Return-Path: X-Spam-DCC: paranoid 1233; Body=3 Fuz1=3 Fuz2=3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,HTML_30_40, HTML_MESSAGE,MIME_HTML_ONLY 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 sBLKcd7U004503 for ; Sun, 21 Dec 2014 21:38:39 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Y2nA7-0006A6-0b for rs_out_1@blacksheep.org; Sun, 21 Dec 2014 20:31:35 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Y2nA0-00069x-Ce for rsgb_lf_group@blacksheep.org; Sun, 21 Dec 2014 20:31:28 +0000 Received: from mout.web.de ([212.227.17.11]) by relay1.thorcom.net with esmtp (Exim 4.84) (envelope-from ) id 1Y2n9x-0003Y0-9m for rsgb_lf_group@blacksheep.org; Sun, 21 Dec 2014 20:31:27 +0000 Received: from [87.184.109.198] by 3capp-webde-bs21.server.lan (via HTTP); Sun, 21 Dec 2014 21:31:23 +0100 MIME-Version: 1.0 Message-ID: From: "Hans-Albrecht Haffa" To: Langwellen-Reflektor Date: Sun, 21 Dec 2014 21:31:23 +0100 Importance: normal Sensitivity: Normal References: X-UI-Message-Type: mail X-Priority: 3 X-Provags-ID: V03:K0:GHrCeV5EbfsAxqrNI2G/VFcwP4KQB1RF3zIyMODu5s4 2aHMDWX8JW3JhRPwmoSNWStOj01VmowmkkdFywgXK0Az9+odP3 PBtFEy1p3HnG0GeZJEhEKTftHxmkqOYvJk4CkFQlWcjB9JtRvx LnNgcs9/Tv0nhQ5f51gDccQcS0HXtHZDdalo/oI9ywXYTeuFKt rao2k3rL9/MBH6HWEuTuWSpVRmNQ19mZ24fYPk7rwhZx6nfCBh hyPapD8al+JzGH6NguZjI5EhyxXSlvLlpFR48IrWyqTNmiSUhq N39fxw= X-UI-Out-Filterresults: notjunk:1; X-Scan-Signature: 4b5b5ebe37a4c4f430f59bc35c1947b0 Subject: LF: Fw: Low pass filter 1 kW 136k 472 k what components to choose? Tnx to all Content-Type: text/html; charset=UTF-8 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: 1558

Dear OMs,

thank You for the quick answer just in one day. Isn t it nice to get replies from technical experts just in a few hours?

I compared Your drafts with an already built construction of me using abt 80 mm ferrit toroids with cut slots and stacked mica caps 150 nF ( I nedded 30 nF, so I stacked 5 of them...). The air gaps I had cut with an saw designed to cut tiles from the home store. I measured transfer function s21 with the Vector-Antenna analyser from "Funkamateur", as it should be for an 7pole-filter. Just before I had done trash measurements with defective BNC-cables, so I wrote an e-mail to the reflector.

Gesendet: Sonntag, 21. Dezember 2014 um 16:38 Uhr
Von: "Hans-Albrecht Haffa" <dk8nd@web.de>
An: Langwellen-Reflektor <rsgb_lf_group@blacksheep.org>, "Hans-Albrecht Haffa" <dk8nd@web.de>
Betreff: Low pass filter 1 kW 136k 472 k what components to choose?

Dear OMs,
just a question strait forward: What componnets I should choose for a low pass filter for 136 kHz and 472 kHz, two filters to be designed.

136 kHz: Pin abt 1,5 kW

472 kHz: Pin abt 0,5 kW

SWR: s = 1...2,5 when mated, in case of failure more

a five-pole low pass will probably be sufficient.

My Question:

What iron powder cores or air coiles will do it, known or proofed by experiment? Diameter, marterial grade?

What capacitors? max. Voltage. High voltage caps from Wima (Ucd=4kV or 8 kV) are not available at distributors, mica capacitors will hardly fit in capacitiy value or in voltage, when in my collection.

The calculus of magnetic circuits is not a problem for me, but it is easier to start with components that will fulfill the demands.

Waiting to Your kind anwer,

55, Hans-Albrecht

DK 8 ND