TopBand: high angle at dawn

[w8ji.tom]

 Hi Bob,

> As sunrise approaches, the horizontal loop begins to hear the VKs better
> than the vertical half-diamond.  If the signal goes into a deep fade, it
is
> almost always strong when I switch temporarily to the half-diamond. I
don't
> know whether that is polarization or change of arrival angle.

I see the same effect, from moment to moment one antenna or another will be
better IF one antenna is in a fade.
 
> Receptive as I am to calculations or measurements that confirm my
intuition,
> Earle's figures comfort me no end. If the bottom of the lobe of my
> cloudburners can approximate the top of the lobe of the beautiful
monopoles,
> I can sleep peacefully.

But beware that the TOA of a vertical almost certainly is not correct.
Remember the programs Earl (and many of us including myself)  use calculate
pattern at a very long distance over flat earth. Using that method, any
amount of loss in the media supporting ground wave signals produces nearly
zero field strength along the ground. We know that pattern isn't true at
distances that compare to the height of the ionosphere on 160!

We have to be exceptionally careful when using a bunch of unknowns to reach
conclusions others will depend on as facts.

My results parallel other results, the horizontal or higher wave angle
antenna is better at or after peak on most days when there is a peak. It
just isn't much better than the verticals I use, and isn't near as good
prior to peak at any distance more than a few hundred miles. The vertical
performance differences could very well be tied into antenna efficiencies
or less than ideal patterns rather than other differences.

There is little question in my mind a horizontal is a more forgiving
antenna for less than ideal sites or ground systems.

73 Tom

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