I am planning to build an elevated 60 foot vertical antenna for 30/40/80 =
and 160meters to hoperfully improve my signal on these bands. Will it =
help to also put up a beverage for receiving? Any and all suggestions =
will be appreciated. =20
I have a metal barn that is 50x90 feet (which should completely =
eliminate any need for radials) and is 16 feet high. I plan to put the =
vertical in the center and insulate the base from the roof. The roof =
consists of 60 galvalume panels 36"x26 feet bonded by screws every 4 =
feet.
Has anyone done this before and any ideas about the size of aluminum =
tubing necessary to survive 100 mph gusts in Texas thunderstorms? =
(Planning on 2 inch at base (because 3 inch is more expensive) and maybe =
all the way up, but will have 2 joints to deal with-suggestions welcome)
160 mtr will require a loading coil with fairly high q and wire size. =
80 mtr should be a 1/4 wave and feed directly with 50 ohm coax 40 mtr =
should be a 1/2 wave and will require a tuned circuit and tap =
arrangement to get 50 ohm feed and I have no idea how to do this.
30 mtr may be able to feed as a 5/8 wave and will also require a tuned =
circuit and tap arrangement similar to the 40 mtr.
The power level will be 1500 Watts PEP or cw. What is the best way to =
guy it so that maintenance is low.
Plan to have a relay switch box at base to select the band and then coax =
feed it through lightning arrestor or some kind (located either at base =
or where coax goes into underground pvc conduit to hamshack.
I have also considered putting up 2 of these on the 50x90 metal barn but =
I don't know what spacing would be optimum for a multi-band vertical or =
even if it is worthwhile.
This qth is a hilltop location with the surrounding terrain sloping down =
at about a 2 degree slope for a mile or so (This helps horizonally =
polarized antennas, but what does it do to verticals?). The top of the =
vertical will be approximately 76 feet high (22 feet higher than the =
tower located at the house) and I am concerned with how to best protect =
the antenna and the hamshack (300 feet away) from lightning.
I guess there are two ways to go about this. One is to experiment with =
loading until you get it right and the other is to model the vertical =
and calculate at least a starting point. Has anyone modeled a vertical =
like this before and would be willing to share their input file, etc.? =
Has
anyone built a similar vertical and would provide the details?
--=20
Wendell Wyly - W5FL w5fl@flash.net
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