Well -- I have found that modelling gets you in the ball park (an
approximation)
A good SWR meter will allow you to tweak it up.

For 1/4 wave vs 5/8 wave 2M antennas -- I have found empirically -- that
when in an area surriunded by big mountain tops -- like Silicon Valley in
the CA Bay area -- the 1/4 wave works better due to its higher angle of
radiation of the 1/4 wave

When on the open road where terrain is flat and the mountains are far
away -- the 5/8 wave works best -- lower angle of radiation.

This is just my empirical observation --- your radiation angle may vary --
hi hi.

--
Caveat Lector Ya All

"Amateur Radio is the best back-up
communications system in the world,
and that's the way it is." -- Walter Cronkite





"Vito" wrote in message
...
I agree completely. Question is, if modeling and prediction is so
unreliable
why do we bother?

"Dan Richardson @mendolink.com" ChangeThisToCallSign wrote in message
...
On 18 May 2004 06:19:50 -0700, (Brian Kelly) wrote:

Then howcum my 5/8 wave mag mount 2m mobile antenna very significantly
outperforms the 1/4 wave mag mount antenna I used to use? ....

My previous response was for a ground plan antenna mounted above
ground and you are addressing a mobile installation. They are different.

... I found that the vehicle's size, shape and whip location
plays a major part in performance.

.... it was possible to find azimuth directions that a 5/8-wave would
produced almost 3 db gain over itself ....

I don't feel you can accurately predict how a the whips will perform
on a vehicle based upon operation on another vehicle....