TopBand: Elevation Angle of Maximum Radiation

[Bill Hohnstein]

I'll speak of on-air results and let others more knowledgeable than I
speak of the theoretical explanations behind it:
  One antenna is not the perfect antenna for everybody...  I've had
good luck with low angle transmit antennas--my 160 meter parasitic
vertical array transmit antenna last season had peak radiation at 16
degrees above the horizon towards Europe (or South Pacific when beaming
in that direction).  Improving one parasitic element this summer will
decrease that to 15 degrees and increase the antenna's gain by 1.3 dB.
  While the radiation is not that much down up to 40 degrees above
the horizon, I think that I've worked some DX stations when others 
with higher angle radiation antennas have heard nothing...
  Many people have problems with 1/2 wavelength antennas because it's
more difficult to efficiently match the high impedance of those 
antennas with high power.  Anybody who has significantly better
performance with a 3/8 wave vertical than with a 1/2 wave one is
probably experiencing the problems due to reasons other than the
slight decrease in the angle of radiation.
  Within 2,700 km of here I can work a grand total of 3 countries
(and two of them are of little value in the ARRL DX contest).  I
would have a different primary antenna if I were located in Europe.
  My 40 meter antenna has a 5/8 wavelength vertical driven element.
While it's a different game in several respects there, I've had
good luck with it on that band [Japan worked at 1802z (12:02 pm local)
short path on 40 meters on 16FEB97 (after most of the west coast
left the band)].
  There are times when I envy a higher angle transmit antenna.  There
are better low-angle antennas (particularly on 40 meters.  But, I
think that I've had pretty good luck with a transmit antenna with
a low angle radiation on 160 and the low bands in general...

73,  Bill     K0HA


--
FAQ on WWW:               http://www.contesting.com/topband.html
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com