Okay, this is off the T-T topic, but since there's enough rattling around,
I'll put in my observations.
The FluidMotion antenna was on display at the Dayton Hamvention last year.
It is a very interesting machine.
Each element consists of a pair of fiberglass tubes, with a box located at
the middle. Inside the box is a side-by-side pair of spools, upon which
are wrapped a copper clad (but I believe the material is actually SS)
perforated foil approximately 3/8" wide, by mebbie 0.080' thick or so, by
pretty-darned-long. The spools are positioned so that the foil strips will
tail out into the fiberglass tubes (one foil to the east, other to the
west). The foil strips are driven out at identical rates by a sheave with
pins, like the advancing mechanism on 35mm film. The sheaves are driven by
a stepper motor. On the bitter end of each strip is a plastic tab, which
keeps the strip from getting hung up inside the fiberglass element tubes.
Each element pair has it's own stepper motor, and at the operating station
is a control box, which controls each of the stepper motors to change
element lengths. Standard configurations are preprogrammed into the box,
and changing tunings is as easy as tweaking any of the elements' lengths
from the control box. There is also a 'hot button' on the panel which will
swap the elements' dimensions to reverse the antenna's heading by 180
degrees... in under a second or three.
|