Return-Path: Received: from rly-dc10.mx.aol.com (rly-dc10.mail.aol.com [172.19.136.39]) by air-dc08.mail.aol.com (v121.4) with ESMTP id MAILINDC082-b4c475e6d182e6; Tue, 11 Dec 2007 05:57:56 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-dc10.mx.aol.com (v121.4) with ESMTP id MAILRELAYINDC108-b4c475e6d182e6; Tue, 11 Dec 2007 05:57:30 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1J22mk-0003n3-OF for rs_out_1@blacksheep.org; Tue, 11 Dec 2007 10:56:22 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1J22mk-0003mu-4o for rsgb_lf_group@blacksheep.org; Tue, 11 Dec 2007 10:56:22 +0000 Received: from smtp806.mail.ird.yahoo.com ([217.146.188.66]) by relay3.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1J22mh-0007ie-PV for rsgb_lf_group@blacksheep.org; Tue, 11 Dec 2007 10:56:22 +0000 Received: (qmail 89883 invoked from network); 11 Dec 2007 10:56:14 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=Received:X-YMail-OSG:From:To:Subject:Date:Message-ID:MIME-Version:Content-Type:X-Mailer:X-MimeOLE:Thread-Index; b=Qv8beh6+iUjyjJbKj3wax0rU55AMnq9KUZ4lr5RRE7oDqAV23gtcp5kED32AiBwCYHQvL9z+oT0uW9XL1UScf+r7pV7leUZpbQOyMWVxwqv9/qxH0OdLMuON7p9UQQ99iBaziFj79trt51VjD43vYYrtT2EjnRYck1PdXhCmYoA= ; Received: from unknown (HELO ken) (ken.h.wright@btinternet.com@86.140.79.65 with login) by smtp806.mail.ird.yahoo.com with SMTP; 11 Dec 2007 10:56:14 -0000 X-YMail-OSG: HnKoF_IVM1kgNtY7I32n5cIObUR.iCv.6H_GJRNaHQESZ0aIjJ6Or8x4jBJmQMcvbvSMJMemqSgpgvL32MnwTEMczejwCEV_a2HIrLrJAhXwjW.hDt2.GtfIwy4- From: "Ken Wright" To: Date: Tue, 11 Dec 2007 10:56:26 -0000 Message-ID: <001201c83be4$79fff920$0401a8c0@ken> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 Thread-Index: Acg75HmbN5V5Cmg+S+GMa2AakGr+aA== DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: IRF530N in 500kHz PA Content-Type: multipart/alternative; boundary="----=_NextPart_000_0013_01C83BE4.79FFF920" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_40_50,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-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_helo : n X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_822_from : n ------=_NextPart_000_0013_01C83BE4.79FFF920 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Has anyone experienced problems using an IRF530N in a 500kHz PA?. I am using= an IRF530N into an L =E2=80=93 C =E2=80=93 L output network the design par= ameters for the network are input:10 ohms, output 50 ohms, centre frequency=20= 502.5 kHz, Q =3D 12, giving, L1 38=C2=B5H, C1 3.7nF, L2 84=C2=B5H, C1 cons= ists of a 3.3nF fixed capacitor plus a 2 gang 500pF variable, 3mH inductor i= n the drain. I have tried driving the MOSFET with a 5v positive peak signal,= and with a 3v rms signal sitting on a +ve bias, I have managed to obtain 5w= into a Marconi TF1152A/1 (50=CE=A9) power meter about three times, but when= 12v is removed from the PA and reconnected there is no output, C1 is adjust= ed for maximum power output, but is never the same position twice, and there= seems to be a very critical adjustment of the drive to obtain, a) an output= , b) anything that looks like a sine wave, although when I have got it right= there is a very good sine wave. Any ideas anyone as to what may be going wr= ong?=20 =20 My direct e-mail is ken.h.wright@btinternet.com =20 =20 73 Ken Wright M0KHW IO91TV ------=_NextPart_000_0013_01C83BE4.79FFF920 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

Has anyone experienced problems us= ing an IRF530N in a 500kHz PA?. I am using an IRF530N into an L =E2=80=93 C =E2=80=93 L =C2=A0ou= tput network the design parameters for the network are input:10 ohms, output 50 ohms, centre frequen= cy 502.5 kHz, Q =3D 12, giving, L1 =C2=A038=C2=B5H, C1 3.7nF, L2 =C2=A084=C2= =B5H, C1 consists of a 3.3nF fixed capacitor plus a 2 gang 500pF variable, 3mH inductor in the drain. I h= ave tried driving the MOSFET with a 5v positive peak signal, and with a 3v rms signal sitting on a +ve bias, I have managed to obtain 5w into a Marconi TF1= 152A/1 (50=CE=A9) power meter about three times, but when 12v is removed from the P= A and reconnected there is no output, C1 is adjusted for maximum power output, but= is never the same position twice, and there seems to be a very critical adjustm= ent of the drive to obtain, a) an output, b) anything that looks like a sine wav= e, although when I have got it right there is a very good sine wave. Any ideas anyone as= to what may be going wrong?

 

My direct e-mail is=C2=A0 ken.h.wright@btinternet.com=

 

 

73=C2=A0=C2=A0 Ken Wright=C2=A0= =C2=A0 M0KHW=C2=A0=C2=A0=C2=A0 IO91TV

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