Richard wrote:
Hi. I'm wanting to "design" using a "simple design methodolgy". As far as I
can tell that means avoiding using models and antenna programs because I
think designing a practical yagi from a model is *not* a simple design
methodology. That's my impression.
So I think the best option I have is to take a practical design and use the
principle of scaling, and using a program that will make adjustments to the
element lengths for an alteration in element diameters and a program that
will make adjustments in element lengths for alteration in boom size. I'm
pretty sure element spacings will need not to be altered given some
reasonable alteration in either element diamters or boom size.
(Do these correction programs assume a particular element fixing method I
wonder!!. Where are these programs. I only know of ELE.EXE)
I'm looking for a practical design that uses a hertz dipole as DE, not a
folded dipole. And it ought to be wideband well, a bandwidth of about 4% of
the center frequency.
Boom needs to be metal.
I'm looking to make the center frequency 159 Mhz. So any practical design I
suppose is likely to be a VHF yagi not too far removed from 159 Mhz.
There can be a balun arrangement or not, but I don't want to feed a balanced
DE with unbalanced coax.
My antenna is to be a receiving antenna.
My email is:
Please remove REMOVE.
Thanks.
There use to be a program available written by Gunter Hock, DL6WU, that
was for designing VHF/UHF yagi antennas. It took into account boom type
and size, element size, bonding methods, etc.. The original program was
written in BASIC. For my own use, I converted it over to a JavaScript
driven web page. If you are interested I just posted it on the web at
http://www.k7mem.150m.com/Electronic.../yagi_vhf.html.
Maybe this is the kind of thing you are looking for. The original BASIC
source code is available.
I only started this web site a week ago so don't expect everything to
work completely. There are several known links that really don't go
anywhere yet.
--
Martin E. Meserve