Re: Topband: circular polarization on 160m
hi Guys, interesting discussion If want, hear this file, https://drive.google.com/file/d/0B8I6Nck0GwTdYTI0MzVkY2QtYjUyYS00YmE3LTk4NTktNWVlNzE2ZGFiYmE1/edit?usp=sharing this is E74AW and OZ1LXJ recording of ZL3IX, at same time, John was so kind and sinchronise those two audio recordings together in one file, will hear how QSB is different on different station, when peak is on my side, deep gos to John and VV thanks, 73 cul dado E74AW Дана 06.02.2014 06:21, James Wolf је написао: Jose, I am only presenting the possibility that if the ionosphere (where 160 propagation happens) isn't uniformly smooth and instead consists of warps, wrinkles and tilts that in a *dynamic ionosphere*, this could be at least one reason we are experiencing slow fades. Elliptical polarization, assuming that it is ever changing, could provide yet another degree of selective fading. I'm don't think I *totally* understand why KL7AJ says that at HF the ionosphere forbids the propagation of linearly polarized signals. If at the magnetic equator, and signals were East to West to equal the earth magnetic tilt of the signals, it seems that at an instance in time that a linear polarized signal could happen. But that may be nit picking. Jim - KR9U From: JC N4IS [mailto:n...@comcast.net] Sent: Wednesday, February 05, 2014 10:45 PM To: jbw...@comcast.net; 'Tom W8JI'; he...@vitelcom.net; topband@contesting.com Subject: RE: Topband: circular polarization on 160m James You brought a good article about HF propagation, however the behavor on 160m is different from HF. If you check on the KL7A arcticle figure 1 what is happening between 1 and 2 MHz you can see that the green and red does not behaivor the same way as above 2 MHz. This subject is more complex because there us no shirt answer, actualy between 1 and 2 MHz. the ionosphere does not support linear polariration wave. The wave are actualy eliptical and not circular for most directions. You can check the long answer on the must read book from NM7M . R Brown 'The Big Gun's Guied to Low Band Propagation . Magneto-iomic Theory pag 47 to 56 ; and Power coupling pag 57. Thanks to Karl. K9LA, the book is available on his also must read site on the 160m link http://k9la.us/html/160m.html [1] Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband [2] Links: -- [1] http://k9la.us/html/160m.html [2] http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Here are some pictures and a sound file or two... http://www.w8ji.com/HF%20circular%20polarization.htm - Original Message - From: d...@prijedor.com To: topband@contesting.com Sent: Wednesday, February 12, 2014 6:41 AM Subject: Re: Topband: circular polarization on 160m hi Guys, interesting discussion If want, hear this file, https://drive.google.com/file/d/0B8I6Nck0GwTdYTI0MzVkY2QtYjUyYS00YmE3LTk4NTktNWVlNzE2ZGFiYmE1/edit?usp=sharing this is E74AW and OZ1LXJ recording of ZL3IX, at same time, John was so kind and sinchronise those two audio recordings together in one file, will hear how QSB is different on different station, when peak is on my side, deep gos to John and VV thanks, 73 cul dado E74AW Дана 06.02.2014 06:21, James Wolf је написао: Jose, I am only presenting the possibility that if the ionosphere (where 160 propagation happens) isn't uniformly smooth and instead consists of warps, wrinkles and tilts that in a *dynamic ionosphere*, this could be at least one reason we are experiencing slow fades. Elliptical polarization, assuming that it is ever changing, could provide yet another degree of selective fading. I'm don't think I *totally* understand why KL7AJ says that at HF the ionosphere forbids the propagation of linearly polarized signals. If at the magnetic equator, and signals were East to West to equal the earth magnetic tilt of the signals, it seems that at an instance in time that a linear polarized signal could happen. But that may be nit picking. Jim - KR9U From: JC N4IS [mailto:n...@comcast.net] Sent: Wednesday, February 05, 2014 10:45 PM To: jbw...@comcast.net; 'Tom W8JI'; he...@vitelcom.net; topband@contesting.com Subject: RE: Topband: circular polarization on 160m James You brought a good article about HF propagation, however the behavor on 160m is different from HF. If you check on the KL7A arcticle figure 1 what is happening between 1 and 2 MHz you can see that the green and red does not behaivor the same way as above 2 MHz. This subject is more complex because there us no shirt answer, actualy between 1 and 2 MHz. the ionosphere does not support linear polariration wave. The wave are actualy eliptical and not circular for most directions. You can check the long answer on the must read book from NM7M . R Brown 'The Big Gun's Guied to Low Band Propagation . Magneto-iomic Theory pag 47 to 56 ; and Power coupling pag 57. Thanks to Karl. K9LA, the book is available on his also must read site on the 160m link http://k9la.us/html/160m.html [1] Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband [2] Links: -- [1] http://k9la.us/html/160m.html [2] http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4259 / Virus Database: 3697/7085 - Release Date: 02/11/14 _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Hello all, My original post regarding circular polarization receiving antennas for 160 was posted 2/2/2014 as a comment on Bill, VE3CSK's post regarding his observation of apparent rapid polarization shifts in the signal received from FT5ZM, on Amsteram Island at their sunrise. Bill was using his K3 in diversity mode to observe the apparent rapid polarization shifts by using both vertical and horizontal receive antennas. The rapid apparent polarization shifts seemed quite different from the slower QSB that we often experience on 160. I post my original hurried off-hand comment and Bill's post below; I wonder what circular-polarized RX antennas might have to offer on 160? Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill and Liz Sent: Sunday, February 02, 2014 8:37 PM To: topband@contesting.com Subject: Topband: FT5ZM SIGNAL I have been listening several evenings now on 160M using my K3 in diversity mode with the TX vertical array on one receiver and a full-wave horizontal loop on the other. I have been struck by the often rapid change in the signal as received on one antenna or the other. As sunrise on Amsterdam approaches this shift becomes quite rapid, with the recovered signal bouncing back and forth ear to ear. Early on, before I began listening in diversity mode, I thought it was rapid QSB taking the signal down into the noise but now realize that it is the angle of the arriving signal which is rapidly changing over the path. No wonder some of the guys have been having problems copying/working the expedition on topband! Bill VE3CSK This seemed to provoke an interesting, lively and informative discussion by a number of people who have explored 160m ionosphere propagation in far greater depth than I have. Some of the commentary piqued my interest and caused me to want to do some more research! Thanks guys, and thanks, Tom, for your recent postings of your recordings from KH6AT etc.! Rather informative and thought-provoking! I must confess that all of my experience with circular polarization has been at UHF (400 MHz range) for spacecraft telemetry and 1.4 GHz for GPS signals. In these cases circular polarization is employed to contend with the Faraday Rotation of signals as they propagate through Earth's atmosphere. These signals generally originate beyond the ionosphere except for a few birds that might pass through the magneto-tail on the lee-side (dark-side) of earth away from the solar wind. Very different from 160m signals that originate on Earth's surface and are reflected from an ionization layer in the ionosphere! Bill's observations are really interesting and seem to suggest something other than the usual slow fades that we are used to on topband. Surely piqued my curiosity! I would think that with proper phase control one could construct circular polarized 160m receive antennas that could be less than full-size if preamps were employed. It's interesting to consider that such an antenna would probably be RHCP in one direction and LHCP in the opposite direction! If I wasn't so disabled at present, I' be tempted to build something to experiment with, just because I miss building experimenting with and measuring antennas! Very enjoyable activities for me! Anyway, thanks all for all the commentary and insightful and thought-provoking discussions! Bill's observations seem to suggest something different at work that may deserve some further investigation and exploration! That led me to wondering about circular polarization, or perhaps some rapid high-speed commutation between horizontally polarized and vertically polarized receive antennas. Thanks! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Wednesday, February 12, 2014 10:41 AM To: d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m Here are some pictures and a sound file or two... http://www.w8ji.com/HF%20circular%20polarization.htm - Original Message - From: d...@prijedor.com To: topband@contesting.com Sent: Wednesday, February 12, 2014 6:41 AM Subject: Re: Topband: circular polarization on 160m hi Guys, interesting discussion If want, hear this file, https://drive.google.com/file/d/0B8I6Nck0GwTdYTI0MzVkY2QtYjUyYS00YmE3LTk4NTktNWVlNzE2ZGFiYmE1/edit?usp=sharing this is E74AW and OZ1LXJ recording of ZL3IX, at same time, John was so kind and sinchronise those two audio recordings together in one file, will hear how QSB is different on different station, when peak is on my side, deep gos to John and VV thanks, 73 cul dado E74AW Дана 06.02.2014 06:21, James Wolf је написао: Jose, I am only presenting the possibility that if the ionosphere (where 160 propagation happens) isn't uniformly smooth and instead consists of warps, wrinkles and tilts
Re: Topband: circular polarization on 160m -BTW
BTW - does anyone know if the EME boys employ circular polarization? 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Wednesday, February 12, 2014 1:35 PM To: 'Tom W8JI'; d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m Hello all, My original post regarding circular polarization receiving antennas for 160 was posted 2/2/2014 as a comment on Bill, VE3CSK's post regarding his observation of apparent rapid polarization shifts in the signal received from FT5ZM, on Amsteram Island at their sunrise. Bill was using his K3 in diversity mode to observe the apparent rapid polarization shifts by using both vertical and horizontal receive antennas. The rapid apparent polarization shifts seemed quite different from the slower QSB that we often experience on 160. I post my original hurried off-hand comment and Bill's post below; I wonder what circular-polarized RX antennas might have to offer on 160? Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill and Liz Sent: Sunday, February 02, 2014 8:37 PM To: topband@contesting.com Subject: Topband: FT5ZM SIGNAL I have been listening several evenings now on 160M using my K3 in diversity mode with the TX vertical array on one receiver and a full-wave horizontal loop on the other. I have been struck by the often rapid change in the signal as received on one antenna or the other. As sunrise on Amsterdam approaches this shift becomes quite rapid, with the recovered signal bouncing back and forth ear to ear. Early on, before I began listening in diversity mode, I thought it was rapid QSB taking the signal down into the noise but now realize that it is the angle of the arriving signal which is rapidly changing over the path. No wonder some of the guys have been having problems copying/working the expedition on topband! Bill VE3CSK This seemed to provoke an interesting, lively and informative discussion by a number of people who have explored 160m ionosphere propagation in far greater depth than I have. Some of the commentary piqued my interest and caused me to want to do some more research! Thanks guys, and thanks, Tom, for your recent postings of your recordings from KH6AT etc.! Rather informative and thought-provoking! I must confess that all of my experience with circular polarization has been at UHF (400 MHz range) for spacecraft telemetry and 1.4 GHz for GPS signals. In these cases circular polarization is employed to contend with the Faraday Rotation of signals as they propagate through Earth's atmosphere. These signals generally originate beyond the ionosphere except for a few birds that might pass through the magneto-tail on the lee-side (dark-side) of earth away from the solar wind. Very different from 160m signals that originate on Earth's surface and are reflected from an ionization layer in the ionosphere! Bill's observations are really interesting and seem to suggest something other than the usual slow fades that we are used to on topband. Surely piqued my curiosity! I would think that with proper phase control one could construct circular polarized 160m receive antennas that could be less than full-size if preamps were employed. It's interesting to consider that such an antenna would probably be RHCP in one direction and LHCP in the opposite direction! If I wasn't so disabled at present, I' be tempted to build something to experiment with, just because I miss building experimenting with and measuring antennas! Very enjoyable activities for me! Anyway, thanks all for all the commentary and insightful and thought-provoking discussions! Bill's observations seem to suggest something different at work that may deserve some further investigation and exploration! That led me to wondering about circular polarization, or perhaps some rapid high-speed commutation between horizontally polarized and vertically polarized receive antennas. Thanks! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Wednesday, February 12, 2014 10:41 AM To: d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m Here are some pictures and a sound file or two... http://www.w8ji.com/HF%20circular%20polarization.htm - Original Message - From: d...@prijedor.com To: topband@contesting.com Sent: Wednesday, February 12, 2014 6:41 AM Subject: Re: Topband: circular polarization on 160m hi Guys, interesting discussion If want, hear this file, https://drive.google.com/file/d/0B8I6Nck0GwTdYTI0MzVkY2QtYjUyYS00YmE3LTk4NTktNWVlNzE2ZGFiYmE1/edit?usp=sharing this is E74AW and OZ1LXJ recording of ZL3IX, at same time, John was so kind and sinchronise those two audio recordings together in one file, will hear how QSB
Re: Topband: circular polarization on 160m -BTW
Here’s a recent link from Ed KL7UW regarding his experience with Adaptive Polarity Reception: http://www.kl7uw.com/LINRAD.htm We were discussing the K3 and dual receiver diversity mode, and I had asked him about his EME and polarity antennas. 160M did come into the conversation as well. Might not be an end all answer but it’s a start. 73, Gary NL7Y BTW - does anyone know if the EME boys employ circular polarization? 73, Charlie, K4OTV _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m -BTW-WOW!
Wow! That's really interesting, with really detailed information and directions, Gary!! Thanks for sharing!! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary and Kathleen Pearse Sent: Wednesday, February 12, 2014 1:54 PM To: topband List Subject: Re: Topband: circular polarization on 160m -BTW Here's a recent link from Ed KL7UW regarding his experience with Adaptive Polarity Reception: http://www.kl7uw.com/LINRAD.htm We were discussing the K3 and dual receiver diversity mode, and I had asked him about his EME and polarity antennas. 160M did come into the conversation as well. Might not be an end all answer but it's a start. 73, Gary NL7Y BTW - does anyone know if the EME boys employ circular polarization? 73, Charlie, K4OTV _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m -BTW
Thanks, Joel! That makes perfect sense to me! I don’t keep up with EME, as I’m an HF CW DXer, but it seemed that the EME guys might use circular polarization to contend with the Faraday Rotation in Earth’s atmosphere, from my spacecraft days of long ago! Thanks! 73, Charlie, K4OTV From: Joel Harrison [mailto:w...@w5zn.org] Sent: Wednesday, February 12, 2014 2:14 PM To: Charlie Cunningham Cc: Tom W8JI; d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m -BTW Yes, on some of the bands circular polarization is used for EME On Wed, Feb 12, 2014 at 12:47 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: BTW - does anyone know if the EME boys employ circular polarization? 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Wednesday, February 12, 2014 1:35 PM To: 'Tom W8JI'; d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m Hello all, My original post regarding circular polarization receiving antennas for 160 was posted 2/2/2014 as a comment on Bill, VE3CSK's post regarding his observation of apparent rapid polarization shifts in the signal received from FT5ZM, on Amsteram Island at their sunrise. Bill was using his K3 in diversity mode to observe the apparent rapid polarization shifts by using both vertical and horizontal receive antennas. The rapid apparent polarization shifts seemed quite different from the slower QSB that we often experience on 160. I post my original hurried off-hand comment and Bill's post below; I wonder what circular-polarized RX antennas might have to offer on 160? Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill and Liz Sent: Sunday, February 02, 2014 8:37 PM To: topband@contesting.com Subject: Topband: FT5ZM SIGNAL I have been listening several evenings now on 160M using my K3 in diversity mode with the TX vertical array on one receiver and a full-wave horizontal loop on the other. I have been struck by the often rapid change in the signal as received on one antenna or the other. As sunrise on Amsterdam approaches this shift becomes quite rapid, with the recovered signal bouncing back and forth ear to ear. Early on, before I began listening in diversity mode, I thought it was rapid QSB taking the signal down into the noise but now realize that it is the angle of the arriving signal which is rapidly changing over the path. No wonder some of the guys have been having problems copying/working the expedition on topband! Bill VE3CSK This seemed to provoke an interesting, lively and informative discussion by a number of people who have explored 160m ionosphere propagation in far greater depth than I have. Some of the commentary piqued my interest and caused me to want to do some more research! Thanks guys, and thanks, Tom, for your recent postings of your recordings from KH6AT etc.! Rather informative and thought-provoking! I must confess that all of my experience with circular polarization has been at UHF (400 MHz range) for spacecraft telemetry and 1.4 GHz for GPS signals. In these cases circular polarization is employed to contend with the Faraday Rotation of signals as they propagate through Earth's atmosphere. These signals generally originate beyond the ionosphere except for a few birds that might pass through the magneto-tail on the lee-side (dark-side) of earth away from the solar wind. Very different from 160m signals that originate on Earth's surface and are reflected from an ionization layer in the ionosphere! Bill's observations are really interesting and seem to suggest something other than the usual slow fades that we are used to on topband. Surely piqued my curiosity! I would think that with proper phase control one could construct circular polarized 160m receive antennas that could be less than full-size if preamps were employed. It's interesting to consider that such an antenna would probably be RHCP in one direction and LHCP in the opposite direction! If I wasn't so disabled at present, I' be tempted to build something to experiment with, just because I miss building experimenting with and measuring antennas! Very enjoyable activities for me! Anyway, thanks all for all the commentary and insightful and thought-provoking discussions! Bill's observations seem to suggest something different at work that may deserve some further investigation and exploration! That led me to wondering about circular polarization, or perhaps some rapid high-speed commutation between horizontally polarized and vertically polarized receive antennas. Thanks! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Wednesday, February 12, 2014 10:41 AM To: d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular
Re: Topband: circular polarization on 160m -BTW
... circular polarization is standard on 23cm, 13cm and 9cm EME. For 10 GHz it is becoming more popular (because there are now feed designs that can be (more) easily reproduced on this band. 73ss Carsten, DL6LAU (QRV on 23cm, 13cm, 10GHz and 24GHz EME @ DL0SHF) Am 12.02.14 19:47, schrieb Charlie Cunningham: BTW - does anyone know if the EME boys employ circular polarization? 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Wednesday, February 12, 2014 1:35 PM To: 'Tom W8JI'; d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m Hello all, My original post regarding circular polarization receiving antennas for 160 was posted 2/2/2014 as a comment on Bill, VE3CSK's post regarding his observation of apparent rapid polarization shifts in the signal received from FT5ZM, on Amsteram Island at their sunrise. Bill was using his K3 in diversity mode to observe the apparent rapid polarization shifts by using both vertical and horizontal receive antennas. The rapid apparent polarization shifts seemed quite different from the slower QSB that we often experience on 160. I post my original hurried off-hand comment and Bill's post below; I wonder what circular-polarized RX antennas might have to offer on 160? Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill and Liz Sent: Sunday, February 02, 2014 8:37 PM To: topband@contesting.com Subject: Topband: FT5ZM SIGNAL I have been listening several evenings now on 160M using my K3 in diversity mode with the TX vertical array on one receiver and a full-wave horizontal loop on the other. I have been struck by the often rapid change in the signal as received on one antenna or the other. As sunrise on Amsterdam approaches this shift becomes quite rapid, with the recovered signal bouncing back and forth ear to ear. Early on, before I began listening in diversity mode, I thought it was rapid QSB taking the signal down into the noise but now realize that it is the angle of the arriving signal which is rapidly changing over the path. No wonder some of the guys have been having problems copying/working the expedition on topband! Bill VE3CSK This seemed to provoke an interesting, lively and informative discussion by a number of people who have explored 160m ionosphere propagation in far greater depth than I have. Some of the commentary piqued my interest and caused me to want to do some more research! Thanks guys, and thanks, Tom, for your recent postings of your recordings from KH6AT etc.! Rather informative and thought-provoking! I must confess that all of my experience with circular polarization has been at UHF (400 MHz range) for spacecraft telemetry and 1.4 GHz for GPS signals. In these cases circular polarization is employed to contend with the Faraday Rotation of signals as they propagate through Earth's atmosphere. These signals generally originate beyond the ionosphere except for a few birds that might pass through the magneto-tail on the lee-side (dark-side) of earth away from the solar wind. Very different from 160m signals that originate on Earth's surface and are reflected from an ionization layer in the ionosphere! Bill's observations are really interesting and seem to suggest something other than the usual slow fades that we are used to on topband. Surely piqued my curiosity! I would think that with proper phase control one could construct circular polarized 160m receive antennas that could be less than full-size if preamps were employed. It's interesting to consider that such an antenna would probably be RHCP in one direction and LHCP in the opposite direction! If I wasn't so disabled at present, I' be tempted to build something to experiment with, just because I miss building experimenting with and measuring antennas! Very enjoyable activities for me! Anyway, thanks all for all the commentary and insightful and thought-provoking discussions! Bill's observations seem to suggest something different at work that may deserve some further investigation and exploration! That led me to wondering about circular polarization, or perhaps some rapid high-speed commutation between horizontally polarized and vertically polarized receive antennas. Thanks! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Wednesday, February 12, 2014 10:41 AM To: d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m Here are some pictures and a sound file or two... http://www.w8ji.com/HF%20circular%20polarization.htm - Original Message - From: d...@prijedor.com To: topband@contesting.com Sent: Wednesday, February 12, 2014 6:41 AM Subject: Re: Topband: circular polarization on 160m hi Guys, interesting
Re: Topband: circular polarization on 160m -BTW
Thanks for the info Carsten! Makes perfect sense to me, based on my spacecraft experience of long ago. Thanks for the update from the EME crowd! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carsten Esch Sent: Wednesday, February 12, 2014 2:24 PM To: topband@contesting.com Subject: Re: Topband: circular polarization on 160m -BTW ... circular polarization is standard on 23cm, 13cm and 9cm EME. For 10 GHz it is becoming more popular (because there are now feed designs that can be (more) easily reproduced on this band. 73ss Carsten, DL6LAU (QRV on 23cm, 13cm, 10GHz and 24GHz EME @ DL0SHF) Am 12.02.14 19:47, schrieb Charlie Cunningham: BTW - does anyone know if the EME boys employ circular polarization? 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Wednesday, February 12, 2014 1:35 PM To: 'Tom W8JI'; d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m Hello all, My original post regarding circular polarization receiving antennas for 160 was posted 2/2/2014 as a comment on Bill, VE3CSK's post regarding his observation of apparent rapid polarization shifts in the signal received from FT5ZM, on Amsteram Island at their sunrise. Bill was using his K3 in diversity mode to observe the apparent rapid polarization shifts by using both vertical and horizontal receive antennas. The rapid apparent polarization shifts seemed quite different from the slower QSB that we often experience on 160. I post my original hurried off-hand comment and Bill's post below; I wonder what circular-polarized RX antennas might have to offer on 160? Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill and Liz Sent: Sunday, February 02, 2014 8:37 PM To: topband@contesting.com Subject: Topband: FT5ZM SIGNAL I have been listening several evenings now on 160M using my K3 in diversity mode with the TX vertical array on one receiver and a full-wave horizontal loop on the other. I have been struck by the often rapid change in the signal as received on one antenna or the other. As sunrise on Amsterdam approaches this shift becomes quite rapid, with the recovered signal bouncing back and forth ear to ear. Early on, before I began listening in diversity mode, I thought it was rapid QSB taking the signal down into the noise but now realize that it is the angle of the arriving signal which is rapidly changing over the path. No wonder some of the guys have been having problems copying/working the expedition on topband! Bill VE3CSK This seemed to provoke an interesting, lively and informative discussion by a number of people who have explored 160m ionosphere propagation in far greater depth than I have. Some of the commentary piqued my interest and caused me to want to do some more research! Thanks guys, and thanks, Tom, for your recent postings of your recordings from KH6AT etc.! Rather informative and thought-provoking! I must confess that all of my experience with circular polarization has been at UHF (400 MHz range) for spacecraft telemetry and 1.4 GHz for GPS signals. In these cases circular polarization is employed to contend with the Faraday Rotation of signals as they propagate through Earth's atmosphere. These signals generally originate beyond the ionosphere except for a few birds that might pass through the magneto-tail on the lee-side (dark-side) of earth away from the solar wind. Very different from 160m signals that originate on Earth's surface and are reflected from an ionization layer in the ionosphere! Bill's observations are really interesting and seem to suggest something other than the usual slow fades that we are used to on topband. Surely piqued my curiosity! I would think that with proper phase control one could construct circular polarized 160m receive antennas that could be less than full-size if preamps were employed. It's interesting to consider that such an antenna would probably be RHCP in one direction and LHCP in the opposite direction! If I wasn't so disabled at present, I' be tempted to build something to experiment with, just because I miss building experimenting with and measuring antennas! Very enjoyable activities for me! Anyway, thanks all for all the commentary and insightful and thought-provoking discussions! Bill's observations seem to suggest something different at work that may deserve some further investigation and exploration! That led me to wondering about circular polarization, or perhaps some rapid high-speed commutation between horizontally polarized and vertically polarized receive antennas. Thanks! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun
Re: Topband: circular polarization on 160m -BTW
I used it on 1296 a bit over 30 years ago, however both ends have to agree on which rotation they will use. I suspect it is more standardized now. And a lot easier to make power than a ring of 7289's with water jackets added! Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Joel Harrison' w...@w5zn.org Cc: d...@prijedor.com; topband@contesting.com; 'Tom W8JI' w...@w8ji.com Sent: Wednesday, February 12, 2014 2:20 PM Subject: Re: Topband: circular polarization on 160m -BTW Thanks, Joel! That makes perfect sense to me! I don’t keep up with EME, as I’m an HF CW DXer, but it seemed that the EME guys might use circular polarization to contend with the Faraday Rotation in Earth’s atmosphere, from my spacecraft days of long ago! Thanks! 73, Charlie, K4OTV From: Joel Harrison [mailto:w...@w5zn.org] Sent: Wednesday, February 12, 2014 2:14 PM To: Charlie Cunningham Cc: Tom W8JI; d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m -BTW Yes, on some of the bands circular polarization is used for EME On Wed, Feb 12, 2014 at 12:47 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: BTW - does anyone know if the EME boys employ circular polarization? 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Wednesday, February 12, 2014 1:35 PM To: 'Tom W8JI'; d...@prijedor.com; topband@contesting.com Subject: Re: Topband: circular polarization on 160m Hello all, My original post regarding circular polarization receiving antennas for 160 was posted 2/2/2014 as a comment on Bill, VE3CSK's post regarding his observation of apparent rapid polarization shifts in the signal received from FT5ZM, on Amsteram Island at their sunrise. Bill was using his K3 in diversity mode to observe the apparent rapid polarization shifts by using both vertical and horizontal receive antennas. The rapid apparent polarization shifts seemed quite different from the slower QSB that we often experience on 160. I post my original hurried off-hand comment and Bill's post below; I wonder what circular-polarized RX antennas might have to offer on 160? Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill and Liz Sent: Sunday, February 02, 2014 8:37 PM To: topband@contesting.com Subject: Topband: FT5ZM SIGNAL I have been listening several evenings now on 160M using my K3 in diversity mode with the TX vertical array on one receiver and a full-wave horizontal loop on the other. I have been struck by the often rapid change in the signal as received on one antenna or the other. As sunrise on Amsterdam approaches this shift becomes quite rapid, with the recovered signal bouncing back and forth ear to ear. Early on, before I began listening in diversity mode, I thought it was rapid QSB taking the signal down into the noise but now realize that it is the angle of the arriving signal which is rapidly changing over the path. No wonder some of the guys have been having problems copying/working the expedition on topband! Bill VE3CSK This seemed to provoke an interesting, lively and informative discussion by a number of people who have explored 160m ionosphere propagation in far greater depth than I have. Some of the commentary piqued my interest and caused me to want to do some more research! Thanks guys, and thanks, Tom, for your recent postings of your recordings from KH6AT etc.! Rather informative and thought-provoking! I must confess that all of my experience with circular polarization has been at UHF (400 MHz range) for spacecraft telemetry and 1.4 GHz for GPS signals. In these cases circular polarization is employed to contend with the Faraday Rotation of signals as they propagate through Earth's atmosphere. These signals generally originate beyond the ionosphere except for a few birds that might pass through the magneto-tail on the lee-side (dark-side) of earth away from the solar wind. Very different from 160m signals that originate on Earth's surface and are reflected from an ionization layer in the ionosphere! Bill's observations are really interesting and seem to suggest something other than the usual slow fades that we are used to on topband. Surely piqued my curiosity! I would think that with proper phase control one could construct circular polarized 160m receive antennas that could be less than full-size if preamps were employed. It's interesting to consider that such an antenna would probably be RHCP in one direction and LHCP in the opposite direction! If I wasn't so disabled at present, I' be tempted to build something to experiment with, just because I miss building experimenting with and measuring antennas! Very enjoyable activities for me! Anyway, thanks all for all the commentary and insightful and thought-provoking discussions! Bill's
Re: Topband: circular polarization on 160m
All, Bah, humbug. We got another 5 inches of snow overnight. We're running out of room to put the snow. At least I can stay inside and play on the radio. Tom makes some good points. Two comments. First, when I said advantage, all I meant was there is less fading on HF when receiving on a circularly polarized antenna. That's the common conclusion of those studies that I referenced. Remember these studies are HF (80-10m), not MF (160m). Second, polarization is not purely random. There is more order to polarization that we generally think due to the ionosphere being immersed in a magnetic field. What's important is where the wave enters and exits the ionosphere - and how well the polarization of the ordinary and extraordinary waves that propagate thru the ionosphere couples to the polarization of your antenna. In my mind that theory translates nicely to the real-world. One of G2HCG's conclusions from his 10m study unwittingly confirmed magneto-ionic theory. I don't think he was even aware of the effect of a magnetic field on a plasma, so that makes his conclusion all the better. Yes, the ionosphere is dynamic and varies over the short-term - so there is some randomness imparted on the what the ionosphere dictates. For the record, G2HCG's conclusion referenced above stated that It was immediately apparent that the number of hops to the ionosphere and back was totally irrelevant. The polarization of signals must therefore be controlled by the last hop. I agree with Herb's comment about implementing a cp antenna on 160m - a very tough job. The big question in my mind would be how do you separate out the difference in vertical patterns when ground is taken into account? Having said all the above, I still say circular polarization on 160m would not be beneficial due to just the ordinary wave being useful. Carl K9LA On Tue, Feb 4, 2014 at 12:03 PM, Tom W8JI w...@w8ji.com wrote: Circular polarization cannot have an advantage on average, or over time. The problem with circular polarization on skywave is the wave has no set rotation, level, or phase. The circular antenna would be fine combining two phase-quadrature fields with a certain lead or lag (depending on rotation or sense), but the arriving signals at HF would be random. They would be just as likely to subtract as to add. Worse, the noise from both systems sums. If you use circular polarization, you are guaranteed a reduction in signal-to-noise the vast majority of time for a small improvement a fraction of the time. This is why microwave links and HF links that have random paths or multiple paths vote with signal-to-noise detectors to pick a single polarization that is optimal at any moment of time. With line-of-sight the signal could have a set, known, repeatable, rotation. With things multi-pathing and bouncing all around, there is no phase or rotation consistency, so they have to vote to the best polarization and ignore the other at any instant. There could also be a system that detects phase and corrects phase to add, but it would have to be a smart system with signal phase correction. In the systems we have, the only practical combining is through stereo diversity. Your brain has to learn to process independent identical phase-locked channels from two different antennas. It does not even have to be polarization differences, spatial differences alone will be enough on HF and MF. For example, two identical Beverage antenna systems here separated maybe 3 wavelengths or more will have entirely different fade times. Signals can be completely out on one, and still workable on the other. Your brain can then learn to sum the independent signals in each ear (if they are phase locked) and make maybe 3-6 dB improvement when both ears have signal, and not be distracted by the left ear noise if only the right ear has signal. Phase coherence is not critical, but lock is. This goes partly away if the channels are not locked. Even 0.1 Hz unlock is deleterious. This ALL goes away if the channels are a few Hz or more out of lock. The advantage goes away if channels are combined, except for seconds or minutes of luck followed by equal times of bad luck. I can sit here and flip switches to parallel channels, either into a receiver or on the output, and these results are repeatable. I can combine dipoles (which by the way are only horizontal broadside to the dipole, tilting to vertical off the ends) and verticals, Beverages and loops, Beverages and Beverages, verticals and Beverages, and it all repeats over and over the same way. I can shift phase between channels bringing wide spaced or cross-polarized systems in matched level and phase, and a few seconds to a few minutes later it is back at 180 out or one channel is adding nothing but noise. I'm afraid just like in commercial systems with scattering or multipath propagation, a circular polarized system is a net detriment. 73 Tom - Original
Re: Topband: circular polarization on 160m
On 2014-02-04 11:02, Herb Schoenbohm wrote: loss of signal results. I would also presume that the construction of a good CP antenna for 160 would be very difficult to perfect. I have seen some antennas for AMSAT work attempting to produce a CP type antenna by have two interlaced yagis, one vertical and the other horizontal, one space 1/4 wave in front of the other, and with a quarter wave delay Herb Schoenbohm, KV4FZ FWIW, I used to know a fellow who got his PhD in antennas working under W8JK at Ohio State University. He worked on a very large HF helix antenna that I believe was circularly polarized. It was basically a cloud warmer pointed straight up. It was suspended from some really large towers. This work was done in the 1950's or 1960's. I don't know what the lower frequency limit of it was. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
I am pretty new to 160 meters, but just got done with a diversity experiment with FT5ZM last night. My results go along with W8JI’s comments. I heard them on 1.8265 at 2215 UT, and then tried to configure my receiver to utilize space diversity, putting my 90 ft vertical in the left ear, and a long EU beverage in my right ear. Rig was a K3 in diversity mode. I plugged the beverage into the aux receiver jack and selected AUX antenna in diversity mode. The vertical was hooked to the main antenna jack on the K3. I had almost 100% copy between 2220 to 2250 UT when I had to QRT. I wish I had more time to listen! It was wild to hear FT5ZM drifting from ear to ear. It took no effort to accomplish this. I knew I was hearing much better. No fades! It seemed to provide a meaningful improvement to my reception of FT5ZM. Highly recommended! I wish I had tried this before! 73 Dave K1WHS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Hi Carl, This has to be the big picture of the system and the goals, and not a narrow picture of what a wave is doing. I think in the big picture we all agree it is useless. First, when I said advantage, all I meant was there is less fading on HF when receiving on a circularly polarized antenna. That's the common conclusion of those studies that I referenced. Remember these studies are HF (80-10m), not MF (160m). While G2HCG likely had circular polarization on ten meters, there isn't much in the WA3's article that actually convines me he was observing circular polarization. If he did have circular polarization, which he probably did have some, it was only basically straight up. This is entirely different than circular polarization at modest or low angles, which is terribly difficult on any lower band. To be circular polarized at modest to low angles, the horizontal antenna would have to somewhat high above ground and broadside to the DX, and the vertically polarized antenna would have to cross the center line of that antenna, or have some planned offset. In other words, it would have to actually be a circular polarized antenna. EZNEC actually provides a way to look at this. At the bottom of the arrow tabs is Desc Options. Click on that, a choice of fields appear that includes circular. The bottom choice, Linear, Maj, Min, gives a relative comparison of circular to linear. Do a Far Field plot and look in the FF Tab on the left for a level comparison between linear and circular fields. I've seen several enthusiastic studies where a lot of time was spent with an antenna that really could not measure what the experimenter concluded he was measuring. Second, polarization is not purely random. There is more order to polarization that we generally think due to the ionosphere being immersed in a magnetic field. What's important is where the wave enters and exits the ionosphere - and how well the polarization of the ordinary and extraordinary waves that propagate thru the ionosphere couples to the polarization of your antenna. In my mind that theory translates nicely to the real-world. One of G2HCG's conclusions from his 10m study unwittingly confirmed magneto-ionic theory. I don't think he was even aware of the effect of a magnetic field on a plasma, so that makes his conclusion all the better. Yes, the ionosphere is dynamic and varies over the short-term - so there is some randomness imparted on the what the ionosphere dictates. For the record, G2HCG's conclusion referenced above stated that It was immediately apparent that the number of hops to the ionosphere and back was totally irrelevant. The polarization of signals must therefore be controlled by the last hop. The first issue is actually creating a circularly polarized antenna at a useful angle that does not deteriorate signal-to-noise. I think that is a very difficult thing to do unless the target is nearly straight up. Most people think grabbing any horizontal antenna and delaying or advancing phase 90 degrees aganst something vertical produces a circular polarized antenna in any direction at any angle. Nothing is further from the truth. A poorly planned antenna might do that in some directions or at some angles in some directions (with or without the 90 shift), but it will also result in pattern tilt and pattern change. Adding signals and noise unpredictably is not a good thing to do. Even if we somehow manage to improve absolute signal level, we can also easily improve noise level just as much or more. I haven't looked at higher bands, but on 160 through 40 adjusting for some optimum mix largely appears to be either a random thing or useless. On most of HF, at least where I have looked, the same. Having said all the above, I still say circular polarization on 160m would not be beneficial due to just the ordinary wave being useful. The bottom line is we are S/N driven on HF, not absolute signal level. What ratio of V to H signal levels do you expect, Carl? What direction is the rotation? I'm assuming this is actually a circular signal, and not something rotating very slowly that is causing fades? 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
In producing a good satellite AMSAT antenna KLM uses the method of quarter wave stagger of two yagis. One is about a quarter wave ahead of the other and fed with a 1/4 wave delay line. To be circular, one is either staggered 1/4 wave forward and they are fed in phase, or they are even without stagger and fed in quadrature. Polar plots of this antenna suggest that they are not really producing a screw sense CP antenna but rather an Axial mode antenna that receives both vertical and horizontal components of the arriving space signal as they occur. That cannot be done. If two antennas are combined without spatial 90 degree stagger **or** phase 90 degree stagger, they are simply a tilted linear polarization. Many people tilt polarization and think it is both V and H, and think it somehow eliminates polarization rotation fading. All they do is tilt the polarization, and 90 degrees from that tilt is a new null. The confusion is because people and programs express polarization from only tow references, V and H. If I tilted a vertical the right amount it would look like a perfect mix of V and H, but it really would be a single polarization tilted at a 45 degree angle. 90 degrees tilt from that angle, say at -45 degrees, would be a null. With different waves and a left tilt we would have: 1.) circular polarized = no improvement at all 2.) slow lazy fading rotation (this is NOT circular) = no improvement at all 3.) polarization tilted at left 45 = a peak response 4.) polarization tilted an -45 degrees = a deep null. To be circularly polarized the wave has to be rotating fast, at the frequency of the wave, so the wave makes one rotation every wave period. This would NOT be a slow fade anyone would hear, it would just be a few dB signal loss. If the wave were slowly rotating, such as to produce a slow fade, the SENSE of the antennas would not matter one bit. You never get the 3 dB back. You would stop the fade from cross polarization, but would also pick up some significant amount of additional noise. I'm not sure how well thought-out or properly conveyed any of this has been, so I'm enjoying the brain exercise. A circularly polarized antenna on 1 MHz cycles through the entire polarization shift in 1uS. A circularly polarized antenna on 1 MHz cycles through one electrical rotation in 1 uS. Anyone here having fading at a 0.5464481 uS rate? If so, the CP antenna will either make fading near infinite or near zero. :) The way I see it is if the rate is not 0.546 uS or so, you do not have circular polarization.You have a slowly rotating wave, and the sense of the RX antenna would be meaningless unless you could time-sync rotation at that slow fading rate. Someone correct me if I am wrong. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Tom ' The way I see it is if the rate is not 0.546 uS or so, you do not have circular polarization.You have a slowly rotating wave, and the sense of the RX antenna would be meaningless unless you could time-sync rotation at that slow fading rate. Someone correct me if I am wrong. 100% correct My system has two WF's, same gain, one vertical and another horizontal, feeding two preamps into IC7800 two receivers. When there is fading on the signal E-W, the time of the rotation from H to V could be long as 5 minutes, most of the time between 1 to 2 minutes. Using M=S on the IC7800 I can keep the two receivers at same frequency, and I can hear one receiver on each ear. I used to QSO Raoul ZS1REC during summer time and sometimes we start the QSO using V pol and finished on H pol.. About the signal noise gain using H and V with two identical receivers, I can say there is no gain at all, when the signal is weak, I switch the other antenna off and hear with only one channel. The advantage to have both is just to avoid listening in the wrong antenna listening on both antennas at the same time. It is not diversity eider because my antennas are only 60 ft. apart . Besides E-W when the signal is coming from less 45 degree and it is fading, I never see rotation, the vertical signal can have a deep QSB and the horizontal signal constant with no QSB. That just happened last Saturday with the FT5ZM, the horizontal signal was solid all the time with no variation on the intensity, however the vertical signal had deep and fast QSB. My take on that is the propagation mode or multi-path, signals can arrive from a refraction out of a duct and or from the same direction but from a different region on the ionosphere. There is no real correlation between the two polarizations signals, in practice they don't mix. It is very different from HF or VHF where the wave is always coming from the same media. Another point is that refraction increase with the decrease square of the in frequency, on 160m the refraction is stronger than 80 or up, as a result it is not necessary to transmit a horizontal signal to answer a horizontal polarized income signal. When the TX signal reach the first refraction point the wave split in two one vertical and another horizontal. What means is the efficiency to couple the TX signal with the atmosphere this is more important than the polarization itself, but 160m only, moving up in frequency the results are completely different, and 30 MHz to 50 MHz it is even special because it is transition from HF to VHF propagation mode. The experiments on 28 MHz does not apply to 1.8 MHz. Between 1 and 2 MHz , everything is different from HF or VHF Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
The way I see it is if the rate is not 0.546 uS or so, you do not have circular polarization.You have a slowly rotating wave, and the sense of the RX antenna would be meaningless unless you could time-sync rotation at that slow fading rate. Someone correct me if I am wrong. 100% correct I hope Carl K9LA has input, but I cannot think of a single way that a circular polarization signal would have fading that would be corrected by changing from a linear polarized antenna to a circular system. This is what perplexes me about any advantage of using a circular RX antenna based on the signal: 1.) If the wave was circularly polarized, that could not cause a fade on a linearly polarized antenna. It rotates far too fast for that. It would just be a steady 3 dB loss. 2.) A slowly rotating signal can go into fades as the electric field crosses the minimum response of an antenna. Making an antenna that responds **in a correct way**, so we don't have a skewed or sloped linear polarization (because that would still fade), might cure that fade. The cure would always be at a S/N penalty for half of the rotation or more. The tradeoff would be a few moments large advantage (during the fade) for a longer time disadvantage. If the horizontal antenna did not have comparable directivity to the vertical, that system could totally hose S/N for all but a very short time, that time being when there would have been no signal. 3.) On VHF, and even ten meters, we can build a directive vertical and horizontal antenna with a good pattern at low wave angles. The wavelength is short enough we can get away from noise, the earth, and have low angle horizontal patterns. But.a linearly polarized antenna would not fade to zero from a rotating wave unless it was rotating slow. The period of rotation for a circularly polarized wave is far too fast for that. I can tune into FM BC circularly polarized signals with linear polarized antenna, either a dipole or vertical, and not have a bit of fading. Any fading would only come from my having the wrong rotation on a circular receiving antenna, or a long term null of response from a very slow rotation. This is what perplexes me...to have fading from polarization it has to rotate slow. That is not a circularly polarized wave by the normal use of the term. If the wave rotates slow, the R-H L-H sense of the antenna makes no difference at all. So why are experimenters hearing slow fade on a linear antenna, and correcting that fade ONLY with a certain L-H or R-H antenna? It was rotating fast enough to be circular, the antenna rotational sense would make zero difference and it would not be fading on a regular single polarization antenna. The wave rotation would, at best, only cause a 3 dB fade into a linearly polarized antenna. This gives me pause about what people are measuring and writing. If they are correct, hundreds of FM BC transmitters need to change their antennas. We have a WA3 claiming the rotational direction makes a difference, that implies the wave is circular. But if the wave were circular, he would not have fading on a linear antenna. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Tom, Perhaps it is much simpler than that. Recalling KL7AJ's article, http://www.nxtbook.com/nxtbooks/arrl/qst_201203/index.php#/42 he states that the magnetic field of the earth splits every HF signal into a right hand or left hand circular wave. Add to that the unevenness of the ionosphere can tilt the wave as well. All this is something that seems that it could cause slow fading. An interesting question, to be sure. Jim - KR9U -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI I hope Carl K9LA has input, but I cannot think of a single way that a circular polarization signal would have fading that would be corrected by changing from a linear polarized antenna to a circular system. This is what perplexes me about any advantage of using a circular RX antenna based on the signal: 1.) If the wave was circularly polarized, that could not cause a fade on a linearly polarized antenna. It rotates far too fast for that. It would just be a steady 3 dB loss. 2.) A slowly rotating signal can go into fades as the electric field crosses the minimum response of an antenna. Making an antenna that responds **in a correct way**, so we don't have a skewed or sloped linear polarization (because that would still fade), might cure that fade. The cure would always be at a S/N penalty for half of the rotation or more. The tradeoff would be a few moments large advantage (during the fade) for a longer time disadvantage. If the horizontal antenna did not have comparable directivity to the vertical, that system could totally hose S/N for all but a very short time, that time being when there would have been no signal. 3.) On VHF, and even ten meters, we can build a directive vertical and horizontal antenna with a good pattern at low wave angles. The wavelength is short enough we can get away from noise, the earth, and have low angle horizontal patterns. But.a linearly polarized antenna would not fade to zero from a rotating wave unless it was rotating slow. The period of rotation for a circularly polarized wave is far too fast for that. I can tune into FM BC circularly polarized signals with linear polarized antenna, either a dipole or vertical, and not have a bit of fading. Any fading would only come from my having the wrong rotation on a circular receiving antenna, or a long term null of response from a very slow rotation. This is what perplexes me...to have fading from polarization it has to rotate slow. That is not a circularly polarized wave by the normal use of the term. If the wave rotates slow, the R-H L-H sense of the antenna makes no difference at all. So why are experimenters hearing slow fade on a linear antenna, and correcting that fade ONLY with a certain L-H or R-H antenna? It was rotating fast enough to be circular, the antenna rotational sense would make zero difference and it would not be fading on a regular single polarization antenna. The wave rotation would, at best, only cause a 3 dB fade into a linearly polarized antenna. This gives me pause about what people are measuring and writing. If they are correct, hundreds of FM BC transmitters need to change their antennas. We have a WA3 claiming the rotational direction makes a difference, that implies the wave is circular. But if the wave were circular, he would not have fading on a linear antenna. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
James You brought a good article about HF propagation, however the behavor on 160m is different from HF. If you check on the KL7A arcticle figure 1 what is happening between 1 and 2 MHz you can see that the green and red does not behaivor the same way as above 2 MHz. This subject is more complex because there us no shirt answer, actualy between 1 and 2 MHz. the ionosphere does not support linear polariration wave. The wave are actualy eliptical and not circular for most directions. You can check the long answer on the must read book from NM7M . R Brown 'The Big Gun's Guied to Low Band Propagation . Magneto-iomic Theory pag 47 to 56 ; and Power coupling pag 57. Thanks to Karl. K9LA, the book is available on his also must read site on the 160m link http://k9la.us/html/160m.html Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Jose, I am only presenting the possibility that if the ionosphere (where 160 propagation happens) isn't uniformly smooth and instead consists of warps, wrinkles and tilts that in a *dynamic ionosphere*, this could be at least one reason we are experiencing slow fades. Elliptical polarization, assuming that it is ever changing, could provide yet another degree of selective fading. I'm don't think I *totally* understand why KL7AJ says that at HF the ionosphere forbids the propagation of linearly polarized signals. If at the magnetic equator, and signals were East to West to equal the earth magnetic tilt of the signals, it seems that at an instance in time that a linear polarized signal could happen.But that may be nit picking. Jim - KR9U From: JC N4IS [mailto:n...@comcast.net] Sent: Wednesday, February 05, 2014 10:45 PM To: jbw...@comcast.net; 'Tom W8JI'; he...@vitelcom.net; topband@contesting.com Subject: RE: Topband: circular polarization on 160m James You brought a good article about HF propagation, however the behavor on 160m is different from HF. If you check on the KL7A arcticle figure 1 what is happening between 1 and 2 MHz you can see that the green and red does not behaivor the same way as above 2 MHz. This subject is more complex because there us no shirt answer, actualy between 1 and 2 MHz. the ionosphere does not support linear polariration wave. The wave are actualy eliptical and not circular for most directions. You can check the long answer on the must read book from NM7M . R Brown 'The Big Gun's Guied to Low Band Propagation . Magneto-iomic Theory pag 47 to 56 ; and Power coupling pag 57. Thanks to Karl. K9LA, the book is available on his also must read site on the 160m link http://k9la.us/html/160m.html Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: circular polarization on 160m
Circular polarization cannot have an advantage on average, or over time. The problem with circular polarization on skywave is the wave has no set rotation, level, or phase. The circular antenna would be fine combining two phase-quadrature fields with a certain lead or lag (depending on rotation or sense), but the arriving signals at HF would be random. They would be just as likely to subtract as to add. Worse, the noise from both systems sums. If you use circular polarization, you are guaranteed a reduction in signal-to-noise the vast majority of time for a small improvement a fraction of the time. This is why microwave links and HF links that have random paths or multiple paths vote with signal-to-noise detectors to pick a single polarization that is optimal at any moment of time. With line-of-sight the signal could have a set, known, repeatable, rotation. With things multi-pathing and bouncing all around, there is no phase or rotation consistency, so they have to vote to the best polarization and ignore the other at any instant. There could also be a system that detects phase and corrects phase to add, but it would have to be a smart system with signal phase correction. In the systems we have, the only practical combining is through stereo diversity. Your brain has to learn to process independent identical phase-locked channels from two different antennas. It does not even have to be polarization differences, spatial differences alone will be enough on HF and MF. For example, two identical Beverage antenna systems here separated maybe 3 wavelengths or more will have entirely different fade times. Signals can be completely out on one, and still workable on the other. Your brain can then learn to sum the independent signals in each ear (if they are phase locked) and make maybe 3-6 dB improvement when both ears have signal, and not be distracted by the left ear noise if only the right ear has signal. Phase coherence is not critical, but lock is. This goes partly away if the channels are not locked. Even 0.1 Hz unlock is deleterious. This ALL goes away if the channels are a few Hz or more out of lock. The advantage goes away if channels are combined, except for seconds or minutes of luck followed by equal times of bad luck. I can sit here and flip switches to parallel channels, either into a receiver or on the output, and these results are repeatable. I can combine dipoles (which by the way are only horizontal broadside to the dipole, tilting to vertical off the ends) and verticals, Beverages and loops, Beverages and Beverages, verticals and Beverages, and it all repeats over and over the same way. I can shift phase between channels bringing wide spaced or cross-polarized systems in matched level and phase, and a few seconds to a few minutes later it is back at 180 out or one channel is adding nothing but noise. I'm afraid just like in commercial systems with scattering or multipath propagation, a circular polarized system is a net detriment. 73 Tom - Original Message - From: Carl Luetzelschwab carlluetzelsch...@gmail.com To: topband@contesting.com Sent: Monday, February 03, 2014 12:16 PM Subject: Topband: circular polarization on 160m I hope everyone has had a chance to work FT5ZM on topband. With respect to circular polarization on our HF bands (3.5 - 28 MHz) and on 6m, theory says both the ordinary and extraordinary waves propagate thru the ionosphere with pretty much equal ionospheric absorption. Thus circularly polarized antennas can provide an advantage. Some of the real-world examples I'm aware of have been documented by G2HCG on 10m (in the old Communications Quarterly), by the original K6CT on 20m (in the RSGB Bulletin) and by WA3WDR on 75m (a web paper). I'm sure there are others out there, too. On 160m, theory says the extraordinary wave incurs much more ionospheric absorption (more heavily attenuated) due to 1.8 MHz being so close to the electron-gyro frequency. Thus in theory only the ordinary wave is useful on 160m, which says circular polarization wouldn't do any good. Now things happen on 160m in the real-world that we simply don't understand. For example, an ordinary wave can excite an extraordinary wave under certain ionospheric conditions (if you'd like to read more, curl up in a warm place on a cold night with Chapter 3 in Ionospheric Radio by Kenneth Davies). Could this be happening? I don't think we can rule it out. In my opinion based on all the reports on this reflector over the years, it seems to me that having selectable elevation angles is more important than polarization. But I also admit that there hasn't been much work in the polarization field (no pun intended) on 160m (except for N4IS with his horizontal Waller flag - which makes sense with theory for roughly East-West propagation close to the geomagnetic equator). Carl K9LA _ Topband Reflector Archives -
Re: Topband: circular polarization on 160m
Hi Carl and top-band lovers I would like to mention Chapter 7.6 as well, polarization matching, and also 7.7 Fading. I started developing my HWF early 2009 and I think there is no more to squeeze from it. Here some update in respect of polarization on 160m. It is a game!, vertical and horizontal field changes all the time, an elliptic can describe better the waves on 160m. My last HWF tuning gave me another 6-8 db improvement on the signal noise ratio. The HWF is really an all directions noise cancelling antenna ( Va-Vb=0), the goal is maximum attenuation on the vertical field an good directivity on the horizontal field. The takeoff angle is always the same and does not change with the height above ground ,it always very close to 40 degree. It is alike high horizontal dipole that takeoff change with the height from ground. The HWF has a deep null from high angle signals at any height above ground. The game is maximum attention on the vertical signal because most of the manmade noise, power line noise, city noise propagate with vertical polarization due the proximity with the ground for 160m waves. For 160m the HWF needs to be over 100 ft. to perform well on the horizontal signals, 50 ft. is ok for 80m and up. The HWF works 160m to 30m with excellent performance depending on the area of the loops. The HWF gain is around -43 db, and the vertical attenuation can be adjusted to deep another -50db, the total attenuation front and back is -90 db , It has a front null and a back null for vertical signals. This is a weak, weak, weak signal system implementation, very complex by nature by receiving near the receiver noise floor most of the time. Depending on the direction of the wave the H/V ratio can be -20 db or more both ways, most of the time the vertical component is 10 to 20 db stronger than the horizontal component. When you combine the 4 variables, vertical gain, horizontal gain, vertical noise QRM and the signal H/V ratio you have your final signal to noise ratio, however on top of that you need to add the propagation noise as well. Another dependence is the solar cycle. We are at the peak of the solar cycle and the propagation this year has been very different . Long pass is peaking at the SS or SR and the signals from North are showing a strong horizontal component. or it could be just coincidence, just time will tell. Nowadays I can copy better weak signals with my HWV than my VWF in all directions. I just observed that recently with 8Q7BM, NH0Z,V63DX,4J6RO, 4K6FO and 4L5O, signals from NNW and NNE better on HWF. It is the first time I can hear better signals coming North with the HWF. It is all about signal noise ratio. For long path the new adjust also helped a lot. I detuned the TX tower to minimum noise on the HWF, making the diagram symmetrical on the polar plot. It looks like a butterfly for local vertical signals. Peter HS0ZKX is coming strong from SSW every 28 days. Just after the solstice last month the long path propagation was just fantastic. WV8. H40,RA0. JA. BA. BG and DU7 copy with Q5 from SSW from Dec 25th to Jan 1st , but few QSO's. only JA and DU7 on the log. FT5ZM only on the HWF as well. I agree with Carl. There hasn't been much work in polarization field on 160m, however It is a fascinate subject. Come on in folks! Regards JCarlos N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Luetzelschwab Sent: Monday, February 03, 2014 12:17 PM To: topband@contesting.com Subject: Topband: circular polarization on 160m I hope everyone has had a chance to work FT5ZM on topband. With respect to circular polarization on our HF bands (3.5 - 28 MHz) and on 6m, theory says both the ordinary and extraordinary waves propagate thru the ionosphere with pretty much equal ionospheric absorption. Thus circularly polarized antennas can provide an advantage. Some of the real-world examples I'm aware of have been documented by G2HCG on 10m (in the old Communications Quarterly), by the original K6CT on 20m (in the RSGB Bulletin) and by WA3WDR on 75m (a web paper). I'm sure there are others out there, too. On 160m, theory says the extraordinary wave incurs much more ionospheric absorption (more heavily attenuated) due to 1.8 MHz being so close to the electron-gyro frequency. Thus in theory only the ordinary wave is useful on 160m, which says circular polarization wouldn't do any good. Now things happen on 160m in the real-world that we simply don't understand. For example, an ordinary wave can excite an extraordinary wave under certain ionospheric conditions (if you'd like to read more, curl up in a warm place on a cold night with Chapter 3 in Ionospheric Radio by Kenneth Davies). Could this be happening? I don't think we can rule it out. In my opinion based on all the reports on this reflector over the years, it seems to me that having selectable elevation angles is more important than polarization. But I also admit that there hasn't
Re: Topband: circular polarization on 160m
Is there not a built in loss of 3db on both TX and RX with a CP antenna compared to an Axial mode antenna? Not that it makes that much difference on RX but 3db is 3db. Another issue with CP I understand is the difference between LHCP and RHCP for space communications is supposed to be infinity for space communications. I do not know if the same rules apply for HF with skip involved. Although I have seen this on terrestrial UHF paths when the screw sense is reversed and a complete loss of signal results. I would also presume that the construction of a good CP antenna for 160 would be very difficult to perfect. I have seen some antennas for AMSAT work attempting to produce a CP type antenna by have two interlaced yagis, one vertical and the other horizontal, one space 1/4 wave in front of the other, and with a quarter wave delay line at the feed point separating each. If this could be replicated between a TB horizontal vertical and a horizontal dipole some distance away...I just don't know if this would even end up providing a CP wave front. If they were far enough apart maybe there would be some diversity gain./ Herb Schoenbohm, KV4FZ On 2/4/2014 1:03 PM, Tom W8JI wrote: Circular polarization cannot have an advantage on average, or over time. The problem with circular polarization on skywave is the wave has no set rotation, level, or phase. The circular antenna would be fine combining two phase-quadrature fields with a certain lead or lag (depending on rotation or sense), but the arriving signals at HF would be random. They would be just as likely to subtract as to add. Worse, the noise from both systems sums. If you use circular polarization, you are guaranteed a reduction in signal-to-noise the vast majority of time for a small improvement a fraction of the time. This is why microwave links and HF links that have random paths or multiple paths vote with signal-to-noise detectors to pick a single polarization that is optimal at any moment of time. With line-of-sight the signal could have a set, known, repeatable, rotation. With things multi-pathing and bouncing all around, there is no phase or rotation consistency, so they have to vote to the best polarization and ignore the other at any instant. There could also be a system that detects phase and corrects phase to add, but it would have to be a smart system with signal phase correction. In the systems we have, the only practical combining is through stereo diversity. Your brain has to learn to process independent identical phase-locked channels from two different antennas. It does not even have to be polarization differences, spatial differences alone will be enough on HF and MF. For example, two identical Beverage antenna systems here separated maybe 3 wavelengths or more will have entirely different fade times. Signals can be completely out on one, and still workable on the other. Your brain can then learn to sum the independent signals in each ear (if they are phase locked) and make maybe 3-6 dB improvement when both ears have signal, and not be distracted by the left ear noise if only the right ear has signal. Phase coherence is not critical, but lock is. This goes partly away if the channels are not locked. Even 0.1 Hz unlock is deleterious. This ALL goes away if the channels are a few Hz or more out of lock. The advantage goes away if channels are combined, except for seconds or minutes of luck followed by equal times of bad luck. I can sit here and flip switches to parallel channels, either into a receiver or on the output, and these results are repeatable. I can combine dipoles (which by the way are only horizontal broadside to the dipole, tilting to vertical off the ends) and verticals, Beverages and loops, Beverages and Beverages, verticals and Beverages, and it all repeats over and over the same way. I can shift phase between channels bringing wide spaced or cross-polarized systems in matched level and phase, and a few seconds to a few minutes later it is back at 180 out or one channel is adding nothing but noise. I'm afraid just like in commercial systems with scattering or multipath propagation, a circular polarized system is a net detriment. 73 Tom - Original Message - From: Carl Luetzelschwab carlluetzelsch...@gmail.com To: topband@contesting.com Sent: Monday, February 03, 2014 12:16 PM Subject: Topband: circular polarization on 160m I hope everyone has had a chance to work FT5ZM on topband. With respect to circular polarization on our HF bands (3.5 - 28 MHz) and on 6m, theory says both the ordinary and extraordinary waves propagate thru the ionosphere with pretty much equal ionospheric absorption. Thus circularly polarized antennas can provide an advantage. Some of the real-world examples I'm aware of have been documented by G2HCG on 10m (in the old Communications Quarterly), by the original K6CT on 20m (in the RSGB Bulletin) and by WA3WDR on 75m (a web paper). I'm sure there are others out
Re: Topband: circular polarization on 160m
Is there not a built in loss of 3db on both TX and RX with a CP antenna compared to an Axial mode antenna? Not that it makes that much difference on RX but 3db is 3db. Another issue with CP I understand is the difference between LHCP and RHCP for space communications is supposed to be infinity for space communications. I do not know if the same rules apply for HF with skip involved. Although I have seen this on terrestrial UHF paths when the screw sense is reversed and a complete loss of signal results. I would also presume that the construction of a good CP antenna for 160 would be very difficult to perfect. I have seen some antennas for AMSAT work attempting to produce a CP type antenna by have two interlaced yagis, one vertical and the other horizontal, one space 1/4 wave in front of the other, and with a quarter wave delay line at the feed point separating each. If this could be replicated between a TB horizontal vertical and a horizontal dipole some distance away...I just don't know if this would even end up providing a CP wave front. If they were far enough apart maybe there would be some diversity gain./ Herb Schoenbohm, KV4FZ On 2/4/2014 1:03 PM, Tom W8JI wrote: Circular polarization cannot have an advantage on average, or over time. The problem with circular polarization on skywave is the wave has no set rotation, level, or phase. The circular antenna would be fine combining two phase-quadrature fields with a certain lead or lag (depending on rotation or sense), but the arriving signals at HF would be random. They would be just as likely to subtract as to add. Worse, the noise from both systems sums. If you use circular polarization, you are guaranteed a reduction in signal-to-noise the vast majority of time for a small improvement a fraction of the time. This is why microwave links and HF links that have random paths or multiple paths vote with signal-to-noise detectors to pick a single polarization that is optimal at any moment of time. With line-of-sight the signal could have a set, known, repeatable, rotation. With things multi-pathing and bouncing all around, there is no phase or rotation consistency, so they have to vote to the best polarization and ignore the other at any instant. There could also be a system that detects phase and corrects phase to add, but it would have to be a smart system with signal phase correction. In the systems we have, the only practical combining is through stereo diversity. Your brain has to learn to process independent identical phase-locked channels from two different antennas. It does not even have to be polarization differences, spatial differences alone will be enough on HF and MF. For example, two identical Beverage antenna systems here separated maybe 3 wavelengths or more will have entirely different fade times. Signals can be completely out on one, and still workable on the other. Your brain can then learn to sum the independent signals in each ear (if they are phase locked) and make maybe 3-6 dB improvement when both ears have signal, and not be distracted by the left ear noise if only the right ear has signal. Phase coherence is not critical, but lock is. This goes partly away if the channels are not locked. Even 0.1 Hz unlock is deleterious. This ALL goes away if the channels are a few Hz or more out of lock. The advantage goes away if channels are combined, except for seconds or minutes of luck followed by equal times of bad luck. I can sit here and flip switches to parallel channels, either into a receiver or on the output, and these results are repeatable. I can combine dipoles (which by the way are only horizontal broadside to the dipole, tilting to vertical off the ends) and verticals, Beverages and loops, Beverages and Beverages, verticals and Beverages, and it all repeats over and over the same way. I can shift phase between channels bringing wide spaced or cross-polarized systems in matched level and phase, and a few seconds to a few minutes later it is back at 180 out or one channel is adding nothing but noise. I'm afraid just like in commercial systems with scattering or multipath propagation, a circular polarized system is a net detriment. 73 Tom - Original Message - From: Carl Luetzelschwab carlluetzelsch...@gmail.com To: topband@contesting.com Sent: Monday, February 03, 2014 12:16 PM Subject: Topband: circular polarization on 160m I hope everyone has had a chance to work FT5ZM on topband. With respect to circular polarization on our HF bands (3.5 - 28 MHz) and on 6m, theory says both the ordinary and extraordinary waves propagate thru the ionosphere with pretty much equal ionospheric absorption. Thus circularly polarized antennas can provide an advantage. Some of the real-world examples I'm aware of have been documented by G2HCG on 10m (in the old Communications Quarterly), by the original K6CT on 20m (in the RSGB Bulletin) and by WA3WDR on 75m (a web paper). I'm sure there are others out
