Re: Topband: K levels and skew path on 160
I was rereading the article by Cary Oler and Ted Cohen (N4XX), published in 1998, which provided a good primer for understanding, as much as we can, propagation on Topband. In one section the impact of a high K index on the auroral oval, and its subsequent impact on signals passing through the oval, was discussed. My question is does the K index, especially at higher levels, impact the SW or SSW skew path many of us were trying to use this morning to work Ken, XW4ZW? Any information or observations will be appreciated. Best, Steve, From my location now, and when I was in Ohio, it was quite normal for any signal passing near or through the north magnetic pole to never make it through via the direct path. When signals were heard, they were always skewed in some other direction. The only exception seems to be when sunspots and geomagnetic activity are very low. In this very last solar minimum, when sunspots were absent, many stations would appear via north. Of course that gave the northern NA stations nearly north of me a clear advantage, because they were closer. My policy is to not worry about predicting or expecting anything, and I rarely even look at solar activity. I just listen in all dark directions when the station is almost on the opposite side of the world, especially when he is anywhere near the equator and far,far, away. :) 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K levels and skew path on 160
From mid-November through mid-February, daylight over Antarctica and the Southern Ocean prevents the 160 meter long path from propagating due south (+/- about 20 degrees). Except for sunspot minimum, short path propagation transiting only the northern hemisphere to southeast Asia is very uncommon from the eastern USA. 160 and 80 meter propagation from eastern USA to southeast Asia is most likely to follow the SSE evening and SSW sunrise gray lines, although as Tom says, its best to listen for the actual path. From 1145-1300Z (the likely times for long path propagation to southeast Asia during eastern USA morning) the gray line passes approximately through HC8, so the long path is likely to be SSW or possibly SW Because the southern magnetic pole is just off the coast of Antarctica and directly south of Australia, the SSW long path crosses through the auroral belt and this long path is significantly affected by geomagnetic activity. From 2300-2330Z (the most likely times for southeast Asia long path in eastern USA evening) the grey line crosses Uruguay, so the long path to southeast Asia is likely to be SSE or possibly SE. Because the southern magnetic pole is on the opposite side of Antarctica, the SSE long path is much less affected by geomagnetic conditions than the 1145-1300Z SSW long path. 73 Frank W3LPL - Original Message - From: Tom W8JI w...@w8ji.com To: Steven R Daniel, D.D.S. n...@comcast.net, topband@contesting.com Sent: Tuesday, January 27, 2015 7:21:00 PM Subject: Re: Topband: K levels and skew path on 160 I was rereading the article by Cary Oler and Ted Cohen (N4XX), published in 1998, which provided a good primer for understanding, as much as we can, propagation on Topband. In one section the impact of a high K index on the auroral oval, and its subsequent impact on signals passing through the oval, was discussed. My question is does the K index, especially at higher levels, impact the SW or SSW skew path many of us were trying to use this morning to work Ken, XW4ZW? Any information or observations will be appreciated. Best, Steve, From my location now, and when I was in Ohio, it was quite normal for any signal passing near or through the north magnetic pole to never make it through via the direct path. When signals were heard, they were always skewed in some other direction. The only exception seems to be when sunspots and geomagnetic activity are very low. In this very last solar minimum, when sunspots were absent, many stations would appear via north. Of course that gave the northern NA stations nearly north of me a clear advantage, because they were closer. My policy is to not worry about predicting or expecting anything, and I rarely even look at solar activity. I just listen in all dark directions when the station is almost on the opposite side of the world, especially when he is anywhere near the equator and far,far, away. :) 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: K levels and skew path on 160
I was rereading the article by Cary Oler and Ted Cohen (N4XX), published in 1998, which provided a good primer for understanding, as much as we can, propagation on Topband. In one section the impact of a high K index on the auroral oval, and its subsequent impact on signals passing through the oval, was discussed. My question is does the K index, especially at higher levels, impact the SW or SSW skew path many of us were trying to use this morning to work Ken, XW4ZW? Any information or observations will be appreciated. Best, Steve, NN4T _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: K levels and skew path on 160
-Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of donov...@starpower.net Sent: Tuesday, January 27, 2015 3:28 PM To: topband@contesting.com Cc: n...@comcast.net Because the southern magnetic pole is just off the coast of Antarctica and directly south of Australia, the SSW long path crosses through the auroral belt and this long path is significantly affected by geomagnetic activity. From 2300-2330Z (the most likely times for southeast Asia long path in eastern USA evening) the grey line crosses Uruguay, so the long path to southeast Asia is likely to be SSE or possibly SE. Because the southern magnetic pole is on the opposite side of Antarctica, the SSE long path is much less affected by geomagnetic conditions than the 1145-1300Z SSW long path. Frank Your observations match my observations since 2009 when I started to work with Horizontal polarized receiver antenna for 80/160. 2010 and 2011 the SSE/SSW path was open most of the days. Peter (XU7ACY) was very active and I heard him from October to March over 60 days out of 180 days on 160m, and every single day on 80m at the same operating time you mentioned. I did try to correlate the openings with K and AL and it is not directly related. The only index for magnetic storm that was correlated was Dst. Dst index is an index of magnetic activity derived from a network of near-equatorial geomagnetic observatories that measures the intensity of the globally symmetrical equatorial electrojet (the ring current). I started to follow Dst because Alan Melia G3NYK long wave propagation page. Alan noticed the LF ( 500KHz) propagation could be good after few days of Dst above zero, it means low activity of magnetic storm. K, AL and Dst and all related with solar wind speed, predictions are available from Colorado and Kyoto. http://lasp.colorado.edu/space_weather/dsttemerin/dsttemerin.html http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/presentmonth/index.html The Dst can be useful when is positive for 5 or more days, indicating good condition possibility. Activity is more important than possibility, without activity propagation does not matter. So when a flare or CME hit the magnetic ring, two things happen, first there is a very good improvement on the propagation for few hours followed by a depression and degradation of propagation, that depression last for several days and a good recovery can take over a week. After the impact the attenuation is high above normal and the impact on 160m is significate, but not much on 80m. After a good success with HWF in Florida, some friends in South America, and Brazil started to use the HWF for long path. I get very serious trying to understand the physics behind 50% openings on LP and I collect data from previous QSO on 80 and 160m when directive RX antenna systems was used. For my surprise all opening on the South Hemisphere long path were actually NNW NNE. That result indicate that the actual signal SSE SSW get refracted at the equator region and travel inside the darkness. Robert DU7ET was a good example of this kind of propagation long path , we had QSO's every month from Jan to July 2013. For me all openings were SSW but from my friends on Brazil the path was NNW. Based on the observations my conclusion (still a work in progress) is that the signal does not reach the south pole auroral belt. It's run along the equator, That s why I am calling this propagation mode TELP , Trans Equatorial Long Path. Carl K9LA did a nice paper with the ray traces from my location to XU7 , and at 40 degree there is a refraction bending SSW signal to W. It can explain the same bending for reflated signals NNW to W from Brazil. Dst also can show how bad the propagation was Dec 2014 to middle Jan 2015. Ove several years the Dst was in between 0 and -20 but during the last two month Dst was between -20 and -40 with very deeps near -100. I would say that TELP I open on 80m almost every day, we just don't have much activity to understand it better. Regards JC N4IS - Original Message - From: Tom W8JI w...@w8ji.com To: Steven R Daniel, D.D.S. n...@comcast.net, topband@contesting.com Sent: Tuesday, January 27, 2015 7:21:00 PM Subject: Re: Topband: K levels and skew path on 160 I was rereading the article by Cary Oler and Ted Cohen (N4XX), published in 1998, which provided a good primer for understanding, as much as we can, propagation on Topband. In one section the impact of a high K index on the auroral oval, and its subsequent impact on signals passing through the oval, was discussed. My question is does the K index, especially at higher levels, impact the SW or SSW skew path many of us were trying to use this morning to work Ken, XW4ZW? Any information or observations will be appreciated. Best, Steve, From my location now, and when I was in Ohio, it was quite normal for any signal passing near or through the north magnetic pole to never make
Re: Topband: K levels and skew path on 160
Hi JC, Thanks for your interesting email. You may be correct that SSE/SSW long path propagation may not extend very far into the southern hemisphere. I wasn't aware of the NNE/NNW observations by our southern hemisphere friends. It also appears that SSE/SSW long path is more reliable for more southerly locations in the USA than it is for higher latitude locations. Unfortunately there usually isn't enough activity in southeast asia for us to make regular observations, you were fortunate to be able to have long term observations with XU7ACY and DU7ET . Thanks 73 Frank W3LPL - Original Message - From: JC n...@comcast.net To: donov...@starpower.net, topband@contesting.com Cc: n...@comcast.net Sent: Wednesday, January 28, 2015 2:45:05 AM Subject: RE: Topband: K levels and skew path on 160 -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of donov...@starpower.net Sent: Tuesday, January 27, 2015 3:28 PM To: topband@contesting.com Cc: n...@comcast.net Because the southern magnetic pole is just off the coast of Antarctica and directly south of Australia, the SSW long path crosses through the auroral belt and this long path is significantly affected by geomagnetic activity. From 2300-2330Z (the most likely times for southeast Asia long path in eastern USA evening) the grey line crosses Uruguay, so the long path to southeast Asia is likely to be SSE or possibly SE. Because the southern magnetic pole is on the opposite side of Antarctica, the SSE long path is much less affected by geomagnetic conditions than the 1145-1300Z SSW long path. Frank Your observations match my observations since 2009 when I started to work with Horizontal polarized receiver antenna for 80/160. 2010 and 2011 the SSE/SSW path was open most of the days. Peter (XU7ACY) was very active and I heard him from October to March over 60 days out of 180 days on 160m, and every single day on 80m at the same operating time you mentioned. I did try to correlate the openings with K and AL and it is not directly related. The only index for magnetic storm that was correlated was Dst. Dst index is an index of magnetic activity derived from a network of near-equatorial geomagnetic observatories that measures the intensity of the globally symmetrical equatorial electrojet (the ring current). I started to follow Dst because Alan Melia G3NYK long wave propagation page. Alan noticed the LF ( 500KHz) propagation could be good after few days of Dst above zero, it means low activity of magnetic storm. K, AL and Dst and all related with solar wind speed, predictions are available from Colorado and Kyoto. http://lasp.colorado.edu/space_weather/dsttemerin/dsttemerin.html http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/presentmonth/index.html The Dst can be useful when is positive for 5 or more days, indicating good condition possibility. Activity is more important than possibility, without activity propagation does not matter. So when a flare or CME hit the magnetic ring, two things happen, first there is a very good improvement on the propagation for few hours followed by a depression and degradation of propagation, that depression last for several days and a good recovery can take over a week. After the impact the attenuation is high above normal and the impact on 160m is significate, but not much on 80m. After a good success with HWF in Florida, some friends in South America, and Brazil started to use the HWF for long path. I get very serious trying to understand the physics behind 50% openings on LP and I collect data from previous QSO on 80 and 160m when directive RX antenna systems was used. For my surprise all opening on the South Hemisphere long path were actually NNW NNE. That result indicate that the actual signal SSE SSW get refracted at the equator region and travel inside the darkness. Robert DU7ET was a good example of this kind of propagation long path , we had QSO's every month from Jan to July 2013. For me all openings were SSW but from my friends on Brazil the path was NNW. Based on the observations my conclusion (still a work in progress) is that the signal does not reach the south pole auroral belt. It's run along the equator, That s why I am calling this propagation mode TELP , Trans Equatorial Long Path. Carl K9LA did a nice paper with the ray traces from my location to XU7 , and at 40 degree there is a refraction bending SSW signal to W. It can explain the same bending for reflated signals NNW to W from Brazil. Dst also can show how bad the propagation was Dec 2014 to middle Jan 2015. Ove several years the Dst was in between 0 and -20 but during the last two month Dst was between -20 and -40 with very deeps near -100. I would say that TELP I open on 80m almost every day, we just don't have much activity to understand it better. Regards JC N4IS - Original Message - From: Tom
