Incoming radio wave polarisation
 

I have on order a tilting system for my antenna to probe the
polarisation of incoming signals
for maximum audio clarity and gain.
There are instruments out there that can automatically tell you the
polarisation
without one taking the trouble to pan the antenna in different
directions.
Anybody out there follow such a procedure with the antenna or use a
homebrew
or commercial instrument to save time?
Regards
Art

Incoming radio wave polarisation
 

In article ,
"AI4QJ" wrote:

"Art Unwin" wrote in message
...
I have on order a tilting system for my antenna to probe the
polarisation of incoming signals
for maximum audio clarity and gain.
There are instruments out there that can automatically tell you the
polarisation
without one taking the trouble to pan the antenna in different
directions.
Anybody out there follow such a procedure with the antenna or use a
homebrew
or commercial instrument to save time?
Regards
Art

How do you change the polarity of a helical antenna?

You wind the Helix in the OPPOSITE Direction....... Duh.....

Incoming radio wave polarisation
 

On Sat, 15 Mar 2008 08:52:01 -0700 (PDT), Art Unwin
wrote:

Anybody out there follow such a procedure with the antenna

Phase steerable array.

73's
Richard Clark, KB7QHC

Incoming radio wave polarisation
 

On Sat, 15 Mar 2008 14:32:57 -0400, "AI4QJ" wrote:

How do you change the polarity of a helical antenna?

Swap the feeds.

73's
Richard Clark, KB7QHC

Incoming radio wave polarisation
 

"AI4QJ" wrote in
:


"Richard Clark" wrote in message
...
On Sat, 15 Mar 2008 14:32:57 -0400, "AI4QJ" wrote:

How do you change the polarity of a helical antenna?

Swap the feeds.

Ha ha Richard, I assume you are aware that this is a joke given that a
helical antenna is circularly polarized. I am not so sure about this

AI4QJ, perhaps you have a different understanding of the meaning of
circular polarisation to most of us.

Owen

Incoming radio wave polarisation
 

Art Unwin wrote:
I have on order a tilting system for my antenna to probe the
polarisation of incoming signals
for maximum audio clarity and gain.
There are instruments out there that can automatically tell you the
polarisation
without one taking the trouble to pan the antenna in different
directions.

Never saw one that didn't need an antenna capable of being switched
(either electronically or machanically) beween different polarizations.
Which instrument did you see?

Alan

Incoming radio wave polarisation
 

"AI4QJ" wrote in
:

....
Are you talking about the possibility of Art communicating with other
people who are transmitting on similar helical circularly polarized
antennas where CW vs CCW direction must be considered? I dismissed

If this is his compact wonder, it is probably not an axial mode helical.
(I don't know that one could ever describe an axial mode helical as
'compact'.)

Normal mode helicals deliver linear polarisation.

this possibility entirely. Most hams's signals arrive either veritcal,
norizontal or somewhere in between (not rotating) originating at a
linear polarized source. Is he communicating with satellites? I really
haven't heard of helix antennas on the HF bands other than the Unwin
compact model. If so, then yes, you can only switch the feedpoint to

Normal mode helicals are commonly used on HF.

change from CW to CCW and that can make a BIG difference in gain. The
probability of Art finding another HF helical to QSO with should be
negligible to null. Satellites are another matter.

Owen

Incoming radio wave polarisation
 

On Mar 16, 12:55 am, Owen Duffy wrote:
"AI4QJ" wrote :

...

Are you talking about the possibility of Art communicating with other
people who are transmitting on similar helical circularly polarized
antennas where CW vs CCW direction must be considered? I dismissed

If this is his compact wonder, it is probably not an axial mode helical.
(I don't know that one could ever describe an axial mode helical as
'compact'.)

Normal mode helicals deliver linear polarisation.

this possibility entirely. Most hams's signals arrive either veritcal,
norizontal or somewhere in between (not rotating) originating at a
linear polarized source. Is he communicating with satellites? I really
haven't heard of helix antennas on the HF bands other than the Unwin
compact model. If so, then yes, you can only switch the feedpoint to

Normal mode helicals are commonly used on HF.

change from CW to CCW and that can make a BIG difference in gain. The
probability of Art finding another HF helical to QSO with should be
negligible to null. Satellites are another matter.

Owen

See recent posting on E ham
Art

Incoming radio wave polarisation
 

In article ,
You wrote:

In article ,
"AI4QJ" wrote:

"Art Unwin" wrote in message
...
I have on order a tilting system for my antenna to probe the
polarisation of incoming signals
for maximum audio clarity and gain.
There are instruments out there that can automatically tell you the
polarisation
without one taking the trouble to pan the antenna in different
directions.
Anybody out there follow such a procedure with the antenna or use a
homebrew
or commercial instrument to save time?
Regards
Art

How do you change the polarity of a helical antenna?

You wind the Helix in the OPPOSITE Direction....... Duh.....

Just for "Grins" consider this..... What Polorization would you get
if you mounted the Dipole Feed of a Corner Reflector Antenna, at
45° instead of inline with the Axis of the Reflector?

Incoming radio wave polarisation
 

Art wrote:
"Normal mode helicals are commonly used on HF."

Yes. Such antennas include small diameter coils making up solenoids. The
turns act as small stacked loops.

A small loop acts as a short dipole but with its E and H fields
interchanged. See page 58 of the 3rd edition of "Antennas" by Kraus,
Marthefka, et al.

Best regards, Richard Harrison, KB5WZI