By Arnie Coro
radio amateur CO2KK
Hola amigos radioaficionados all around the world.. this is Dxers Unlimited’s middle of the week edition with yours truly Arnie Coro as your host.. Here is now news item one… a very interesting report
DXCC COUNTRY/ENTITY REPORT: According to the AR-Cluster Network for the week of Sunday, 26th-August, through Sunday, 2nd-September there were 213 countries active. And I guess that this good results have something to do with the FT8 digital communications mode now in use around the world making possible two way contacts under extremely poor propagation conditions…
The South African Radio League (SARL) say the past weekend, Radio Amateurs reported that they experienced periods of radio black-out which lasted 24 hours.
When a strong enough solar flare occurs, ionisation is produced in the lower, more dense layers of the ionosphere (the D-layer), and radio waves that interact with electrons in layers lose energy due to the more frequent collisions that occur in the higher density environment of the D-layer. This can cause HF radio signals to become degraded or completely absorbed. This results in a radio blackout, the absence of HF communication, primarily impacting the 3 to 30 MHz band.
HamSci (Hamradio Science Citizen Investigation) is a USA based group of radio amateurs and scientists who work together to study various aspects of radio science. During this weekend’s event they found that the solar and the planetary field united and created a hole that let plasma inside the magnetosphere of the planet create severe auroras.
The fast-growing sunspot (AR270) has a reversed polarity which would link it as the first sunspot of the next solar cycle. The solar cycle is an average of 11 years. The current cycle (cycle 24) still has approximate 2 years to go before it is expected to reach its minimum and cycle 25 to start. The question HamSCI is asking was this just a single event or are we truly entering cycle 25?
Whatever hit Earth was not proton flux which is associated with CMEs and coronal holes. The storm was created by fast compression of earth’s magnetic field and the sudden release of magnetic pressure from the Sun. This whiplash created a vacuum which sucked in the plasma surrounding the planet and at the same time caused the geomagnetic activity to rise to a G3 strong storm level. Other sources are forecasting a much earlier than expected solar minimum, making cycle 24 one of the shortest on record.
Espeleologists, the scientists that do research about caves and caverns make use of a transceiver known as the HeyPhone that is a 17-year-old design from British radio amateur John Hey, G3TDZ who passed away some time ago so he didn’t get to see his design play a role in the most recent high profile cave rescue that took place in Thailand, although it has apparently been a part of many others in the past. The HeyPhone is actually considered obsolete but is still in service with some espeleology teams.
The radio uses USB upper sideband voice operating at the very low frequency of 87 kHz. The low frequency can penetrate deep into the ground using either induction loop antennas like the older Mole-phone, or — more commonly — with electrodes driven into the ground to inject RF energy directly into the surrounding area. What is interesting is that in today’s world, people take wireless communications for granted and don’t realize that cell phones don’t work underground or in the face of wide-spread disasters when the cell towers fail or the cell system is overloaded with traffic that it can not handle.
More solar cycles predictions and forecast now circulating …. one of the latest ones says that cycle 25 is now coming to an end… after only 10 years of evolution… Another source assures that reverse magnetic polarity sunspots located at the less active hemisphere of the Sun during cycle 24 are almost surely the precusors of solar cycle 25…
Here is the latest report from the very realiable Spaceweather site: Spaceweather.com reported new sunspot group 2720 is the first large spot of the next solar cycle, Cycle 25. The magnetic polarity is reversed from the polarity of sunspots in Cycle 24. Whatever is happening 93 million miles away from Earth is going to be quite clear as time goes by. In the meantime adjust your radio hobby operating habits and technologies for monthly sunspots counts of less than 10 for quite some time ahead….
SI amigos you are listening to the middle of the week edition of Dxers Unlimited the radio hobby program covering the more than 93 ways of enjoying our spare time playing with radios, antennas and software. Amateur radio satellites use frequencies that are supposed to be dedicated to that service… Recently, on August 27th, AMSAT Vice President of Operations Drew Glasbrenner, callsign KO4MA, noted:
“Recently there has been a DMR signal QRMing the AO-92 satellite uplink on 435.350 or close by. Hotspots, repeaters, terrestrial simplex (anything not satellite) should not be in 145.8-146.0 or 435-438 by international bandplan.” He requests ground stations using those frequencies to please QSY, move these away from the satellites uplink frequencies. Possible sources of those signal include ease share to DMR, D-star, Fusion, P25 groups and similar terrestrial amateur radio activities.
Again the segments of two meters and seventy centimeters that are to be protected from ground based stations not intended to communicate via satellite are in the 145.8-146.0 segment of two meters and 435-438 Mhz amateur satellite subbands.
It happened 159 years ago…. and scientists are talking about the extraordinary geomagnetic storm that it caused known as the ¨ Carrington Event ¨
159 years ago: planet Earth was hit by a geomagnetic megastorm. On Sept. 2, 1859, a powerful CME rocked Earth’s magnetic field, causing a geomagnetic storm that set fire to Victorian telegraph offices and sparked auroras as far south as Mexico and Cuba. Now known as the “Carrington Event,” that megastorm 159 years ago is a touchstone of modern extreme space weather research. What are the odds it could happen again? The cause of all this was an extraordinary solar flare witnessed the day before by British astronomer Richard Carrington. His sighting on Sept. 1, 1859, marked the discovery of solar flares and foreshadowed a new field of study: space weather. According to a study by the National Academy of Sciences, if a similar “Carrington Event” occurred today, it could cause substantial damage to society’s high-tech infrastructure and require years for complete recovery. Could it happen again? The answer is : Almost certainly. In a paper published just a few months ago, researchers from the University of Birmingham used Extreme Value Theory to estimate the average time between “Carrington-like solar flares.” Their best answer: approximately every 100 years. In other words, we may be overdue for a really big storm.
AM medium wave broadcast band Dxing propagation conditions will see an improvement as we approach the autumn equinox… Look for stations from the Bahamas… there are just three AM stations operating from the Bahamas…
The three are rather easy to log all along the East Coast of North America starting with station, ZNS3, on 810 kiloHertz, from Freeport, Grand Bahama. Described as the Northern Bahamas Service. On 1540 kiloHertz ZNS1 from Freeport Grand Bahama Island runs higher power, while ZNS2 from Nassau, New Providence Island operates on 1240 kiloHertz…
And now amigos, at the end of the show , here is Arnie Coro’s HF propagation update and forecast… Solar activity is at very low levels with daily solar flux figures near the minimum values ever registered since 1947, when solar radio astronomists started to monitor the Sun’s solar flux on the 10,7 centimeters wavelength…..
As all of you are familiar with the close ties between solar flux and HF bands propagation conditions…. it is quite evident that we are going through a period of very poor propagation within the 3 to 30 megaHertz range.
See you all at the weekend edition of Dxers Unlimited and don’t forget to send me your signal reports and comments to inforhc at enet dot cu, and via air mail to Arnie Coro Radio Havana Cuba, Havana , Cuba…..