0700 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 X-Antivirus: avast! (VPS 141013-1, 10/13/2014), Outbound message X-Antivirus-Status: Clean X-Scan-Signature: 05df7db787776cda2726d56f546a4588 Subject: LF: Re: Alternatives Re: STW34NB20 - used in a number of MF and LF PA designs Content-Type: multipart/alternative; boundary="----=_NextPart_000_00D3_01CFE719.AF879250" 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: 771 This is a multi-part message in MIME format. ------=_NextPart_000_00D3_01CFE719.AF879250 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Very good Laurence, but with that $$ price I'd be afraid to use them just i= n case they did blow...ouch! You were good copy on WSPR last night and for first time into Campbell Rive= r BC, seen you between 10:02 and 14:06 with signal strengths averaging -24d= B. 73, Jack VA7JX Alan/Jack/Stefan/Steve and all - thanks for the feedback, and as describe= d its all a matter of compromise but the new vertical structure FET Mesh d= esigns 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 doo= able - 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 ho= w they work in cct but it looks like completely over the top Gold over engi= neered FET device but I need the insurance give the changes and sudden anim= al interventions/weather I get up here in Alaska - http://www.mouser.com/ProductDetail/STMicroelectronics/STW70N60M2/?qs=3DR= lwi1sSxVL4hmaII3E%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=3DsGAEpiMZ= ZMutXGli8Ay4kNbVQor0Njej2JFFy%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 t= hem 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 desig= ns Hi Laurence There is no easy answer to that problem. If there were some way you coul= d reduce the time it takes to shut down the final using a faster circuit, i= t 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 o= ur trees here limit me from leaving the amp unattended during winds. --- This email is free from viruses and malware because avast! Antivirus protec= tion is active. http://www.avast.com ------=_NextPart_000_00D3_01CFE719.AF879250 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Very good Laurence, but with that $$ price= I'd be afraid to use them just in case they did blow...ouch!
 
You were good copy on WSPR last night and = for first time into Campbell River BC, seen you between 10:02 and 14:06 with sig= nal strengths averaging -24dB.
 
73,
Jack VA7JX
 
 
  

Alan/Jack/Stefan/Steve and all - thanks for the feedback, = and as described its all a matter of compromise but the new vertical structure&n= bsp; FET Mesh designs seem to be reasonable with similar the lower R on ohm fi= gures of the older devices - rise and fall times/input cap and gate charge all = look dooable - just the dollar amount...
 
Just for info - Ive take= n 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 sudde= n animal interventions/weather I get up here in Alaska -
 
http://www.mouser.com/ProductDetail/= STMicroelectronics/STW70N60M2/?qs=3DRlwi1sSxVL4hmaII3E%2FvIA%3D%3D
 
I  temp switched over to a 600V FET, the end of life or about to be http://www.mouse= r.com/ProductDetail/STMicroelectronics/STW16N65M5/?qs=3DsGAEpiMZZMutXGli8Ay= 4kNbVQor0Njej2JFFy%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 poin= ts out optimizing the Voltage/Current ratios.... I have a pair of them at 30= 0W out and effieciency was about 72% or so. I didnt see any peaky waveform o= n 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 n= umber 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 f= inal using a faster circuit, it would reduce the chance of smoked FETs obviously.  I guess it's the high winds that really cause the bigges= t problem there. The close proximity of our trees here limit me from leavin= g the amp unattended during winds.
 
 


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