For an 80M inverted V with the apex at 90 feet, ends 10 feet above ground,
and an inside angle of about 90 degrees, EZNEC+ 6.0.6 calculates -3.47 dBi
gain at a 15 degree takeoff angle. Moving the ends up to 30 feet above
ground improves the gain to -1.67 dBi at a 15 degree takeoff angle - a
little less than 2 dB improvement. Moving the ends up to 35 feet above
ground increases the gain to -1.31 dBi. That's more than a 2dB gain
improvement at a 15 degree takeoff angle over the ends at 10 feet above
ground. Tom N6BT wrote in his book that "the amount of difference in an
antenna system that makes a significant performance difference....is 2 dB".
73,
Marsh, KA5M
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
Robert Harmon
Sent: Thursday, August 27, 2015 1:44 PM
To: Ham - Tower Talk
Subject: [TowerTalk] 80 meter inverted V
I have an inverted V strung from my tower for 80 meters. The apex is at 90
feet and the ends are supported by 10 foot poles at the corners
of my property. The inside angle of the V is about 90 degrees. I am
considering extending the poles to 30 feet high which would make the
angle about 120 degrees. For DX do you think this would be worth the effort
? The radiation pattern has to be improved but but maybe not
that much ?
Bob
K6UJ
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|