On Jun 18, 10:36 pm, art wrote:


Come on Art, you won't give away a million dollar idea if you publish
the construction details of an 8 foot long 3 element 20 meter beam. You
will be able to squash anyone like a bug with your 30 foot version.

tom
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No,No.No. The criteria used by the arrl woulod not allow me to do
that.

What does the ARRL have to do with anything?
Besides, they are just a bunch of lowly amateurs..
According to you, the likelyhood of them understanding a
word you say is slim..
I agree really, but fer different reasons... :/

I never go below 20 ohms so I can use a 2:1 balun.
Actualy I just added another element to make it 4 el on a 8 foot boom
I havent finished it yet but at the moment it is around 40 ohms, less
than 2:1 swr
F/B is 30 db worst case and the gain is about 1/2 db more than the
three element.

F/B is easy to get with a short boom.. Big deal..

The elements are std length as per a yagi but bent a bit so they
are all in equilibrium.

I love it when you talk like that...There is something about the word
"equilibrium" that reminds me of Pleasant Valley®.. Where all is
at peace in the universe, and the skies are not cloudy all day...
We can all sit around the campfire and sing, home, home on the
range! Where the fractals and the gaussians play!
Where seldom is heard, a coherant word, and I'll probably wanna
stay drunk all day!
That way I can fit in better..
Well, I digress... back to the jibber jabber at hand...

Tom what you don't
realise
is that the boom length on a Yagi is to focus the main lobe, it does
not
supply an increase in actual radiation so getting 11dbi with a 8 foot
boom
is no big deal as the gain is limited regardles of boom length or
elements used.

This is the statement which drew my attention.. Shame on the mess...
You think I can't get more than 11 dbi with a yagi? I've got models
of some for 70 cm that do 17 dbi, and I haven't even manually tweaked
them yet.. I can make ones that do more too..
The addition of gain does not stop at some specific boom length.
It does decrease bit by bit as you add each element, but you can
sure get a lot more gain from a yagi than you advertise.
And adding more boom length and elements does add more gain ,
although the payoff diminishes to the point where it's not worth
doing for a single antenna. They start stacking them when they
get to that point.
You keep talking about these short boom things and acting like
there is no more gain to be had by adding more elements..
That #$%@ ain't right, as the song by the Saddlesores goes..
MK