Return-Path: Sender: (Marvin Kaye) To: lml Date: Tue, 03 Sep 2002 14:54:03 -0400 Message-ID: X-Original-Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 4.0b7) with ESMTP id 1720896 for lml@lancaironline.net; Tue, 03 Sep 2002 14:33:57 -0400 Received: from dc-mx12.cluster1.charter.net ([209.225.8.22]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71866U8000L800S0V35) with ESMTP id com for ; Tue, 3 Sep 2002 14:26:06 -0400 Received: from [24.207.220.89] (HELO computer) by dc-mx12.cluster1.charter.net (CommuniGate Pro SMTP 3.5.9) with SMTP id 78804467 for lancair.list@olsusa.com; Tue, 03 Sep 2002 14:32:41 -0400 X-Original-Message-ID: <001b01c25377$d1d97be0$59dccf18@home.charterstl.com> From: "Bob Jude" X-Original-To: "Mail List Lancair" Subject: Comm Antenna Testing X-Original-Date: Tue, 3 Sep 2002 13:29:19 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit 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 " 2) You suggest shortening or lengthening the coax cable to adjust the SWR." This is a BAD idea. What you are doing with this procedure is "tuning" the cable/antenna combination to a single frequency. You still have standing waves on the cable even at the tuned frequency which results in radiation from the cable which mostly horizontal. This is wasted RF power. The goal must be to install an antenna which has less than 2/1 VSWR over the entire frequency band referenced to 50 ohms. Connect it to the comm set with a 50 ohm cable and you will have less than 2/1 VSWR at the cable over the entire frequency band. You do not want a tuned cable. You want a flat cable (electrically speaking). Bob Jude, N65BJ I am qualified to comment on the subject --- 40+ years in antenna and RF equipment design and test.