Return-Path: Received: (qmail 1982 invoked from network); 11 Nov 2003 22:08:59 -0000 Received: from unknown (HELO netmail01.services.quay.plus.net) (212.159.14.219) by mailstore with SMTP; 11 Nov 2003 22:08:59 -0000 Received: (qmail 20857 invoked by uid 10001); 11 Nov 2003 22:08:59 -0000 X-Priority: 3 X-MSMail-Priority: Normal X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from post.thorcom.com (193.82.116.20) by netmail01.services.quay.plus.net with SMTP; 11 Nov 2003 22:08:46 -0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1AJgg7-00055n-0g for rsgb_lf_group-outgoing@blacksheep.org; Tue, 11 Nov 2003 22:08:03 +0000 Received: from [64.12.136.8] (helo=imo-m05.mx.aol.com) by post.thorcom.com with esmtp (Exim 4.14) id 1AJgg6-0004xt-8l for rsgb_lf_group@blacksheep.org; Tue, 11 Nov 2003 22:08:02 +0000 X-Fake-Domain: DL4YHF@aol.com Received: from DL4YHF@aol.com by imo-m05.mx.aol.com (mail_out_v36_r1.1.) id l.3a.40d2d5da (3932) for ; Tue, 11 Nov 2003 17:07:21 -0500 (EST) From: DL4YHF@aol.com Message-ID: <3a.40d2d5da.2ce2b799@aol.com> Date: Tue, 11 Nov 2003 17:07:21 EST To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Mailer: 8.0 for Windows sub 6104 Subject: Re: LF: Dummy-Load on LW Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Status: No, hits=0.3 required=5.0 tests=HTML_MESSAGE,NO_REAL_NAME autolearn=no version=2.60 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Spam-Rating: 1 Content-transfer-encoding: 8bit Hello Walter and group,

> DK8ND's email raises an interesting point. Can any of our German friends tell me why an impedance of 60 ohms was popular in Germany for some time but not anywhere else?
<
I think 60 Ohms was once popular because it was one quarter of the once widely used symmectric 240 Ohm systems. Easy to build baluns from 240 to 60 Ohms. I remember our old tube-equipped TV had such a balun.
Next question.. why 240 Ohms for symmetric lines ? ..  possibly because of the folded dipole.

This may be only one -probably the wrong- explanation. Another may be the loss on a 60 Ohm cable at higher frequencies is a bit lower than in a 50 Ohm cable.


Regards,
Wolf DL4YHF.