on 11/14/02 10:51 AM, Jim Shaw at Jim@ShawResources.com wrote:
> QUESTION: Instead of an LPDA, why not use a 3 element SteppIR antenna?
> Don't they cover all frequencies continuously from 13.9 to 30 MHz? Isn't
> that similar to the design goal of an LPDA? Seems like a SteppIR should
> easily cover MARS frequencies in that range. Just asking cause I have no
> first hand experience with either and LPDA or a SteppIR.
The SteppIR antenna has been discussed here ad nauseum. My main issues with
the SteppIR:
1.) Mechanical. How reliable is it? What about condensation inside the
motor, etc. and then what about when all that moisture freezes? It would
just suck the royal you know what to have your antenna freeze up in the
middle of January when chasing that rare DX.
2.) Only 3 elements.
3.) As others have said, the element spacing is only optimized for one band.
4.) It's expensive for just 3 elements.
While the SteppIR I would think certainly have a lot going for it over a 3
element Yagi, I don't think its performance can compare with some of the
bigger multiband Yagis.
It's an interesting antenna and for some people and some installations,
perhaps quite a good one.
73,
Jon
NA9D
-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)
Citizen of the People's Democratic Republik of Illinois
Life Member: ARRL, NRA
Member: AMSAT, DXCC
http://www.qsl.net/na9d
"A life lived in fear is a life half lived."
|