[Antennas] gain vertical

[CBoone]

Take a balloon.....put it between two plates and then push them slowly
together...see how the balloon bludges out at the center? That's the gain in
a vertical gain antenna..you are lowering the angle of radiation from the
center of the array...(like squashing a donut!).....but there is a trade
off...if you have a high gain vertical antenna high in the air, the signal
can actually suffer nulls close in because of the narrow pattern.
 

> -----Original Message-----
> From: antennas-bounces at mailman.qth.net 
> [mailto:antennas-bounces at mailman.qth.net] On Behalf Of 
> fkamp at comcast.net
> Sent: Friday, April 22, 2005 12:31 PM
> To: antennas at mailman.qth.net
> Subject: [Antennas] gain vertical
> 
> I just built and installed a vertical collinear for 2 meters. 
>  Two half waves.
> 
> It is touted to be an omnidirectional gain antenna.  This 
> thing works well.  Much better than the 1/4 wave ground plane 
> I was using at the same elevation.
> 
> Then I got to wondering.  I understand how a beam works.  You 
> get gain in one direction because the signal is 'directed' 
> toward the favored direction.
> 
> I am not sure where the gain comes from in a vertical gain 
> antenna.  It is still omnidirectional.  Seems the only thing 
> it plays with is take-off angle.  I dont see how that 
> translates to gain.
> 
> Regards,
> Frank Kamp
> K5DKZ