Re: [TowerTalk] Inverted Vees

[jimlux <jimlux@earthlink.net>]

On 6/15/20 11:18 AM, john@kk9a.com wrote:
> Also an inverted V does not have the big nulls that a flat dipole has 
> making the inverted V's orientation is less critical.
> John KK9A
>
> Richard (Rick) N6RK wrote:
>
>
> On 6/15/2020 3:55 AM, Rob Atkinson wrote:
> > Inverted Vs are compromise antennas in most cases compared to flat top
> > height of an inverted V is the average between the apex height and the
> > height of the ends.  So a 60 foot high apex with the ends on the
> > ground is pretty much like having a flat top at 30 feet.  All is not
> > lost.  If you can hoist an inverted V up high on say, a 100 foot
> > K5UJ
> The above analysis would seem to be predicated on the assumption of
> uniform current in the wires.  Of course, it is far from uniform, being
> heavily weighted towards the center.  If the current were parabolic
> (as a rough guess), the effective height in the above example would
> be 45 feet, if you want a rule of thumb.  Better yet, model it.
> Takes 5 minutes.
For a full size antenna the current distribution is more like 
sinusoidal, so, without actually calculating, I'd *guess* 2/pi (= 
average value of sin(x) from 0 to pi), or 64%

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