[TowerTalk] Holy SteppIR!

[Jim Lux]

At 08:02 AM 12/27/2005, Michael Tope wrote:

>----- Original Message -----
>From: "Joe Subich" <W4TV at subich.com>
>To: "'Michael Tope'" <W4EF at dellroy.com>; "'StellarCAT'"
><RXDesign at ssvecnet.com>; "'tower'" <towertalk at contesting.com>
>Sent: Tuesday, December 27, 2005 7:26 AM
>Subject: RE: [TowerTalk] Holy SteppIR!
>
>
> >
> > Mike,
> >
> >> The antenna array in question (6 yagi H-frame), has enough
> >> gain and is mounted high enough that it is probably starting to
> >> look more like a high-gain VHF/UHF array than a traditional
> >> stack of HF yagis.
> >
> > The lobe/null structure of this array is such that the elevation
> > would need to be well above 20 degrees before the ground reflection
> > disappeared.
> >
>
>Yeah, that sounds about right. Below that level, the vertical pattern
>nulls shouldn't be affected too much (if at all) by the "tilt".


Assuming you didn't phase the elements to create a null at the 
ground..?  With a SteppIR, there's no requirement that the antennas in the 
stack will be radiating at the same phase.  You can arbitrarily adjust the 
phases, so you can put a null wherever you want. In fact, it's easier to 
place nulls than to place lobes.