Richard

Obviously, you have the right idea about what I'm trying to do. And I
realize that I'm trying to build something that I am not actually able to
analyze.
I'm top posting because I have nothing valuable to add to the information
you have offered below. But, I do have to admit that I've become such a
poor learner that I havent yet been able to visualize what that antenna
looks like. It sure has the right kind of pattern.
I may be wrong about what kind of pattern is preferable for polar orbiting
satellites. But, it seems that good right hand circular polarization is
desireable toward the horizon, and can be linear when the satellite is at
higher angles.

Jerry






"Richard Clark" wrote in message
...
Let's first consider:
On Sun, 20 Jun 2004 20:01:04 GMT, "Jerry Martes"
wrote:

My principal problem right now is minimizing the nulls in the pattern.
Each null will produce a black line in the picture of te Earth when that
null falls below some threshold.

and then:

On Mon, 21 Jun 2004 05:09:30 GMT, "Jerry Martes"
wrote:
Reg

I see there's something wrong with the way I'm looking at radiators. I
have been thinking that the currents conducted on the outside of the coax
feeding a dipole would noticable effect the dipole's radiation pattern.
I've been thinking that when coax is used to feed a balanced dipole,
half
of the dipole thats connected to the center conductor will see a V shaped
dipole half thats composed oof the other half of the balanced dipole
*and*
the outside of the coax. Maybe this above sentance is not conveying the
message. But, do you see where I'm making my mistake??

Jerry

Hi Jerry,

I presume we are proceeding from your design toward its validation of
characteristics specific to the purpose of monitoring satellite
signals. I further presume chief among these characteristics is near
omnidirectionality with an even gain distribution. Of course these
presumptions may be wrong or incomplete (I may have neglected issues
of circular polarization). Anyway, as an example I have offered:
http://www.qsl.net/kb7qhc/antenna/In...%20F/index.htm

If this example suggests some similar quality, then your design (if it
exhibits less than uniform characteristics) would stand to gain by any
additional sensitivity that comes by way of an excited common mode
which fills a null. Problem is, this means the total absence of
choking, which returns us to the vagaries of luck which will not
always offer such generosity.

Thus the virtue of choking is to guarantee an independence from
caprice doing your designing for you. You are then responsible for
doing it your self at the antenna and the choke makes it independent
of the feed line. The alternative is to find the perfect combination
of line length and antenna (observing only those beneficial
orientations between the two) and imposing that upon your user to meet
the design requirements.

73's
Richard Clark, KB7QHC