I've built a 40m vertical dipole for FD, bottom fed with a good choke
(actually 2 big clamp ons worked better) to isolate the feedline.
Worked fine, interestingly a great match to 75 ohm coax which it was
made from, including the feedline. About the easiest, fastest up,
stealthy, and good omni antenna.
A 132ft dipole for 80m is a bit of a challenge even with the monster
firs around here. Shortening it with coil loading makes the whole thing
trickier to make for hanging in a tree.
If 40m is of interest Steve, it's here to borrow, just add the clamp- ons.
Grant KZ1W
On 10/20/2020 11:10, amfone via TowerTalk wrote:
But if its a vertical positioned dipole it does not need a counter poise or
radials as its a dipole. A vertical dipole has a pattern and low take off angle like
a true vertical but the feed line must come away from the center at a 90 degree
angle for best performance for several feet.
Also a ground plane is a great antenna for low angle of radiation. To be a true
ground plane the radios should be off the ground at least 1/8th wave but if you
can't do that any height above ground will work. The best thing is that 3 or 4
above ground radials 1/4 or 1/8 wave length long will work as good as 100
buried radials. This antenna is simple to make just hange some wire, its easy
for bands 40 meters and up and if you have some really nice trees 80 and maybe
160..
73 Tim
WB8UHZ
On Tuesday, October 20, 2020, 1:49:50 PM EDT, Jim Brown
<jim@audiosystemsgroup.com> wrote:
On 10/20/2020 9:42 AM, k7lxc--- via TowerTalk wrote:
So what other manufacturers of vertical dipoles would be worth doing
business with?
Certainly those that you and N0AX tested 2o years ago. Like any
vertical, their performance will depend on soil conductivity, and they
will work a bit better if roof mounted.
73, Jim K9YC
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