Quote:
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Originally Posted by bobsgarage
Happy Saturday!
I'm ready to do some testing but not sure what to test today!
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Thanks for the image.
The location of the single antenna may be a better location with respect
to multipath (likely ground reflections).
Best current guess; the problem is external and related to height.
Height is often a consideration:
The following graph from posts starting here:
http://forum.tvfool.com/showpost.php...8&postcount=79
illustrates this height effect, to a small degree:
Note:
The graph shows the average signal strength of 27 individual channels combined
versus height.
The heights in the image around 20ft and from 25 to 30 feet
showed evidence of multipath cancellation of signal.
The effects will be different for every location and channel, but is often present.
Mostly the interference comes from a ground reflection (which is delayed
due to longer path) being received simultaneous with direct path signal.
There will be heights where these two signals are in phase and other
heights where the two signals are not in phase.
This graph for three individual channels shows effects more clearly:
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If the horizontal stack were mounted at the location where the single
antenna is located, that could provide more insight.
.