> > 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?
This is why I have asked here for more data about the environmental
issues for each type of antenna. Note: We have mostly been discussing
the Tennadyne T-6, 7 & 8's versus the Force 12 C3 & C3S, so the trap issue
is not relevant and the boom lengths are similar. This eliminates some
variables
for clarity.
> > 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
We are making progress ... K1YP
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