On Mon, 10 Aug 2009 16:23:09 -0700 (PDT), Art Unwin
wrote:

On Aug 10, 5:21*pm, dave wrote:
Art Unwin wrote:
The majority of antennas used today are (commercial) circularly
polarized
Ham antennas remain in the linear domain (ala the Yagi and similar)
There are many reasons espoused in CP advantages in "point to point"
What is the main advantage hams hold over the more popular circular
polarized antennas in its "skip" type useage versus "point to point" ?

Is there a CPOL advantage for atmospherically propagated HF? *I can
think of some disadvantages.

I am all ears. Go for it

Applied CP made simple:

1. Circular polarization is like a drill. Instead of bouncing off
the ionosphere, it drills right through it. Therefore, little or no
skip with CP.

2. Circular polarization is sensitive to the direction of rotation.
If you're sending CP with your right hand, or using a microphone in
your right hand, then you can only hear right hand circular
polarization.

3. CP changes sense every times it bounces off something. Therefore,
you can only hear even numbered bounces with the same sense. Odd
bounces disappear meaning you can hear short skip signals (NVIS), and
long path, but nothing in between.

4. Right hand CP is the most common, because most tuning screws use a
right hand thread. If you want to use left hand CP, you'll need to
find some rather scarce left hand threaded coil forms and tuning
slugs.

I hope this helps.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558