Return-Path: Received: from rly-dd02.mx.aol.com (rly-dd02.mail.aol.com [172.19.141.149]) by air-dd06.mail.aol.com (v126.13) with ESMTP id MAILINDD063-b604b2784d02cb; Tue, 15 Dec 2009 07:45:09 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-dd02.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDD022-b604b2784d02cb; Tue, 15 Dec 2009 07:45:05 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NKWjS-0003ay-ER for rs_out_1@blacksheep.org; Tue, 15 Dec 2009 12:42:26 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NKWjR-0003ap-U6 for rsgb_lf_group@blacksheep.org; Tue, 15 Dec 2009 12:42:25 +0000 Received: from lnx503.hrz.tu-darmstadt.de ([130.83.156.232]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NKWko-0005C1-4w for rsgb_lf_group@blacksheep.org; Tue, 15 Dec 2009 12:43:52 +0000 Received: from FILE-SERVER-HST.hst.e-technik.tu-darmstadt.de (File-Server-HST.hst.e-technik.tu-darmstadt.de [130.83.212.129]) by lnx503.hrz.tu-darmstadt.de (8.14.2/8.14.2/HRZ/PMX) with SMTP id nBFCi6uL032629 for ; Tue, 15 Dec 2009 13:44:06 +0100 (envelope-from schaefer@hst.tu-darmstadt.de) Received: from [127.0.0.1] (helo=File-Server-HST.hst.e-technik.tu-darmstadt.de) by FILE-SERVER-HST.hst.e-technik.tu-darmstadt.de with AVK MailGateway; for ; Tue, 15 Dec 2009 13:44:06 +0100 Content-class: urn:content-classes:message MIME-Version: 1.0 X-MimeOLE: Produced By Microsoft Exchange V6.5 Date: Tue, 15 Dec 2009 13:44:07 +0100 Message-ID: <38A51B74B884D74083D7950AD0DD85E828AC77@File-Server-HST.hst.e-technik.tu-darmstadt.de> In-Reply-To: <20091215112352.36901F3863@smtps02.kuleuven.be> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: AW: LF: "Gain" between qrss3 and qrss10? Thread-Index: Acp9ed5D9JibPk8wReuLxsv1FiqExQAB5zTg From: =?iso-8859-1?Q?Stefan_Sch=E4fer?= To: X-AVK-Virus-Check: AVB 19.625;15.12.2009 X-PMX-TU: seen v0.99a by 5.5.8.383112, Antispam-Engine: 2.7.2.376379, Antispam-Data: 2009.12.15.123320 X-PMX-SPAMCHECK: outgoing mail X-Karma: unknown: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01CA7D84.49B6933B" Subject: AW: AW: LF: "Gain" between qrss3 and qrss10? X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.3 required=5.0 tests=HTML_50_60, HTML_FONTCOLOR_UNKNOWN,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-IP: 193.82.116.20 X-Mailer: Unknown (No Version) ------_=_NextPart_001_01CA7D84.49B6933B Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Mni tnx Rik for your answer! =20 No, you didn't spoil the fun at all ;-) =20 I have some remarks/ideas. The coil losses increase linear with the power but not more than linear.= So, 10x the power wouldn't decrease the antenna efficiency (if no arcing= occurs, of course). If we assume an antenna, e.g. in 8m height with many= toploads, then the efficiency will be poor but the capacitance will be hi= gh and thus the needed L will be small. Therefore we get a low voltage eve= n with very high power and due to the low efficiency we will keep the lega= l limit. So, if one has no possibility to increase the antenna height QRO= is one choice, especially when the operator is already in pension and can= not do a qso in qrss10000000000000000000000000 any more ;-)=20 =20 =20 =20 It should be possible to run a TX directly of the mains (giving about 330V= DC). But for 10kW the PSU current would be 33A, requiring something like= a 60000uF/450V elco, these large HV elco's cost a fortune (at QRL we rece= nty had to replace a 4700uF/450V capacitor, it costed over 200 Euro). And for a Class-D / Class-E amp running of 330V a 900V power FET might be= a bit on the edge for a foolprove TX (but since you are spending a fortun= e on elco's you can spend some more money on 1.5kV devices ;-) ). =20 Yes, you are right. But i mean i USA, where the voltage is 110V, you get= about 155V and thus the 900V FET would have 6 times more. For a class e= mode PA, 4x the voltage can be reached when SWR is correct(!) so there wo= uld be a goog savety factor. About the Capacitors: You could reduce the ne= eded C when using a 3 phase system (of the kitchen oven ;-) ). Then you wo= uld get about 268VDC and therefore a factor 3,35 to the 900V which will be= critical for the FETs when SWR is not absolutely constant 1:1, so better= using a IXFH24N100 ;-) =20 Really nice, that conversation! Tnx! =20 73, Stefan / DK7FC =20 =20 =20 =20 ------_=_NextPart_001_01CA7D84.49B6933B Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Mni tnx Rik= for your answer!

 =

No= , you didn’t spoil the fun at all ;-)

&n= bsp;

I have some= remarks/ideas.

Th= e coil losses increase linear with the power but not more than linear. So, 10x the power wouldn’t decrease the antenna efficiency (if no arcing occurs, of course). If we assume an antenna, e.g. in 8m height with many toploads, th= en the efficiency will be poor but the capacitance will be high and thus the needed L will be small. Therefore we get a low voltage even with very high power and due to the low efficiency we will keep the legal limit. So, if= one has no possibility to increase the antenna height QRO is one choice, espec= ially when the operator is already in pension and cannot do a qso in qrss10000000000000000000000000 any more ;-)

&n= bsp;

&n= bsp;

 

It should= be possible to run a TX directly of the mains (giving about 330V DC). = But for 10kW the PSU current would be 33A, requiring something like a 60000uF/450V elco, these large HV elco's cost a fortune (at QRL we recenty had to repla= ce a 4700uF/450V capacitor, it costed over 200 Euro).
And for a Class-D / Class-E amp running of 330V a 900V power FET might be= a bit on the edge for a foolprove TX (but since you are spending a fortune on el= co's you can spend some more money on 1.5kV devices ;-) ).

 <= /p>

Yes, you= are right. But i mean i USA, where the voltag= e is 110V, you get about 155V and thus the 900V FET would have 6 times more. For a class e mode PA, 4x= the voltage can be reached when SWR is correct(!) so there would be a goog sav= ety factor. About the Capacitors: You could reduce the needed C when using a= 3 phase system (of the kitchen oven ;-) ). Then you would get about 268VDC= and therefore a factor 3,35 to the 900V which will be critical for the FETs wh= en SWR is not absolutely constant 1:1, so better using a IXFH24N100 =A0;-)

 

Really= nice, that conversation! Tnx!

 

73, Stef= an / DK7FC

 

 

 

 

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