[TowerTalk] Dual Dimensional Slider (DDS) Antenna??

[David Thompson]

An ad on QRZ.com by Mike Lebo is taking a survey about a possible dual
dimension antenna.  The ad shows some configurations for 40 to 10.

Anyone know the skinny on this.  He may be just trying to capitalize on the
questions most of us have on fixed placement booms with adjustable elements
as in the StepIr.   I think it would be a mechanical nightmare to accomplish
this!

Dave K4JRB