View Single Post
  #6   Report Post  
Old June 10th 04, 07:12 PM
Steve Nosko
 
Posts: n/a
Default


"Yuri Blanarovich" wrote in message
...
Another press write-up:
http://www.planetanalog.com/news/sho...cleID=21402311
Jim, K7JEB


[snip] "A helix
antenna is normally known to be a core radiator, because the current

profile
drops off rapidly; they are just an inductor, and inductance does not like

to
see changes in current, so it's going to buck that.


This sounds like false theory. He is implying that a distributed
inductor opposes a difference in current along its length, no?

The RF current in the distributed inductor can be different along its
length, modeling shows that, but this is AC and it is _always_ opposing the
changing AC (in this case RF) current at any point of the coil. That's what
inductors do. I can't get this to extend to opposing different AC currents
along the length of a long coil. If there is enough field from one end of
the coil coupling to the other end, then a falling field at the first end
tends to oppose a change in the current at that end as well as at the other,
but that's an opposition to a change in instantenous current, which will
increase inductance, not the AC current magnitude...


"What I found was that for any smaller antenna, if you place a
load coil in the middle you can normalize and make the current
through the helix unity; that is, you can maximize it and
linearize it," he added.


I can't get "Linearize" to work. Does he mean, "vary linearly along the
length"? "Normalize" and "unity" are pretty obsure as well.

Guess I'll wait for the movie to comeout.

--
Steve N, K,9;d, c. i My email has no u's.