TopBand: Re: Verticals

[Earl W Cunningham]

Hi, All,

Thank you all for your comments re angle of radiation from verticals.

It was pointed out by John, W1FV that EZNEC's ground models may not be
completely accurate (ground losses are probably even greater), and I
agree.

Even though ground wave (zero degree elevation signal) does not exist for
BC stations in the computer world, it most assuredly does in the real
world (of non-perfect ground), as observed by Tom, W8JI.  (Because this
observation seems to be contradictory to W1FV's statement, it provides
food for thought.)

Some commented about "higher angle of radiation" over poor ground.  Not
so! "Higher angle of MAX radiation" is more appropriate.  Over poor
ground, the lobe is basically the same, but the low side of it is greatly
attenuated.  This is known in some circles as "suckout".

While I mentioned that a lobe with max radiation at a very low angle also
has much radiation at more useful (160 DX) higher angles, VE7BS points
out that the contrary is also true - those "cloudburners" still have much
radiation at more useful (160 DX) lower angles.

Some commented that their 1/4-wave vertical was superior to taller
verticals.  Let me reiterate my experience: I used a grounded 1/2-wave
vertical in Houston/Gulf Coast area where the soil conductivity is
abnormally high.  It was a super performer.  The same vertical here in
the desert was a ho-hum performer, even with a much more extensive ground
radial system.

Antenna modeling software is a great tool, but performance in the real
world is what counts.

73,
  de Earl, K6SE

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