On Sat, Sep 14, 2002 at 09:59:58AM -0400, Guy Olinger, K2AV wrote:
> Without getting into the whys of our fascination with SWR, the StepIR
> answers the concern of all those who cannot stand their SWR to be
> anything other than 1:1, all other concerns notwithstanding.
> Or those who need their antenna to work across an entire octave of HF
> without the element/trap complexity of other solutions.
> Or those who might want to pull in the element length for reasons of
> appearance, wind drag, etc, when not operating.
I believe the length of the fiberglass tubes is constant and the copper
ribbon elements inside the tubes move in and out, so this would not be
> Given that people have tolerated decidedly inferior designs from
> M****** all these years and defended them to the end, I can't see that
> the StepIR particularly deserves any duns, other than the moving parts
> are a complexity that will sooner or later must place it in the
> category of the KT34XA, a favorite, and a performer, that has
> mechanical issues that must be dealt with in the long term.
> As to how long and exactly what issues, the StepIR needs the time in
> grade to see how it does in various environments. Each owner will have
> their own tolerances to whatever develops, and what it takes to keep
> it in repair.
I haven't actually seen it from closer than 100 ft or so (there's one
on K7IM's tower a couple of miles from me), but from the pictures on
the Fluidmotion web site it looks like it should be easily
maintainable, if (or more likely when) required.
> I think that Tom's issues are overstated for the purposes of clarity,
> but in force for theoretical discussions.
> Anyone with YO can run a 3 element problem with the fixed spacings and
> boom length of the StepIR and see that there is a continuous solution
> from 20 to 10, whose accomodation to boom length is no ghastly
> The front-to-back penalty experienced on the StepIR at 10m is less
> than the f/b penalty routinely ignored when stacking two yagis
> designed to be used one at a time in the clear.
> Again, the mechanics will be the achille's heel, if any.
I noticed on the Fluidmotion web site that they offer an extended
73, Bob N7XY
Bob Nielsen, N7XY email@example.com
Bainbridge Island, WA
IOTA NA-065, USI WA-028S