[Lowfer] Fenceline longwire

[Zack Widup]

VHF antenna design is one of my favorite areas of experimentation.  I have 
used Yagi Optimizer heavily over the years.  That, coupled with MININEC, 
tells me if a design is going to work well.

Since I like to operate VHF from portable locations, I try to squeeze as 
much gain out of as few elements as possible so the antenna can be made 
light and compact when disassembled, and quickly assembled at the site. 
Gain is related to the length of the boom more than it is to the number 
of elements in a Yagi. A lot of people don't know that.

I've been experimenting with long-spaced Yagis.  I came up with a design 
for an 8-element 2 meter Yagi on an 18 foot boom that should produce 13.0 
dBd gain in the forward direction. I really don't care about F/B ratio in 
this design as much as the tradeoff between forward gain and feedpoint 
impedance (another important factor).

I always double-check the design produced by Yagi Optimizer with NEC or 
MININEC because on rare occasions they disagree on results.  Usually the 
MININEC is correct.  If they agree fairly closely, I build it and it 
meets my expectations.

73, Zack W9SZ

On Mon, 21 Jan 2008, Andy Bell wrote:

>
> --- "J. B. Weazle McCreath" <weazle at hurontel.on.ca>
> wrote:
>
>
>> Thinking outside the box can sometimes yield a
>> surprising
>> result, if that's the only option you've got!
>
> Hello J. B. and all:
>
> My personal opinion only: When we loose the
> pioneering / experimenting spirit of the Amateur
> hobby, we can easily become as stale as the riceboxes
> we operate. pre-programmed with the idea that this is
> the best, and we can't do any better. As one licensed
> operator ( don't really want to call him a ham
> )running a shack full of commercial equipment and all
> commercial antennas told me: " you can't build a
> better antenna than what you can buy; why don't you
> quit wasting your time, spend the money, and buy you a
> good antenna." I ended up building a 24 element 2
> meter longboom that with 10 watts output was running
> 20 over 9 signals 120+ miles down the road, all for a
> grand total of $ 40.00. He didn't like to talk to me
> aftwards. To those with the pioneering spirit: Keep up
> the good work.
> 73, all: and thanks for the moment on the soapbox.
> Andy Bell - KU4XR
>