[TowerTalk] Antenna interaction tests

[Jim Lux]

----- Original Message -----
From: "Ian White GM3SEK" <g3sek at ifwtech.co.uk>
To: <towertalk at contesting.com>
Sent: Sunday, May 15, 2005 12:45 AM
Subject: Re: [TowerTalk] Antenna interaction tests


> K4SAV wrote:
> >I am getting ready to mount a 4 element SteppIR at 55 ft, and an XM240
> >on the same mast only 5 feet above the SteppIR. I am concerned about
> >degrading the SteppIR.  I don't think there will be a problem degrading
> >the 40M antenna because I can always retract the SteppIR elements.
> >
> >Can any of you suggest some good tests to perform to see if the SteppIR
> >is being effected?
>
> The whole point of the SteppIR is that you can REtune the element
> lengths to compensate for any detuning, and then store the new values as
> your default settings.
>
> In other words, the best tools for this job are your PC and a modeling
> program such as EZNEC.
>
>
> --
> 73 from Ian GM3SEK

In general, yes, but you could also wind up in a situation where the "extra
stuff" around makes it impossible to get get a good (i.e. low) back or
sidelobe.  The SteppIR is flexible, but you're still limited to the three
elements.

Ian's very right... this is where modeling would be the ticket.  You don't
need a slavish, down to the millimeter, representation of every nut and bolt
for this kind of sensitivity analysis