ORIGINAL MESSAGE:
On Fri, 19 Mar 2010 22:22:44 -0600, Larry Benko <xxw0qe@comcast.net>
wrote:
>
>1.) Start with a #10 or #12 self supporting copper wire dipole that is
>about 10" each side of the center (Fres ~ 280MHz)
>2.) I will solder a 2" dia. thin copper disk to each element at the 1/3
>point out from the center on each side and remeasure Fres.
>3.) Then I will move the disks to the 2/3 point from the center and
>remeasure Fres.
>
>Is this reasonable? I will choke the coax, feed it at right angles to
>the dipole and make measurements in my basement with a VNA. Comments
>before I start!
REPLY:
Sounds good, but don't forget to also measure with the disk connected
at its edge as well as its center. The disk adds some capacitance to
the antenna and lowers it's resonant frequency a bit because of that.
73, Bill W6WRT
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