With a fan dipole, research sponsored by the military showed that it helps
if you can spread the dipoles apart about 8 to 10 inches at the center. I
have a piece of plastic about two feet long and about 8 inches wide that I
drilled holes in for each wire and for a u bolt for the balun. A wire runs
between the holes on each side to connect the dipoles.
Chuck W5PR
On Fri, Sep 29, 2017 at 10:21 PM Jim Brown <jim@audiosystemsgroup.com>
wrote:
> On 9/29/2017 5:35 PM, Don W7WLL wrote:
> > I think I'll leave it in the sorta inv V form for the moment until I
> > decide what I want to do with 160.
>
> In general, inv vee is a compromise configuration that most of us adopt
> because 1) it's easier to rig or 2) we CAN'T rig it flat or 3) can get
> the center a lot higher than we can rig both ends or 4) we want the
> quasi-omni pattern that the inv vee provides (at the expense of strength
> broadside). The simple fact is that the higher a horizontally polarized
> antenna is the better it works.
>
> Horizontally polarized antennas are just STARTING to work at a quarter
> wave height, and a half wave is better. Few of us can rig a horizontally
> polarized antenna for 160M at 1/8 wave (67 ft), and that's miserably
> low. That's why verticals are almost universally used on 160M. Yes, they
> DO need a counterpoise/radial system, and the better that system is, the
> better the antenna works.
>
> At one point I had a 160 dipole at about 120 ft in addition to a Tee
> vertical that was about 80 ft tall with about 30 on-ground radials. I
> did a LOT of A/B comparisons for the first year or two, and the vertical
> nearly always won, often by a lot. The dipole was really weak in the 2-3
> hours before dark -- running legal limit, I could reliably work 800+
> miles, usually first call, with the vertical, but couldn't even get a
> "QRZ?" with the dipole. Eventually the dipole broke and I never bothered
> to replace it.
>
> This slide show is mostly about 160M antennas and radial/counterpoise
> systems, with a lot of attention given to small lots. None of it is
> original -- I'm simply summarizing what I think are the best work by
> others. http://k9yc.com/160MPacificon.pdf
>
> 73, Jim K9YC
>
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