The following comments were well worth more that $.05.
come to chicagoland and I'll buy you a drink and pay you your nickel.
Learned a lot from this thread.
----- Original Message -----
From: Eric Gustafson <n7cl@mmsi.com>
To: <towertalk@contesting.com>; <km1r@snet.net>
Sent: Sunday, October 03, 1999 1:50 PM
Subject: Re: [TowerTalk] yagis vs. log periodics
>
>
> Hi Mike,
>
To: <towertalk@contesting.com>
> >Date: Sat, 02 Oct 1999 20:51:35 -0400
> >From: "Michael J. Castellano" <km1r@snet.net>
> >
> >The best part about this site is the ongoing discussions
> >(debates) that I find fascinating.
>
> Ditto...
>
>
>
> >My two and a half cents: The comparison of a log vs. yagi is
> >like comparing a cargo ship to a passenger ship. They are both
> >ships, but do different tasks.
>
> There is a class of Yagi which it is valid to compare to the
> LPDA. These are the parasitic arrays which attempt to cover 3 to
> 5 bands on a single boom with a single feedline. Against these,
> the LPDA doesn't do badly if the boom length under consideration
> is in the 30 or a bit more foot range (and longer).
>
>
> >
> >So I guess we can never really say one is better than the other.
>
> Not without first defining what "better" means and what size
> constraints must be met.
>
>
> >Here: I use a HY-Gain Telex LP-1007A at 60 feet for one purpose:
> >my work Involves multifrequencies and the requirement for faaast
> >qsy. Gain is not important since higher than amateur powers are
> >used. So here the LP is a great antenna and the yagi is not.
> >
> >HOWEVER; on 20, 15 and 10, there are 5 element monobanders...
> >Hey: a lot of gain and reasoanable bandwith. For that purpose
> >it is great and the lp stinks!
>
> Yep, for coverage of a few hundred (or fewer if you insist on F/B
> in excess of 20 dB) KHz, a multi element yagi is hard to beat.
> But they are not without their limitations. However on the
> whole, properly designed, installed, and tweaked in situ to
> account for the site specifics, they are indeed the gain kings.
>
>
> >
> >So I guess I'm trying to say what everyone else has been
> >saying... both are great for their intended purpose (assuming
> >they have been built and tuned correctly!!)... and both are
> >terrible when used for a non design intended purpose.
>
> Tuned correctly is a key observation. But it includes a _LOT_
> more than simply having a reasonable SWR somewhere in a ham band.
> Very few tribanders actually end up installed with all of the
> parasitic elements doing what the design calls for on all bands.
> And the typical user has no way (other than the pattern stinks on
> some bands) to determine that something is wrong. And even if he
> does, he has no possibility whatsoever to make the required
> "tweaks" for the affected band and then make the required "tweak
> compensations" to keep the OK bands performing correctly.
>
> OTOH, the LPDA only goes together one way and is somewhat self
> compensating for unfortunate aspects of the site where it is
> installed. They pretty much work as expected even considering
> the large variation in the properties of their surroundings.
>
> This is why Ward and Steve's comparison tests are so useful.
> They are exposing the fact that the tribander's emperror is
> relatively scantily clad. And this is why there has been so much
> controversy surrounding their reports.
>
> For a long time now, we have been choosing tribanders because
> their _claimed_ performance was better than the LPDA's _claimed_
> performance. Now we are forced to compare the tribander's
> _actual_ performance with the LPDA's _claimed_ performance.
> Soon, maybe we will be able to finally compare the tribander's
> _actual_ performance with the LPDA's _actual_ performance. We
> will finally have achieved the "apples only" comparison. My
> guess is that once that is possible, the LPDA will not be shown
> lacking when coverage of 3 or more HF bands is required and
> performance on all the covered bands is insisted upon.
>
> Just my $0.05.
>
> 73, Eric N7CL
>
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>
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