Re: [TowerTalk] Brainstorming: A homebrew Steppir like beam....

[Rob Frohne <frohro@wwc.edu>]

Very interesting idea Rick.

On Apr 25, 2004, at 4:50 PM, Richard (Rick) Karlquist (N6RK) wrote:

> Before the SteppIR came along, I had thought
> about making adjustable height verticals.
> If you only need a 2:1 difference in length, it
> would be quite easy to use a wire element that
> doubles back on itself by wrapping around a moveable pulley,
> where the pulley position is controlled by a nonconductive
> string that goes around a fixed pulley at the end of the
> tube.  This design is homebrewable and completely
> eliminates the BeCu tape issue and the graphite brushes
> and there is no problem with contact resistance, etc.
> You could perhaps use annealed OFHC copper tape to get
> lower element resistance (doesn't need to be stiff).
> With a 2:1 difference in length, you could get 10 thru
> 20 meters, but not 6 meters that way.

Actually, you can probably get 20 through 12 meters assuming you want 
the whole 20 meter band.  (2*14.0 = 28)
> This homebrew technique might be competitive with the
> SteppIR verticals, because you can use tuning
> techniques of the type used with mobile screwdriver antennas.
> (No stepper motor necessary and you don't need to keep track
> of where you are, just tune for a match).
If I was looking for a vertical, I might try this approach.

>  I think when you start to
> get into multiband Yagi's, if your time is worth anything
> at all, the price of the SteppIR Yagi is actually a bargain.
Yes, I suppose that may be true, but my object is not to own a great 
station.  I want to experiment, and I would like to come up with 
something better than what is there now.  If we put our ideas together, 
we may come up with something better than the Steppir in some ways, as 
you may have for the vertical already!

Thanks Rick!

Rob
--
Rob Frohne, Ph.D., P.E.
E.F. Cross School of Engineering
Walla Walla College
http://www.wwc.edu/~frohro/

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