[TowerTalk] Re: gain specifications (was CobWebb antennas)

[corneliuspaul at gmx.net]

Very well said Mike,


unfortunately it is a true work of art in confusing customers
and claiming gain that is simply not there .. while at the same
time keeping a door open to always withdraw from false
statements.
Which really is a pity because for what it is (a folded multiband
dipole) I am sure this antenna will work quite well !!


Oh my.
When will we finally come to honest gain specifications?
Several honest manufacturers do it, but still more don't...

To get better judgement over those claims I can only urge
people to

- read the tribander comparison report by K7LXC / N0AX
- and check W4RNLs attempt at defining the UPPER limits
of what is possible for 2 or 3el Yagis by the laws of physics.
(Its called "some pitfalls of careless dBd-ing: http://www.cebik.com/dbd.html)

How about putting together a website that deals only with this
subject and expands those definitions by W4RNL further, thus
aiding people into better judgement of false claims?

73,
Con DF4SA




--- W4EF wrote:
>I don't know. He seems to shift at random between measurement
>references. First he compares his antenna measured over
>ground to an isotropic reference, then he compares a straight
>dipole over ground to dipole in free space (not sure how he
>got 5dB though). The whole point seems to be to confuse a
>potential buyer into thinking that somehow his antenna has
>more gain than a beam or even a straight dipole. This doesn't
>inspire much confidence, which is too bad because I think
>all-in-all, it is a fairly sound concept for a compact HF antenna
>- horizontal polarization, reasonably omni pattern, decent
>efficiency, and small size.



--- W8JI wrote:
> > A few things at that site seem to be unclear, such as the
> > statements about gain of dipoles and Yagis. I don't know
> > what he is trying to say when he says a 2 element antenna
> > with 4dBd gain has less gain than his compact antenna with
> > 2dB gain. It is not clear to me what he is saying.