Topband: 5/8 wavelength vertical is mo betta than shorter versions??

[Charlie Cunningham]

???

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Richard
Fry
Sent: Friday, September 27, 2013 7:27 PM
To: topband at contesting.com
Subject: Topband: 5/8 wavelength vertical is mo betta than shorter
versions??

Niko AC6DD wrote:
>... the 5/8 Vertical idea came from the "All About Vertical Antennas" Book.

>Getting 3dB with some wire and a balloon sounded pretty good.
____________

The approximate 3 dB improvement of the radiated field of a 5/8-wave 
monopole compared to a 1/4-wave monopole refer only to the maximum fields 
they radiate, NOT to the fields they radiate at  __all__  elevation angles.

Those maximum fields always occur in the horizontal plane, regardless of the

vertical monopole radiator length/height, and/or the conductivity of the 
earth within a 1/2-wavelength radius from the base of that monopole.

This may be confirmed by referring back to the FCC document linked earlier 
in this thread ( 
http://s20.postimg.org/olcquv94d/Monopole_Elev_Patterns.gif ).

For 1 kW of applied power, the groundwave field radiated by a perfect 
1/4-wave radiator over a perfect ground plane is about 195 mV/m.  For those 
conditions using a 5/8-wave radiator, the field at 1 mile is about 275 mV/m.

Other things equal, this field improvement in the horizontal plane for a 
5/8-wave vertical monopole relative to a 1/4-wave vertical monopole is very 
close to 3 dB.

RF 

_________________
Topband Reflector