By Arnie Coro radio amateur CO2KK
Hola amigos radioaficionados… now enjoying somewhat better possibilities to communicate using the ionosphere as we continue to transit passing right through the equinox…
It is quite obvious… propagation conditions on the 15 , 12 and 10 meters bands will take a turn for the better as it always happen during the fall season… the higher free electrons concentrations at the height of the F2 layer during the daytime and of the F layer during the evening hours will boost the DX conditions well into the winter season, even while extremely low sunspot numbers are happening.
That was the good news… now ready for the other side of the coin, the bad news: F2, and F layer propagation on those bands will decline thereafter, with only sporadic E events making possible to use the frequency range between 20 and 50 megaHertz during the summer months of 2019 .
The lower bands — 160, 80, 60 and 40 meters — should be good going during the rest of the autumn and winter seasons .
It is expected that the 20 and 17 meters bands will be the mainstays of daylight HF long distance propagation.
In a recent presentation at an international scientific conference, available data suggest that Cycle 24, the current solar cycle, will bottom out in an earlier than previously thought date. That translates into the following information: the year 2019 will see the worst HF propagation conditions since the year 1900. Be advised that radio amateurs may need to lower their expectations on the higher bands, 20, 17, 15, 12 and also 6 meters due to the expected periods of very low solar activity ahead of us..
My perception is that the only logical conclusion we can make with some confidence is that we are headed for several very small solar cycles.” Yes, it is quite clear from various evidence related to the Sun’s polar fields — which appear to be decreasing in strength, A index trends, and cosmic ray data to support his assertion.
Another fact to take into consideration is that “There seems to be a good correlation between how long does a solar minimum lasts and the behavior of the next solar cycle.” “The longer time you spend at solar minimum, the smaller the next cycle is going to be is the logical conclusion.”
Radio amateur operators that, like yours truly, were active since the 1950s and 1960s have experienced short inter-cycles solar minimums of approximately 2 years, until the one between Solar Cycle 23 and Solar Cycle 24, lasted about 4 years producing terrible propagation conditions never before seen . My daily observations of HF propagation conditions since 1957 confirm the above mentioned data.
K9LA Karl Luetzelschwab a well known expert cited historical sunspot cycle data going back centuries — including the “Maunder Minimum” of zero and near-zero sunspots between the years 1645 and 1715 and a later, less-drastic “Dalton Minimum.” He pointed out that over the last 11,000 years, 19 notable grand maximums — including Solar Cycle 19 and the cycles around it — and 27 notable grand minimums were recorded. ” We’re likely to have more of both grand maximums and grand minimums in the future,” he predicted. The current system of numbering sunspot cycles begins with Solar Cycle 1 in the mid-18th century.
“We don’t fully understand the process inside the Sun that makes solar cycles,” Luetzelschwab said. “Thus, you should exercise caution with statements seen in the news.”
I am sure that many of you Dxers Unlimited listeners have heard me many times advancing forecasts about a very small peak of solar activity to happen during cycle 25, while the 2014 cycle 24’s maximum of 114 sunspots count will probably not be happening again in many years to come.. As a preliminary conclusion… we will need larger and more efficient antennas for the lower frequency bands and shift our present operating habits to include more highly sophisticated digital modes like JT65 and FT8, as well as getting better acquainted with amateur radio satellites.. More radio hobby related information, coming up in just a few seconds, after a short break I am Arnie Coro radio amateur CO2KK your host here at the weekend edition of Dxers Unlimited …
This is Radio Havana Cuba, the name of the show is Dxers Unlimited , and here are more radio hobby related items.
Cuban radio amateurs have now passed the FIRST PART of the 2018 Tropical Hurricane Season… Hurricane Michael impacted the western part of the Cuban archipelago, when it was a tropical storm and later when its intensity increased to a Category ONE hurricane, just before it increased its speed and moved across the Gulf of Mexico where it developed fast into a huge Category 4 storm at landfall into the Florida Panhandle.
At the Cuban radio amateur federation website we could see from time to time advisories alerting to protect frequencies on several ham bands that were being used to handle emergency storm traffic in Central America and the Southern United States, areas that did receive the impact of bad weather areas , including tropical storms , and in the case of the USA, one of them did reach the hurricane intensity level…
Si amigos, this is Dxers Unlimited weekend edition and here is now item four: The high cost of commercially built amateur radio equipment with full capabilities places those sets well above what the average entry level ham operator is willing to pay. In the case of nations with low average national income, the development of ham radio is very slow, precisely because of the high cost of the typical HF equipment that fortunately now is not the case with 2 meters band handie talkies that provide quite useful features at prices that are astonishingly low nowadays.
Attempts to reverse that trend, making HF transceivers available at low cost are sprouting all over the world, with efforts coming mainly from radio clubs that count with the cooperation of well experienced amateurs, capable of designing single band low power radios that enter into the low parts count category. Some of them are sold as kits, that is full set of parts with comprehensive step by step assembly and final adjustment procedures in the instruction manuals. Happily, some of those kits have proven to be the road to local growth of activity, and at the same time they have helped to boost the local club’s meetings .
Here in Cuba several radio clubs are involved in the design and construction of single band 40 meters transceivers, based on a well proven design that originated way back in 1982… As a matter of fact, the original Jaguey 82 double side band transceivers were so well built that several of the original prototypes are still on the air, something I learned this past week when receiving a call from a low power station located more than six hundred miles away… He told me that his Jaguey 82 transceiver was now helped by a home brew 50 Watts linear amplifier, built using MOSFET devices that he recycled from computer UPS power supplies…
The original Jaguey 82 rig is simplicity at its maximum, using a direct conversion receiver and a two diodes balanced modulator to generate the double side band signal. The rig is powered using 12 volts DC, that may come from a home brew power supply or from a standard 12 volts car or computer back up battery, making it an ideal rig for handling emergency traffic. Currently an upgraded version of the Jaguey 82 is in the works, adding more audio filtering with a simple two transistors circuit, and now using a MOSFET final amplifier stage, in order to make use of available parts.
Homebrewing your own amateur radio HF bands transceiver is a real possibility that will not only save money but also make you the proud on the air operator of a set that was built with your own hands…
See you all at the middle of the week program next Tuesday and Wednesday UTC days, in the mean time enjoy the certainly better equinoctial propagation conditions now in progress, and expected to continue for at least the next two weeks… Send your signal reports and comments about our programs to inforhc at enet dot cu, or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana , Cuba