Quad and circular polarization
 

Greets OMs,

yesterday i had a QSO with K2US - impressive antenna, by the way i'm using
the station of a local OM near my QTH with a 4 elements 5 band Quad.

The beautiful thing is the 9-9+20 signal around 20.45 UTC, far away in
magnitude from the others stateside signals, around S5-7. So i remember my
father that tell me one day in his opinion the circular polarization in the
better choice... lose no matter about 6 dB, with any kind of polarization
used at the other side except circular - and faraday torsion due to
ionosphere - and in my mind comes 2 questions...

- we take some advantage from the fact that both are using quad antenna ??
- in my non-knowledge of the facts, i have in the past believed that the
quad antenna is near a circular-polarized antenna. Reading books and hearing
some QSO in the air i learn that quad can be horizontal or vertical
polarized, regard the feed point of the quad.. so - the circular
polarization need some kind of "special" feed point or is merely a "circle"
antenna ??

Apologize for the english and for the questions, maybe trivials and stupids,
but i believe one esxperienced OM can say far better than 100 books.

73,
CQ -.-. --.-

Quad and circular polarization
 

"-.-. --.-" ha scritto nel messaggio ...

Yep, and not obviously information, because i'm used to write on the it.*
usenet ierarchy, the contact was made from central Italy :)

-.-. --.-

Quad and circular polarization
 

-.-. --.- wrote:
Greets OMs,

yesterday i had a QSO with K2US - impressive antenna, by the way i'm using
the station of a local OM near my QTH with a 4 elements 5 band Quad.

The beautiful thing is the 9-9+20 signal around 20.45 UTC, far away in
magnitude from the others stateside signals, around S5-7. So i remember my
father that tell me one day in his opinion the circular polarization in the
better choice... lose no matter about 6 dB, with any kind of polarization
used at the other side except circular - and faraday torsion due to
ionosphere - and in my mind comes 2 questions...

- we take some advantage from the fact that both are using quad antenna ??
- in my non-knowledge of the facts, i have in the past believed that the
quad antenna is near a circular-polarized antenna. Reading books and hearing
some QSO in the air i learn that quad can be horizontal or vertical
polarized, regard the feed point of the quad.. so - the circular
polarization need some kind of "special" feed point or is merely a "circle"
antenna ??

Apologize for the english and for the questions, maybe trivials and stupids,
but i believe one esxperienced OM can say far better than 100 books.

73,
CQ -.-. --.-



Circular polarization means you have equal H-Pol and V-Pol radiation,
with one polarization 90 degrees ahead (or behind) of the other.

A quad antenna is a folded dipole.

Quad and circular polarization
 

"-.-. --.-" wrote in message ...
Greets OMs,

yesterday i had a QSO with K2US - impressive antenna, by the way i'm using
the station of a local OM near my QTH with a 4 elements 5 band Quad.

The beautiful thing is the 9-9+20 signal around 20.45 UTC, far away in
magnitude from the others stateside signals, around S5-7. So i remember my
father that tell me one day in his opinion the circular polarization in
the better choice... lose no matter about 6 dB, with any kind of
polarization used at the other side except circular - and faraday torsion
due to ionosphere - and in my mind comes 2 questions...

- we take some advantage from the fact that both are using quad antenna ??
- in my non-knowledge of the facts, i have in the past believed that the
quad antenna is near a circular-polarized antenna. Reading books and
hearing some QSO in the air i learn that quad can be horizontal or
vertical polarized, regard the feed point of the quad.. so - the circular
polarization need some kind of "special" feed point or is merely a
"circle" antenna ??

Apologize for the english and for the questions, maybe trivials and
stupids, but i believe one esxperienced OM can say far better than 100
books.

73,
CQ -.-. --.-


a quad is generally linearly polarized, either vertical or horizontal. to
get circular polarization you need dual driven elements with the proper
phasing.

Quad and circular polarization
 

"Dave" ha scritto nel messaggio
...

a quad is generally linearly polarized, either vertical or horizontal. to
get circular polarization you need dual driven elements with the proper
phasing.

Like a calculated piece of coax used to drive the 2nd element 90 electrical
degrees after the first ??

-.-. --.-

Quad and circular polarization
 

Dave wrote in
:

-.-. --.- wrote:
Greets OMs,

yesterday i had a QSO with K2US - impressive antenna, by the way i'm
using the station of a local OM near my QTH with a 4 elements 5 band
Quad.

The beautiful thing is the 9-9+20 signal around 20.45 UTC, far away
in magnitude from the others stateside signals, around S5-7. So i
remember my father that tell me one day in his opinion the circular
polarization in the better choice... lose no matter about 6 dB, with
any kind of polarization used at the other side except circular - and
faraday torsion due to ionosphere - and in my mind comes 2
questions...

- we take some advantage from the fact that both are using quad
antenna ?? - in my non-knowledge of the facts, i have in the past
believed that the quad antenna is near a circular-polarized antenna.
Reading books and hearing some QSO in the air i learn that quad can
be horizontal or vertical polarized, regard the feed point of the
quad.. so - the circular polarization need some kind of "special"
feed point or is merely a "circle" antenna ??

Apologize for the english and for the questions, maybe trivials and
stupids, but i believe one esxperienced OM can say far better than
100 books.

73,
CQ -.-. --.-



Circular polarization means you have equal H-Pol and V-Pol radiation,
with one polarization 90 degrees ahead (or behind) of the other.

A quad antenna is a folded dipole.

Except the top and bottom arms of a horizontally polarized quad element
are far enough apart to provide some gain and to slightly lower the
pattern from that of a dipole at the quad's central height. In a four or
five element design this can be quite effective. I was on the far end of
the QSO (at VE8ML) back in 1965 when OH8OS tested some very large quads
on 15m. They were impressive.


--
Dave Oldridge+
ICQ 454777283

Quad and circular polarization
 

"-.-. --.-" wrote in message ...

"Dave" ha scritto nel messaggio
...

a quad is generally linearly polarized, either vertical or horizontal.
to get circular polarization you need dual driven elements with the
proper phasing.

Like a calculated piece of coax used to drive the 2nd element 90
electrical degrees after the first ??

-.-. --.-

Hi MG

It isnt at all so simple as feeding one radiator 90 degrees later than
another to get "circular" polarization. For instance two linear radiators
can be fed in phase to get "CP". And two linear radiators can be fed with
one 90 defrees earlier (or later) than the other.
Look at wikipedia http://en.wikipedia.org/wiki/Circular_polarization

I'd expect that you can feed two Quads in phase to get CP along the axis
of their mounting boom. You'd space them appropriately and conect their
fed points appropriately.

Jerry KD6JDJ

Quad and circular polarization
 

"Jerry" wrote in message
...

"-.-. --.-" wrote in message ...

"Dave" ha scritto nel messaggio
...

a quad is generally linearly polarized, either vertical or horizontal.
to get circular polarization you need dual driven elements with the
proper phasing.

Like a calculated piece of coax used to drive the 2nd element 90
electrical degrees after the first ??

-.-. --.-

Hi MG

It isnt at all so simple as feeding one radiator 90 degrees later than
another to get "circular" polarization. For instance two linear
radiators can be fed in phase to get "CP". And two linear radiators can
be fed with one 90 defrees earlier (or later) than the other.
Look at wikipedia http://en.wikipedia.org/wiki/Circular_polarization

I'd expect that you can feed two Quads in phase to get CP along the axis
of their mounting boom. You'd space them appropriately and conect their
fed points appropriately.

Jerry KD6JDJ


Jerry has both bad eyes and bad code. I now see CQ and not MG. Sorry!

Jerry KD6JDJ

Quad and circular polarization
 

Dave wrote:

Circular polarization means you have equal H-Pol and V-Pol radiation,
with one polarization 90 degrees ahead (or behind) of the other.

That's not a very good description, although it's correct. You can
separate a circularly polarized field into vertically and horizontally
polarized components, the sum of which is the circularly polarized
field. And if you do that, you'll find that the two components are 90
degrees out of phase with each other.

But here's a little more complete description: The electric (E) field of
a horizontally polarized wave is horizontal, and the E field of a
vertically polarized wave is vertical. But the E field of a circularly
polarized wave rotates at the transmission frequency, one revolution per
cycle. The instantaneous amplitude of a vertically or horizontally
polarized field is sinusoidal, varying at the transmission frequency.
The amplitude of a circularly polarized wave is constant.

A quad antenna is a folded dipole.

No, it's not.

Roy Lewallen, W7EL

Quad and circular polarization
 

So thanks all for replies. Wikipedia at this page
http://en.wikipedia.org/wiki/Circular_polarization show more, and now i have
also clear in mind the fact that circular polarization is first made by a
physical, circular design of dhe radiant element and i can also have
clockwise or counterclockwise sense of the polarization.

By the way, due to wavelenght we are playing in the HF, i doubt that can be
realized a true circular polarization antenna for HF spectrum. Maybe
something can be realized on VHF and up.
Merely theory dreams in my mind, as in the real life i'm working HF with a
couple of butterfly dipoles covering from 80 to 10 m... :)

Thanks anyway to pay me attention.

73 folks,

-.-. --.-