From owner-qrp-l@Lehigh.EDU Thu Nov 7 07:12:06 1996 Received: from fidoii.CC.Lehigh.EDU (fidoii.CC.Lehigh.EDU [128.180.1.4]) by oucsace.cs.ohiou.edu (8.7.6/8.7.1) with ESMTP id HAA19559 for ; Thu, 7 Nov 1996 07:12:05 -0500 (EST) X-Received-x: from fidoii.CC.Lehigh.EDU (fidoii.CC.Lehigh.EDU [128.180.1.4]) by oucsace.cs.ohiou.edu (8.7.6/8.7.1) with ESMTP id HAA19559 for ; Thu, 7 Nov 1996 07:12:05 -0500 (EST) Received: from Lehigh.EDU ([127.0.0.1]) by fidoii.cc.lehigh.edu with SMTP id <35290-36900>; Thu, 7 Nov 1996 07:11:35 -0500 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <34887-15394>; Thu, 7 Nov 1996 07:10:29 -0500 Received: from utkux4.utcc.utk.edu (UTKUX4.UTCC.UTK.EDU [128.169.76.11]) by nss2.CC.Lehigh.EDU (8.8.2/8.8.2) with SMTP id HAA45114 for ; Thu, 7 Nov 1996 07:10:24 -0500 Received: from localhost by utkux4.utcc.utk.edu with SMTP (SMI-8.6/2.7c-UTK) id MAA24542; Thu, 7 Nov 1996 12:08:48 GMT Message-Id: Date: Thu, 7 Nov 1996 07:08:47 -0500 (EST) Reply-To: cebik@utkux.utcc.utk.edu Sender: owner-qrp-l@Lehigh.EDU Precedence: bulk From: "L. B. Cebik" To: "Low Power Amateur Radio Discussion" Subject: Too much F-B? MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-To: QRP-L List X-Sender: cebik@utkux4.utcc.utk.edu X-Listprocessor-Version: 8.0 -- ListProcessor(tm) by CREN Status: RO Received a good note from Keith, KB2VUO, who reported on some of the antenna planning BARC is doing for next Field Day. Yes, this is the season to plan, since it allways plenty of time to accumulate parts and build and test. I asked Keith to report on BARC's decision process, since it carefully addressed questions such as "What is the best antenna both in mechanical and pattern terms for the areas we want to contact in the test?" One consideration was the possibility of choosing an antenna with too much front-to-back ratio. That's right, TOO MUCH F-B ratio. Now, if you live on a coast and want to work an all-USA test, then all the F-B ratio you can get is advisable on any band. Big Yagis/quads, Vee beams, ZL/Field Day Specials, Moxons, and the like feature high rear nulls, and some of those designs might fit your need on any band. But if you want to hear what is happening behind you, without it interfering with current communications in front of you, choose an antenna with a lower F-B ratio. X-beams, and 2-element Yagis work well in this regard, with 10-12 dB F-B (about 2 S-units). You can hear and then possibly even work without turning the beam. For net control stations, these lower F-B designs may be more useful than those Long Johns. On one net I attend, I end up being asked by the NCS with a 3-element beam if I hear anyone he doesnot, since my little 2-element job hears better off the rear. Principle: assuming you have a choice (and often we do not), select your antenna design after careful analysis of the communicating you want to do--and the communicating you do not want to do. Then ask a series of questions: What can I afford ($)? What can I erect? What can I maintain? What is permissible, both legally and socially, where I plan to put the antenna? What is safe at this location? Each answer contributes to the final decision, and no two decisions are likely to be identical. But each decision is instructive for the next person--if you take the time to explain not only what antenna you suggest, but also why. My thanks to Keith for filling me in on the BARC deliberations. I hope he passes them on to everyone as an example of good planning. -73- LB, W4RNL