Topband: New 3 el 160m yagi at 7J4AAL

[Tom W8JI]

> On Tue,8/19/2014 10:03 AM, Doug Renwick wrote:
>> I thought the consensus now is yagi antennas on 160 don't perform well 
>> (i.e. OH8X) when compared to vertical arrays.
>
> That is STRONGLY dependent on the height of the Yagi and soil conductivity 
> around the vertical antenna.  A horizontal antenna lower than about a half 
> wave is a "low" antenna, so the vertical pattern is compromised. On the 
> other hand, verticals are strongly affected by soil conductivity -- as 
> much as 6 dB between very poor and very good -- while horizontal antennas 
> are not.  This Yagi is at almost 3/8 wavelength on 160, pretty good, but 
> still not great. I'd guess the gain to be no better than 5 dB over a 
> dipole at the same height.

It also depends on the earth's magnetic field and how it affects the 
ionosphere, apparently.

>From my location, at one point in time, I had phased full-size wire dipoles 
(droopy Inverted Vee dipoles) at about 300 feet apex height, with the leg 
ends at least around 250 feet. It was averaged over thousands of reports a 
little less than the optimized phase and current (NOT a hybrid) four square 
I have. It never was significantly stronger.

But that is just here at this location.

When I was young and in Ohio I had a dipole on an FM tower at 330 feet over 
a black sandy loam soil marsh. I remembered how well it worked. That was why 
I installed a 300 ft tower here. Once I installed the 300 ft tower, which 
was on an insulator, my memory cleared and I got real. I remembered the few 
times I A-B tested a 130 ft vertical at my house a few miles away and 
couldn't see much actual difference.

80 meters is a different story with horizontal polarization.

It's like those fast muscle cars we all had in the 1960's that we remember 
as being fast and wonderful, but were actually slower, handled much worse, 
were far less comfortable and reliable, and had terrible fuel mileage than 
our modern showroom cars.