Topband: Another DXpedition 160 Vertical Idea
John Tait
bravo at iol.ie
Fri Jan 28 12:36:29 EST 2005
Larry Higgins said:
> However, it is also true that vertical dipoles do induce current in the
> ground, and the energy transferred to ground comes from the transmitter.
I've seen this warning many times, but when I actually compared a half
wave vertical with no radials to a quarter wave vertical with
32 radials, the difference was too close to measure (ie less
than 3 dB). This comparison was done on 20 meters, so we can't
be certain that the results would hold on 160 meters. Still, it
does suggest that the losses aren't all that high.
Rick N6RK
That has also been my experience Rick....Even on Top Band. My
traditional ground mounted, base and centre loaded 50ft vertical, with about
45 60ft, and a dozen or so 130ft radials, was NEVER better than my vertical
dipoles (as per Rudy N6LF's QEX article) on 80 or 160m. The actual radiating
portion of my dipoles are only 45ft long, the highest point is about 60ft,
and the bottom capacity hat wires are about 15ft off the deck.
Yes, they'd work better with a ground sytem underneath, but they're very
quick and easy to deploy, are two dimensional, and effective.
They're at http://www.iol.ie/~bravo/low_band_antennae.htm if anyone's
interested.
John EI7BA
More information about the Topband
mailing list