[amsat-bb] Re: homebrew Loop yagi

[John B. Stephensen]

I've have two directive systems loop yagis. The bandwidths are only slightly 
wider than yagis with straight elements so dimenional tolerances will be 
about the same. They are similar to HF quads. Each element behaves like 2 
stacked dipoles with bent ends. The only unforgiving antena is a helix.

73,

John
KD6OZH

----- Original Message ----- 
From: <w7lrd at comcast.net>
To: "NW VHF" <PNWVHFS at googlegroups.com>; "AMSAT-BB" <AMSAT-BB at amsat.org>
Sent: Thursday, January 29, 2009 18:25 UTC
Subject: [amsat-bb] homebrew Loop yagi


> Hello
> I am looking for some brain power from anyone who has built loop yagi's. 
> I am getting my information from The ARRL Antenna book 20th edition.   The 
> book says follow exactly, however.  It calls for alluminum elements 0.0325 
> thick, I have copper 0.025 thick.  It calls for 3/4" alluminum boom I have 
> 3/4 copper and some 1/2" stainless steel channel.  The feed to the driven 
> element is UT-14, I have a  short piece with a SMA already attached, will 
> connecting the SMA to a SMA-N adapter be acceptable?  I have seen the 
> pretty pictures of Directive Systems antennas 
> http://www.directivesystems.com/loopyagi.htm
> Same idea only different parts.  Are these things pretty "forgiving" or 
> are the components critical?  Also comparing the loop to a quagi the loop 
> widths are 1/4" wide and the quagi used #18 wire, why?  My intent is 
> satellites and/or terrestial.  Thanks for the bandwidth.
> 73 Bob W7LRD
> CN87
> AMSAT 28498
>
> --
> "if this were easy, everyone would be doing it"
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