> inverted vees, supported by one center support. The reason
being, it is
> difficult to get this antenna very high. Maybe I should
not have made
> that assumption. If you put this antenna at or above about
80 feet, it
> does have decent low angle performance, but this requires
four or five
> 80 ft supports, for a flat top, which most people don't
have.
I was speaking about a bowtie. I use a pair of smaller gauge
wires fanned out to a spreader made from 1/4 or 3/8th inch
aluminum tubing. I connect wires to the tubing. A ">"
shaped rope harness ties the spreader ends to a common
support rope. The capacitance from the spreader at the
outer ends shortens the required length for resonance.
As for inverted Vee dipoles, they show pretty good
directivity at higher heights. The main change is the
drooping reduces effective height a bit. My 160 meter
inverted Vee dipoles, at 318 ft apex height, were typically
down 15-20dB off the ends. Same for my lower 80 meter
inverted Vee dipoles, which were at 160 feet apex height.
Standing on that tower at 250 feet, you look out about level
with the ends of the inverted Vee dipoles for 160.
http://www.w8ji.com/my_shack.htm
It typically made about 4 or 5 S units difference in JA when
I used the inverted Vee dipole broadside to Europe rather
than one broadside to JA.
73 Tom
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|