TT:
I finally found it after searching for a couple of days - an article I
uncovered in 1998 on theory and design of LPDAs. Well worth the read.
http://www.salsburg.com/Log-Periodic.pdf
73 de
Gene Smar AD3F
----- Original Message -----
From: "Kelly Taylor" <ve4xt@mts.net>
To: "Joe Subich, W4TV" <lists@subich.com>; "[TowerTalk]"
<towertalk@contesting.com>
Sent: Friday, February 25, 2011 9:24 AM
Subject: Re: [TowerTalk] book Tribander comparison test
>
>>
>> That's an excellent *joke*. Only a very small portion of the boom
>> length of a log-periodic is active on any one frequency typically
>> around 25%. This leads to the log periodic having more than 3 dB
>> less gain that a well designed yagi of the same boom length.
>
> As someone who is considering a smaller HF antenna for the cottage, I find
> this discussion quite interesting.
>
> I'm struck by Joe's assertion regarding LPs. And I say that only because
> if
> you compare F12 gain vs. Steppir gain, they seem quite similar for
> antennas
> of similar boom length. And when you adjust Steppir's and F12's dBi to
> compare to Tennadyne's dBd, again, they all seem within a hair of each
> other. And then you add in the raves that Tennadyne gets from owners, even
> from relatively knowledgeable owners not given to self-aggrandizing their
> purchases, and I still seem to lean towards Tennadyne's combination of
> performance, F/B, price and simplicity.
>
> (I say all this fully cognizant that advertising is advertising and that
> figures lie and liars figure, but even Steve has said Steppir and F12's
> gain
> figures are relatively trustworthy. I also concede the advantage of
> tunable
> elements.)
>
> I haven't bought anything yet, so I'm still open to discussion, but keep
> in
> mind that in my case, the budget is NOT unlimited.
>
>
> 73, kelly
> ve4xt
>
>
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