View Single Post
  #29   Report Post  
Old May 5th 07, 04:58 PM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default Gaussian cluster antenna array data

On Sat, 05 May 2007 00:20:08 -0700, Roy Lewallen
wrote:

Anyone who's impressed with the gain figure of either antenna should
model a dipole at the same height for comparison.


Hi Roy,

A useful suggestion. Having a reference is always the point to start
from.

Another option, as for all of Art's designs, throw away half the
elements to improve performance.

Easier yet, simply pull up a design that has been around 80 years
(found in most books on the subject of Antennas), the Yagi. Case in
point (and illustrating my comment about throwing away three of those
six wires) is available without thinking, designing, or going to the
library: simply use the free version of EZNEC and open NBSYAGI.EZ.

To make it comparable to the description that has taken a dozen
postings to sort out:
1. shift the units to inches (makes absolutely no difference on the
original design);
2. shift the frequency, along with a rescale, to 14.25 Mhz (makes
absolutely no difference on the original design);
3. raise the antenna by 1400 inches (makes absolutely no difference
on the original design);
4. change the ground type to perfect (makes absolutely no difference
on the original design);
5. change the plot type to 3D (makes absolutely no difference on the
original design);
6. change the Step Size to 1 degree (makes absolutely no difference
on the original design).

Now, to enjoy the rewards of the triumph of truth:
1. press the FF Plot
2. press the show 2D plot

Results:
Gain: 15.58 dBi
toa: 8 degrees

Differences?
MORE GAIN THAN THE INEFFICIENT GAUSSIAN BUNDLE
LOWER LAUNCH ANGLE THAN THE INEFFICIENT GAUSSIAN BUNDLE
HALF THE ELEMENTS OF THE INEFFICIENT GAUSSIAN BUNDLE
SIMPLER TO CONSTRUCT THAN THE INEFFICIENT GAUSSIAN BUNDLE
THEORY AVAILABLE, NOT SO WITH THE INEFFICIENT GAUSSIAN BUNDLE
DESIGN IS FREE, NOT SO WITH THE INEFFICIENT GAUSSIAN BUNDLE

[no Gauss were harmed during the analysis of these antennas]

73's
Richard Clark, KB7QHC