[TowerTalk] Fw: [SteppIR] 3El height

[Howard Klein]

----Original Message Follows----
From: Jim Lux <jimlux at earthlink.net>

In some cases, one might not even need the phasing network.  You could set
one antenna to present a inductive feedpoint impedance and the other to
have a capacitive reactance, and get your "phase shifter" for free.

Truly, adjustable element lengths in a 2D array (i.e. a stack) gives you a
whole raft of interesting possibilities that are alien to traditional
antenna schemes.
Jim wrote:
*The challenge will be in getting practical experience.  Modeling it is
*simple enough, but with those "extra knobs to twist" it's not clear yet
*what will prove to be the most useful types of pattern.

Jim, W6RMK

That is exactly the problem for an average ham station with average ham 
instruments. In tweaking a four 4 element SteppIR or even more complicated a 
stack of four elements, how can you determine where you are and  which 
dimensions  will give a desired effect? I've modeled a stack of 2 four 
element SteppIR's best I could and then entered those dimensions into YO7 
Optimizer to optimize, for example, gain.  The results for me don't 
necessarily follow my empirical results. It is difficult to know if I have 
improved anything or just screwed it up. No big news but I have definitely 
proven to myself that lowest SWR does not mean best gain. I have found that 
on 20 meters both my four at 45 feet and my four at 85 feet do better than 
both. Seems like a phasing problem but on the other bands results are as 
expected.
Howard..K2HK



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