[TowerTalk] horizontally polarized antennas and salt water

[Pete Smith]

At 11:21 AM 1/18/2005, Jim Lux wrote:

>Pete Smith wrote:
> >
> > It does, but not a bunch.
> >
> > I quickly modeled a 40m yagi at 104 feet over average ground versus salt
> > water.  Forward gain went from 11.86 dBi (avg) at 18 degrees to 12.45 dBi
> > (salt).  Takeoff angle, interestingly, went up one degree for the better
> > ground plane.  Moving the antenna down 6 feet over salt water moved the
> > takeoff angle up 1 more degree, from 19 to 20 degrees.
> >
>
>Just as an idle question..  I wonder if the gain change is due to a pattern
>shape change (narrower main lobe), or due to a reduction in losses. The
>average gain number would tell you, since it's integrated over all look
>angles.

It appears to be reduced losses.  The average gain over salt water is -0.06 
dB; over average ground it is -0.96 dB, per NEC-2.

73, Pete N4ZR