----- Original Message -----
From: alsopb <alsopb@gloryroad.net>
To: <towertalk@contesting.com>
Sent: Sunday, October 03, 1999 3:03 PM
Subject: [TowerTalk] Tennadyne
>
> Guys,
>
> Tennadyne has a web site http://www.tennadyne.com
>
> They have some good reading from the manufacturer
> explaining how gain is indeed sacrificed for
> bandwidth. Unfortunately they ruin the discussion
> with a testimonial which puts one of antennas 5 to
> 10 db above a popular tribander. (Implying thier
> gain approaches 15db!)
Or maybe it just implies that the other antenna has a lot less gain than the
other manufacturer claims it does (loss due to traps, etc). Also if (as
stated here previously) a yagi is "more particular" about enviroment than a
log is, isn't it in the relm of the possible that the log in that particular
enviroment may actually be a much better performer---even if the yagi has a
higher gain figure in free space?
> I can't possibly see how a T6 "kicks butt" as one
> testimonial here put it.
Compared to wide spaced mono-banders, of course not (unless we're dealing
with particulars of enviroment here again). But compared to other simmilarly
sized (less than a 15 foot boom) multiband beams, especially some trapped
ones, I'd believe it.
> It is interesting to note that the claimed gain
> figures show 5.1 dbd for the 12 ft boom case (no
> frequency stated) and 6.5 dbd for the T12 30'
> case. I compared this to W2PV's gain vs boom
> length correlation (yagi's) for the case of 20M.
> For these relatively short booms Lawson's
> correlation shows an increase of more than double
> this 1.4db going from a 12' to a 30' boom. It
> seems that the LPDA has very little gain
> improvement for going from 12 to 30'. I wonder
> just what one does get for the extra 6 elements,
> 18 foot of boom and $500?
I *think* the advantage you get is more consistant F/B and gain on the low
ends of the frequency range. This is based on what I've plugged into my
computer, and what I've read other places.
Lou AC0X
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