I have a couple of old Hy-Gain antennas with swagged elements. I get these
for free when I take down old towers.
Lets say, for argument, that we have two elements. One slides inside the
other, which is swagged in order to meet the outside diameter of the first one.
These two elements can be tuned to different frequencies by adjusting the
length the first element slides INSIDE the other. To exaggerate, lets say
the first element is 12" inside the swagged element, but the only contact
area between the two elements is the few inches where the second element is
swagged. The rest of the first element is hanging out "in free space" (for
lack of a better term).
Here is the question...will the element INSIDE the other affect the
electrical length of the entire assemble due to the extra metal in "free
space"? Although it is a direct short, will there be any capacitance much
like a gamma match where one material is suspended inside the other?
Dino...k6rix@arrl.net
|