[TowerTalk] 43' vertical mod for true resonance on 80M

[Michael Tope]

Dave Tipton wrote:

>Has anyone ever taken one of these 43 foot verticals and done something
>similar to the 38 Foot 80M Capacitively loaded wire vertical?  Obviously
>since you have the extra 5 feet, you wouldn't need as large of a capacity
>hat, but it would have the added benefit of being resonant on 80M and
>providing you with 2 guy wires at the top...  You could probably almost
>justify the cost of the thing just in that you'd get a killer antenna on
>75/80 with just a very minor modification.  (Adding a wire capacity hat
>sloping downward.)
>
>http://home.comcast.net/~kb0fhp/80M_Vertical/80M_Vertical.htm is the link to
>the design I am talking about.
>
>  
>
I used a 45' vertical in the field with 4 sloping top-hat wires. On 160 
meters it was centered loaded with an air wound inductor. Radiation 
resistance was about 6 ohms. I  had lots of radials so it worked pretty 
well (30 radials at 100' each). Since I had no way to bypass the center 
loading coil when QSYing from 160 to 80 meters, I mounted a short cross 
arm on top of the 45' vertical and then I just hoisted a 66' wire in 
parallel to the 45ft radiator (I pulled the 21ft of extra wire [i.e. 
66'-45'] over sideways to form an inverted-L). This arrangement felt 
very competitive on 80 meters when I used it in the 2005 CQ WW CW 
contest from the El Mirage dry lake bed just north of Los Angeles, Ca.

I think W7LR used do very well with a single 90' top-load vertical on 
160 meters (equivalent to 45' on 80 meters). Now I think he has some 
kind of phased array, but the elements in the array may be the same (90' 
of aluminum irrigation tubing)

73, Mike W4EF/6..............................