[TowerTalk] New antenna system
Floyd Sense
fsense at copper.net
Mon Nov 8 18:25:33 EST 2004
Well, as a new SteppIR owner, I can't resist inserting myself into this
"lovefest". While the SteppIR is certainly a good product and their
customer service is indeed first-rate, it seems to me that a cult has
developed around the SteppIR that doesn't tolerate any negative comments or
thoughts. When I obtain a new product, I usually try to learn as much as
possible about how it works and what its limitations are - and there are
always limitations. Reading the comments on this forum would lead one to
believe that there are none with the SteppIR, but that would be incorrect.
When checking out my new 3 element SteppIR, I noticed that the SWR was
higher at one point on one band than elsewhere. So, I used the controller
function to change the length of the driven element to reduce the SWR and
sure enough, that worked just as expected. So then I thought - why not do
the same for the driven element on all the segments of all the "antennas" in
the controller. In doing that, I found that the controller software is not
capable of storing all those changes to just one element per "antenna". If
you are a real modeler/experimenter figuring to play around with different
antenna definitions, how many experimental antennas can you configure and
store? Apparently, not many - a known problem in the software (known to FM,
not to you). Researching this problem led me to another after chatting with
FM support. Oddly enough, the antenna dimensions FOR THE EXACT SAME
FREQUENCY IN THE EXACT SAME BAND are DIFFERENT when you are in "Amateur"
mode vs. "General Freq" mode. What's more, the dimensions for at least one
point on one band are better in the Amateur mode than in the General mode.
So what? Well, if you're using the PC or your rig to control the SteppIR
frequency, you MUST run the controller in General mode.
When I asked a related question on the SteppIR Yahoo forum, one wag
explained to me that a .3 dB difference is insignificant. It certainly is
to me, but I'll bet it isn't to you if you're interested in implementing
your modeling results.
The SteppIR has a few other "warts" that you won't read about, but no need
to go into them here. I'm just amazed that it took this long for someone to
come up with this revolutionary design at an affordable price. But my
amazement doesn't blind me to the shortcomings.
Just to keep to the purpose of this reflector, my new SteppIR sits on top of
a guyed Rohn 25 and all of the new and used pieces/parts of the tower
installation were obtained from folks on this reflector.
K8AC
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