[TowerTalk] Vertical question

[Dave Sublette]

Good morning,

I recently changed my elevated 160 meter quarter wave vertical with 8 full
sized radials to having only 1/8th wave length radials and only four of
them.  It is working great.  So I thought adding four more radials might
improve things.

But before I went to all the trouble I decided to model it and see if there
was a difference in performance of the 8 radial version compared to the 4
radial system.

I use a modelling program called Antenna Model.  The result of the
comparison is this:

The 4 radial system showed a gain of 0.92 dBi with the main lobe at an
elevation of 20 degrees.

The 8 radial system showed a gain of 0.93 dBi and an identical elevation
pattern.

My question is:  Why is the gain figure so low?  A dipole exhibits 2.14 dBi
gain. Why doesn't the vertical show gain?

And lastly, I think these results tell me it isn't worth the effort to add
four more radials.

Your thoughts?

Thanks & 73,

Dave, K4TO