[TowerTalk] Antenna Peformance vs. Height and Elevation

[T A RUSSELL]

Antenna Peformance  vs. Height  and  Elevation    de   N4KG

>Hi Pete. Also, who is higher in elevation, etc. I have 3 elements on 20 
>at 35 feet and a friend has 4 at 60 feet and I'm consistantly beating 
>him out. But the location here is about 400 feet higher. 73
>Tom W7WHY
>

Tom -

I respectfully disagreee.  Elevation alone has nothing to do with antenna
performance.  An antenna at 60 ft above a flat reflecting foreground at
2000 ft elevation will have an identical pattern in the vertical plane as
an
identical antenna at 60 ft above a flat reflecting foreground at 500 ft
elevation.   TERRAIN and a sloping foreground on the other hand
can have significant influence on antenna performance.

Regarding antenna HEIGHT above a FLAT GROUND, 
HIGHER   IS   NOT   ALWAYS   BETTER.  Often, higher angles produce
stronger signals than lower ones, especially if the MUF is well above
the operating frequency (this is particularly true on 20M) and the other
station is also using a low antenna (as is most often the case for DX
stations).  If the ionosphere will support waveangles up to 20 or 30 
degrees and the distant station has a low antenna, he will be radiating
more energy at the higher angles than the lower ones.  A receiving
antenna that matches the angle with the most energy (most likely
one of a similar, usually lower, height, will be the best antenna to
transmit back to the distant station.   During mid-day when the
MUF is high, my 40 ft TH7 often beats my higher monobanders
to Europe and Africa.  (AND, of course, all of my towers are at
nearly the same elevation above sea level.)

OLD   MYTHS  NEVER  DIE  ....   HIGHER  is NOT  always BETTER

de  Tom  N4KG



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