[TowerTalk] Cage Dipole Performance

[David Gilbert]

In response to N3OX's posting on cage dipoles, I searched around to find 
more information on them and happened to find the website of a 
manufacturer who also claimed better performance than a standard 
dipole.  I have no idea whether or not this is the same one who had 
corresponded directly with N3OX, but I decided to write this 
manufacturer directly to see how they derived their claimed results in 
order to better understand the design in general, and in particular why 
modeling programs like EZNEC don't properly deal with a cage antenna.

I received a very quick response from one of the owners of the company, 
and since this person states he is aware of the thread here on 
TowerTalk, as well as my own personal skepticism,  I am taking the 
liberty of forwarding his comments verbatim (cut and paste ... no 
editing whatsoever on my part) so that his side of the discussion may 
get fair representation. 

I won't divulge the name of this manufacturer so don't bother to ask.  I 
also think it best if I personally make no further comments in this 
forum, either supportive or critical, on the topics of field testing or 
time diversity in modeling.  I will say, though, that I hear as well as 
my neighbors.

73,
Dave   AB7E


<quote>

Sure the antenna was tested on an antenna range vs a standard resonant dipole. An independent engineering company srt up the trst doing firld intensity measurments in all planes at all practical distance using hewlett packard spectrum analyzers that are capablr of .1 db resoution.
The antenna was tested at distances of 1,5,and 10 miles. The antenna was rotated to check all lobes. Reference data was compared at 15 degree intervals. Antenna height was 1/4 wave and tested again at 1/2 wave. results were surprisingly good. In all cases the cage exceeded the standard by 5 db or better...We were surprised ourselves. However the company used assured us of the correctness of the measurements. They commonly do proof of performance testing for broadcast and cable. Their instrumentation is current calibration and correctly used by experienced engineers.
Standard modeling programs are based on assumption of single piece radiators and have no provision for time diversity in them. The cage uses this phenomina. When one uses most modeling programs, the results err due to this fact. The field data reflects the differences.
I have read your tower talk posts and hope you are amused. The fact is still that the damn thing actually works as advertised..LOL!
The cost of this testing was not cheap. We chose to do it because we are sincere in our desire to provide a first rate product. The guarantee we give on this product is 100% sarifaction or your money is refunded less our shipping..So you risk less than 25 bucks to try one...To this date, 486 units in the field with no returns and no complaints ..NOT EVEN ONE....
 That to me is the greatest endorsement..Satified clients.
Most of the detractors we have spoken with have never used a cage of any design and certainly not ours. We also have found they are too cheap to take our challenge and try one even if we agree to pay shipping back. They basically have their opinion..And that is "if I can't afford it it must not be any good". With our warranty there is no risk to try it! Now would we do that if we had no confidence in our products. I put my money where my mouth is daily. HOW ABOUT YOU! Or are you a person who buys a $3000.00 radio to use as $20 dipole for an antenna and then bitch because the rig isn't hearing as good as your neighbors.

</quote>