Re: Topband: 160m activity and propagation
VP8PJ, in South Orkney is a 559 here tonight. A new one on 160 & my only other S. Orkney Q was on 15M in 1990. Amazingly it took two calls and he came back so N/S propagation is excellent right now. 73, Gary KA1J _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Bev flex high noise troubleshooting
On 2/23/2020 2:37 PM, WW3S wrote: I assume my next step would be to check all the coax feed lines, what would be the best way to do that? Hi Jamie, That's almost always one of the first things to check. I'd start with a visual inspection, then an ohmmeter check, and a TDR swept from 50-500 MHz. What type of coax and connectors? How were the connectors installed? Has anything gotten wet? Chewed by varmints? TDR might show that. Another possibility is that there's one or more new noise sources in your neighborhood. There can also be common mode noise pickup on the coax. Best practice is to have a serious common mode choke on both ends. http://k9yc.com/RXChokesTransformers.pdf 73, Jim K9YC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Bev flex high noise troubleshooting
I noticed during the arrl contest my ewe configured bev flex seemed to have a higher than normal noise level. It’s gotten worse. I checked and rechecked all connections, and reterminated them. Still high noise. I assume my next step would be to check all the coax feed lines, what would be the best way to do that? Also open to any other troubleshooting tips Sent from my iPad _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 160m activity and propagation
I suspect that you are exactly right, Jim. :-) On Sun, Feb 23, 2020, 12:51 PM Jim Brown wrote: > > I suspect much of the difference may be RX noise levels at both ends of > the path. The number of RX noise sources has mushroomed over the past > decade, with SMPS, variable speed motor controllers, solar systems, and > the bean counters at power utilities that down-prioritize the > maintenance of their distribution lines. > > 73, Jim K9YC > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 160m activity and propagation
On 2/23/2020 5:09 AM, W7RH wrote: The emphasis of my questions are based on European propagation path perceived differences since last solar minimum. I suspect much of the difference may be RX noise levels at both ends of the path. The number of RX noise sources has mushroomed over the past decade, with SMPS, variable speed motor controllers, solar systems, and the bean counters at power utilities that down-prioritize the maintenance of their distribution lines. 73, Jim K9YC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: 160m activity and propagation
In the previous minimum I could work North West USA and West Canada almost every day. Now it is rare. The path to southwest USA and Carribean is better. 73 Henk PA5KT Op 23-2-2020 om 14:09 schreef W7RH: The emphasis of my questions are based on European propagation path perceived differences since last solar minimum. One thing I am not is a Geophysicist, I have no training there. My comments are on perceived changes in the aurora ring density as viewed from my location in Arizona that would have been in the past much lower on the path towards Europe far more often than present. I'll call it prime time wipe out. Very small changes in solar wind have had a profound effect. Whether the center point is the magnetic north pole or the Geomagnetic pole I have no idea as both have migrated with the Magnetic North pole the greatest at a rate of 30 miles per year and increasing. Perhaps the reduction of magnetic field over North America and increased gamma radiation create the effect. In a related article it stated the magnetic field over North America is 15% less than it was in 2015. https://www.livescience.com/46694-magnetic-field-weakens.html https://www.hist-geo-space-sci.net/5/175/2014/ Trying to get a better grasp of what is going on. 73 Bob W7RH _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: 160m activity and propagation
The emphasis of my questions are based on European propagation path perceived differences since last solar minimum. One thing I am not is a Geophysicist, I have no training there. My comments are on perceived changes in the aurora ring density as viewed from my location in Arizona that would have been in the past much lower on the path towards Europe far more often than present. I'll call it prime time wipe out. Very small changes in solar wind have had a profound effect. Whether the center point is the magnetic north pole or the Geomagnetic pole I have no idea as both have migrated with the Magnetic North pole the greatest at a rate of 30 miles per year and increasing. Perhaps the reduction of magnetic field over North America and increased gamma radiation create the effect. In a related article it stated the magnetic field over North America is 15% less than it was in 2015. https://www.livescience.com/46694-magnetic-field-weakens.html https://www.hist-geo-space-sci.net/5/175/2014/ Trying to get a better grasp of what is going on. 73 Bob W7RH -- W7RH DM35os "It has become appallingly obvious that our technology has exceeded our humanity." - Albert Einstein _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
