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 -.-. --.-

"-.-. --.-" 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

-.-. --.-

-.-. --.- 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.

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

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

Roy:

[snip]
"Roy Lewallen" wrote in message
treetonline...
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. 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.
[snip]

Hmmmm....

Roy, I don't believe that is a "complete" description of circular
polarization either.

My understanding is that circular polarization is what we call the
polarization of electromagnetic radiation when the electric field vector E
rotates with an angular velocity rather than oscillating back and forth in a
single (linear) direction.

Roy, your description of circular polarization above seems to imply that the
angular velocity of the E vector of a circularly polarized wave is always
"synchronized" with the signal frequency since you stated that it rotates at
one revolution per cycle, or one radian per radian per second.

This of course is the (normal?) situation if the antenna is say a helix
firing along its axis or say crossed dipoles fed with a 90 degree phase
shift, but... to be more complete, we should note that...

Circular polarization does not have to be "synchronous"!

Consider...

What would you call the polarization type of the radiation emitted by the
following radiator?

An ordinary linear dipole fed with RF from a feedline through two slip rings
arranged such that a mechanical drive is able to rotate the dipole at some
arbitrary mechanical angular velocity completely unsynchronized with the RF
carrier.

For example, say it's a 5m dipole driven with 30MHz carrier signal and
mechanically rotated at 1000 revolutions per minute.

Such an arrangement would result in circularly polarized radiation with the
E vector having angular velocity of 1000 revolutions per minute and a
carrier frequency of 30MHz which definitely is not one revolution per cycle.

Thoughts, comments?

--

Pete
Indialantic By-the-Sea, FL

"Peter O. Brackett" wrote in message
m...
Roy:

[snip]
"Roy Lewallen" wrote in message
treetonline...
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. 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.
[snip]

Hmmmm....

Roy, I don't believe that is a "complete" description of circular
polarization either.

My understanding is that circular polarization is what we call the
polarization of electromagnetic radiation when the electric field vector E
rotates with an angular velocity rather than oscillating back and forth in
a single (linear) direction.

Roy, your description of circular polarization above seems to imply that
the angular velocity of the E vector of a circularly polarized wave is
always "synchronized" with the signal frequency since you stated that it
rotates at one revolution per cycle, or one radian per radian per second.

This of course is the (normal?) situation if the antenna is say a helix
firing along its axis or say crossed dipoles fed with a 90 degree phase
shift, but... to be more complete, we should note that...

Circular polarization does not have to be "synchronous"!

Consider...

What would you call the polarization type of the radiation emitted by the
following radiator?

An ordinary linear dipole fed with RF from a feedline through two slip
rings arranged such that a mechanical drive is able to rotate the dipole
at some arbitrary mechanical angular velocity completely unsynchronized
with the RF carrier.

For example, say it's a 5m dipole driven with 30MHz carrier signal and
mechanically rotated at 1000 revolutions per minute.

Such an arrangement would result in circularly polarized radiation with
the E vector having angular velocity of 1000 revolutions per minute and a
carrier frequency of 30MHz which definitely is not one revolution per
cycle.

Thoughts, comments?

--

Pete
Indialantic By-the-Sea, FL

Hi Pete

Your idea of rotating a linearly polarized 30 MHz dipole at 1000 RPM does
not relate to the term "Elyptical Polarization" which is often called
Circular Polarization. The Wikipedia information is fairly complete as it
defines CP..

Jerry KD6JDJ

Peter O. Brackett wrote:

Hmmmm....

Roy, I don't believe that is a "complete" description of circular
polarization either.

My understanding is that circular polarization is what we call the
polarization of electromagnetic radiation when the electric field vector
E rotates with an angular velocity rather than oscillating back and
forth in a single (linear) direction.

Roy, your description of circular polarization above seems to imply that
the angular velocity of the E vector of a circularly polarized wave is
always "synchronized" with the signal frequency since you stated that it
rotates at one revolution per cycle, or one radian per radian per second.

This of course is the (normal?) situation if the antenna is say a helix
firing along its axis or say crossed dipoles fed with a 90 degree phase
shift, but... to be more complete, we should note that...

Circular polarization does not have to be "synchronous"!

Consider...

What would you call the polarization type of the radiation emitted by
the following radiator?

An ordinary linear dipole fed with RF from a feedline through two slip
rings arranged such that a mechanical drive is able to rotate the dipole
at some arbitrary mechanical angular velocity completely unsynchronized
with the RF carrier.

For example, say it's a 5m dipole driven with 30MHz carrier signal and
mechanically rotated at 1000 revolutions per minute.

Such an arrangement would result in circularly polarized radiation with
the E vector having angular velocity of 1000 revolutions per minute and
a carrier frequency of 30MHz which definitely is not one revolution per
cycle.

Thoughts, comments?

That certainly doesn't fit the classical definition of circular
polarization. Circular and linear polarizations are special cases of
elliptical polarization, which all fields actually have, and which is
universally defined in terms of polarization change over each period.
Whatever you want to call the field your mechanical arrangement is
producing, it's not circular polarization in the sense universally used
in the literature.

Roy Lewallen, W7EL

"-.-. --.-" 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.

"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 ??

-.-. --.-