At 5:11 PM -0500 10/9/02, hasan schiers wrote:
>...the important thing to remember is that any dipole style antenna,
>when...appreciably longer than a half-wave, do[es] not respond
>favorably to being installed as [an] inverted vee....
Thank you for making this important point, although "any" may be a
slight overstatement. You are correct that, if an antenna is more
than a half-wavelength long, then bending it (e.g., into an inverted
V) can do surprising and often unwelcome things to its pattern.
Fortunately, the consequences of bending can be predicted by computer
modeling.
I'm not sure that I can remember reliably where this thread began,
but I believe that it was about the G5RV as an 80-meter antenna -- in
which case the G5RV is _less_ than a half-wavelength long so little
can happen to its pattern. On 40 meters there's not much to worry
about, either; but on 30 m a G5RV is one full wavelength long; and
things get more complicated for shorter wavelengths.
It turns out that a regular G5RV is a very good antenna for 20, 17,
15, 12, and 10 meters *if* it is configured as an inverted
rectangular "U", or |____|, with its central 20 meters horizontal and
5 meters hanging vertically at each end. I discovered this
configuration via NEC-4 simulations a few years ago, built it, and
have been using it ever since. This configuration, discovered
independently, was described in an article that won the QST "Cover
Award" this year.
73 de Chuck, W1HIS
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