By Arnie Coro 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.
Item # 1
DXCC COUNTRY/ENTITY REPORT: According to the AR-Cluster
Network for the week of Sunday, 26, August, through Sunday, 2, September, there
were 213 countries active and I guess that the 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) said 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, ionization 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 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 two years to go before it is expected to reach its minimum and cycle 25
to begin. 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 designer 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 considered obsolete but is still in
service with some espeleology teams. The radio uses USB upper sideband
voice operating a 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 cannot 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 precursor of solar
cycle 25.
Here is the latest report from the very reliable
Spaceweather site:
www.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
will going to be quite clear as time goes by.
In the mean-time adjust your radio hobby operating habits
and technologies for monthly sunspots counts of less than 10 for quite some
time ahead.
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 27, AMSAT Vice
President of Operations Drew Glasbrenner, callsign KO4MA, noted: "Recently
there has been a DMR signal QRM'ing 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 band-plan. 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 sub-bands.
It happened 159 years ago…and scientists are talking
about the extraordinary geomagnetic storm that it caused known as the Carrington Event. Exactly 159 years ago, planet Earth was git by 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 mega storm 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 kHz from Freeport, Grand
Bahama.
Described as the Northern Bahamas Service.On 1540 kHz, ZNS'1
from Freeport Grand Bahama Island runs higher power, while ZNS'2 from Nassau,
New Providence Island operates on 1240 kHz.
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 you 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 MHz 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@enet.cu or via air mail to Arnie Coro
Radio Havana Cuba, Havana, Cuba.
(Arnie Coro/R Havana Cuba)