Lostgallifreyan wrote:
John S wrote in :

Something else might be interesting; include the effects of sag
(centenary) in a wire antenna.

Agreed. I was thinking about that possibility last night. Meaning 'catenary',
perhaps? As in 'hanging chain'? I doubt any longwire would lack this, so
modelling it would be useful.

I doubt you will see any significant difference.

I've done a lot of modeling with V's and inverted V's. Except for a slight
diffenence due to ground effects at low heights, there is no difference
between them.

As the angle goes from 180 degrees, i.e. a dipole, the impedance goes
down and and the pattern spreads out.

As the angle gets smaller, the gain goes down, the pattern becomes almost
circular like a vertical, and the antenna starts looking like a transmission
line, which it becomes when the angle gets to 0, with some spacing between
the wires of course.

And like an ordinary dipole, height over ground has a major effect on
the pattern.

Example: At 108 degrees, the impedance is about 65 Ohms and the broadside
null of the dipole is now only about 7 dB down from the main lobe.

But as the inverted V is a popular antenna, the pattern with common
leg angles would be instrutive.



--
Jim Pennino