[TenTec] Re: ~ 1/4 wave 160 doublet
Ken Brown
ken.d.brown at verizon.net
Tue Oct 21 21:08:33 EDT 2003
Hi again Jim,
I live in Hilo and use and inverted L on 160 meters. The vertical
section is only about 40 feet long, the rest is approximately
horizontal, rising up to about 50 feet and then dropping down again to
maybe 35 to 40 feet. The whole thing is a quater wavelength (I trimmed
it to resonance, which I realize is not necessary, but I like it that
way). I have about 30 radials coming out from the base feedpoint. The
radials cover less than 180 degrees around the base since the base is
pretty near the property line. I hear the fish net becaons and have also
not worked any of them. I also work a lot of mainland stations, mostly
West coast and occasionally work VK, ZL, JA or some kind of Carribean or
Central American.
As you are well aware there are not too many short haul stations to work
from Hawaii, especially not on 160 meters. So you are best advised to
try for good low angle radiation. That means either a very high (half
wavelenth or more) above ground horizontal antenna, or a vertical with a
good ground system. Sounds like you (and me too) can forget about the
horizontal option, so that leaves the best vertical system you can
muster. I think in your situation if you just cut the ladder line at the
point here it starts going vertical and feed it there as a tee top
loaded vertical, you could do a real good job on 160. Maybe have a
remote tuner there, or some kind of remote switch arrangement to select
between T top vertical and ladderline fed dipole modes.
To all those who have good results with low horizontal antennas: I do
not deny that they can work. It is just that the antenna books and
modeling programs say that for low angle radiation you're better of with
a vertical (if you have a good ground system)
73 ES ALOHA DE N6KB
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