[TowerTalk] SteppIR compromises redux

Jim Jarvis jimjarvis at verizon.net
Sun Nov 27 12:28:50 EST 2005


Various comments, with respons below:

Sorry but SteppIR is also a compromise antenna!!!
>
> 73 Jim

I know that!
However by reading what many people writes about the SteppIR
it?s easy to get the impression that there is absolutley
no compromise with that antenna.

73 Jim SM2EKM

Sure, but it is not nearly as compromised as most of the others.
>
> 73,   Carl   VE9OV
-0-

Multiband antennas are a compromise.  The 3 el SteppIR will not outperform
a Bencher Skyhawk when you're on its peak.  Or any other 3-monobander
on a single boom design tribander.  Or any optimized monobander on its own
boom, even if those booms were the same length.

The greatest compromise with a tuneable antenna like the steppIR is the
inability to move the element spacing.  You can make up for that, to some
degree, by tuning currents to restore the pattern...but you simply won't
get the peak performance you will with a properly tuned monobander on its
peak.

That said...multibanders on a common boom have their own set of (complex)
compromises...and odds are against even KNOWING where the optimal point is.
(IF f/b, gain & vswr even line up)  As a result, I see the steppIR as a
pretty
decent compromise antenna, with distinct upsides in the 180 degree flip
mode,
and the efficiency of a tuned antenna at all freqs.

But enough of this folly.  We'll just encourage more competition.

If anyone has a 3 el steppIR for sale, I'm shopping for a Spring project.

n2ea
jimjarvis at ieee.org




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