Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mj02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 46480380000E3; Tue, 5 Feb 2013 12:58:02 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1U2mlL-00026r-Sl for rs_out_1@blacksheep.org; Tue, 05 Feb 2013 17:56:55 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1U2mlL-00026i-9R for rsgb_lf_group@blacksheep.org; Tue, 05 Feb 2013 17:56:55 +0000 Received: from out1.ip06ir2.opaltelecom.net ([62.24.128.242]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1U2mlI-00007j-Vn for rsgb_lf_group@blacksheep.org; Tue, 05 Feb 2013 17:56:54 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AmEJAI1GEVFcECZf/2dsb2JhbABFFoIzg3+hLAOWYgSBAxdzghoFAQEEAQgBAQMWMwIsAQEDBQIBAxEEAQEKIQICFAEECBIGFggGEwoBAgIBAYduAwkKCKd1gkCGSw0ViUGMFoEdBRmCd4ETA44HhkKCdYoihROCfg X-IronPort-AV: E=Sophos;i="4.84,609,1355097600"; d="scan'208,217";a="564927810" Received: from host-92-16-38-95.as13285.net (HELO xphd97xgq27nyf) ([92.16.38.95]) by out1.ip06ir2.opaltelecom.net with SMTP; 05 Feb 2013 17:56:28 +0000 Message-ID: <002c01ce03ca$1d9b09a0$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: , <5110C6B8020000FA0001897D@gw1.sron.nl> Date: Tue, 5 Feb 2013 17:56:24 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 2.3 (++) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. 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Content preview: Victor This is also my observation and except the swithing is spot on it wil just kill the PA FET The Drain trailing edge needs to adjusted to eliminate voltage spikes and should appear rounded towards the next cycle. g3kev [...] Content analysis details: (2.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 2.3 AXB_XMAILER_MIMEOLE_OL_024C2 AXB_XMAILER_MIMEOLE_OL_024C2 X-Scan-Signature: e51657317b06d9cbe905ec682fad6602 Subject: Re: Re: LF: My transmit converter description Content-Type: multipart/alternative; boundary="----=_NextPart_000_0029_01CE03CA.1D320EA0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,HTML_MESSAGE autolearn=no version=2.63 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-aol-global-disposition: G x-aol-sid: 3039ac1d7b965111482a0040 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_0029_01CE03CA.1D320EA0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Victor This is also my observation and except the swithing is spot on it wil = just kill the PA FET=20 The Drain trailing edge needs to adjusted to eliminate voltage spikes = and should appear rounded towards the next cycle. g3kev ----- Original Message -----=20 From: Eike Katzera=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Tuesday, February 05, 2013 9:13 AM Subject: Aw: Re: LF: My transmit converter description Hi Dimitros, the pulse shape in this picture does not look good: = http://people.physics.anu.edu.au/~dxt103/472/nltt/vk1sv-drain.jpg The reason seams to be the duty cycle at the gate. Please try to = change R5 to a 100k potentiometer and trim it to a clean single Pilse an = the drain. I solved the same problem tha way in my PA, wich killed my = IRF540. Kind regards Eike DL3IKE PS: sorry for my english ;) Gesendet: Dienstag, 05. Februar 2013 um 08:45 Uhr Von: "Victor van Kooten" An: rsgb_lf_group@blacksheep.org Betreff: Re: LF: My transmit converter description=20 Looks very nice Dimitris,hope to see/hear you soon, 73 Victor >>> Dimitrios Tsifakis 05/02/2013 01:50 >>> Hello group, My transmit converter is now finished and tested - it survived two sessions of 50% duty cycle WSPR transmissions on 475 kHz and the results are great. I thought others may find this useful, so I have put a write-up on my web page: http://people.physics.anu.edu.au/~dxt103/472/nltt/=20 It is a 50 W class-e PA designed for 50 ohm impedance, so there is no need for an impedance transformer. Doesn't get simpler than that :-) The driving circuit is based on G3XBM Roger's design with the difference of a 10 MHz OCXO LO and the addition of a beefy MOSFET driver. 73, Dimitris VK1SV ------=_NextPart_000_0029_01CE03CA.1D320EA0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Victor
This is also my observation and except the = swithing is=20 spot on it wil just kill the PA FET
The Drain trailing edge needs to adjusted to = eliminate=20 voltage spikes and should appear rounded towards the next = cycle.
g3kev
 
----- Original Message -----
From:=20 Eike = Katzera
Sent: Tuesday, February 05, = 2013 9:13=20 AM
Subject: Aw: Re: LF: My = transmit=20 converter description

Hi Dimitros,
the pulse shape in this picture does not look good: http://people.physics.anu.edu.au/~dxt103/472/nltt/vk1sv-drain.jpg
The reason seams to be the duty cycle at the gate. Please try to = change=20 R5 to a 100k potentiometer and trim it to a clean single Pilse an the = drain. I=20 solved the same problem tha way in my PA, wich killed my = IRF540.
Kind=20 regards
Eike DL3IKE
PS: sorry for my english ;)
Gesendet: Dienstag, = 05. Februar=20 2013 um 08:45 Uhr
Von: "Victor van Kooten"=20 = <V.A.G.van.Kooten@sron.nl>
An: rsgb_lf_group@blacksh= eep.org
Betreff: Re:=20 LF: My transmit converter description
Looks very nice Dimitris,hope to see/hear = you=20 soon,

73

Victor

>>> Dimitrios Tsifakis=20 <dtsifakis@gmail.com> 05/02/2013 01:50 >>>
Hello=20 group,

My transmit converter is now finished and tested - it = survived=20 two
sessions of 50% duty cycle WSPR transmissions on 475 kHz and=20 the
results are great. I thought others may find this useful, so I=20 have
put a write-up on my web page:

http://people.physics.anu.edu.au/~dxt103/472/nltt/ =

It is a 50 W class-e PA designed for 50 ohm impedance, so = there is=20 no
need for an impedance transformer. Doesn't get simpler than that = :-)
The driving circuit is based on G3XBM Roger's design with=20 the
difference of a 10 MHz OCXO LO and the addition of a beefy=20 MOSFET
driver.

73, Dimitris=20 VK1SV




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