Dxers Unlimited’s weekend edition for Sunday July 15 2018
By Arnie Coro
radio amateur CO2KK
Hola amigos radioaficionados all around the world, listening now to the weekend edition of Dxers Unlimited, coming to you via our SIXTY meters Tropical Band and Short Wave transmitters operating on the 49, 41, 31, 25 , 22 , 19 and 16 meter bands and also by the streaming audio via Internet and via the Hispasat 1D geostationary satellite on the transponder 79 vertical polarization… I am your host Arnaldo, Arnie, Coro , radio amateur CO2KK and now here is item one of today’s show….
Current news in the world of short waves …. that are not good at all …The very bad conditions of short wave radio continue due to the very low solar activity … Day after day the solar disk visible from the Earth is completely blank, without a single magnetically active zone, that is without sunspots. On Saturday, July 14, 17 consecutive days had passed without any sunspots being observed. The records of the solar radiation flow in the band of 10.7 meters of wavelengths, continues below 75 units. The ionosphere is not receiving the necessary energy to offer the possibility of long-distance communications via the daytime F2 layer.
More news … follows the extraordinary progress in the use of digital communications mode called FT8 … Although the exchange between stations is very limited to 13 characters per contact, it is possible to communicate when the conditions of radio propagation are extremely bad , because the algorithm for capturing the signals manages to receive when those signals are below the noise. Although it is not as sensitive as the JT65 mode, the exchange is done in much less time, and it is recorded with a numeric reception report …. FT8 is the name of this new communication software that continues in development under the baton of Nobel Prize winner Joseph Taylor K1JT author of a whole family of digital programs for communication
The well-known WINDOM antenna of the first years of amateur radio has a current version, which has received several names, of which the most popular is the CAROLINA WINDOM … whose installation is facilitated because the feed point is located more near to the station because of its asymmetric construction. Several Cuban radio amateurs are successfully using the variants of the Carolina Windom in a version that makes it possible to operate from 80 to 10 meters using a simple tuner or antenna tuner.
And now more about amateur radio
The lack of original factory battery packs for the portable transceivers of the two-meters and seventy-centimeters bands is being solved by Cuban radio amateurs by adapting the rechargeable lithium batteries used in cellular telephones to give power to the popular handie talkies, the stations described in amateur radio licenses as personal mobile sets …. The connection of two or three lithium batteries in series makes it possible to feed those equipment that are so important in emergencies. As an additional advantage is that lithium batteries have much greater capacity to store energy and do not have the harmful memory effect that is observed in nickel cadmium batteries …. The construction of an automatic charger for lithium batteries has become popular from an original Cuban design that has proven to be highly reliable ….
ASK ARNIE… is now on the air… this is the most popular section of Dxers Unlimited according to your e’mail messages, letters and even while having a QSO with my amateur radio station CO2KK. Today’s question came from Argentina, where amigo Raul listens via the Internet streaming audio. He tells me in his email about the excellent results achieved with a one and half meter diameter circular magnetic loop antenna made using the special low loss coaxial cables that go by the trade mark HELIAX…. He tunes the antenna with a homebrew butterfly capacitor and asks how he could use more power fed to the antenna by replacing the butterfly capacitor… Amigo Raul , your best possible option is to try to obtain a vacuum variable capacitor rated at no less than fifteen thousand volts, because you can then feed about one hundred watts full carrier power to the magnetic loop without running the risk of arc overs… I also want to remind you and all other users of magnetic loops for transmitting to keep the antennas at a good distance from your operating position, in order to avoid very intense electromagnetic fields… Using a magnetic loop far from the operating position implies the addition of a remote tuning mechanism that is essential when you want to change frequencies… As a side note, a friend that enjoys using the digital communications modes, tunes his antenna to the popular parking spots for the FT8 mode and he does not need to retune the antenna…. Si amigos magnetic loop antennas deserve much more attention by both short wave listeners and amateur radio operators… when your chances of installing large size external antennas are next to zero.
The World Football Cup acted as a good reason to put on the air many amateur radio stations using special callsigns with the number 18 included in the callsigns as well as the acronymn FIFA for international federation of amateur football… On 10 meters, despite the poor propagation conditions , several of those stations attracted the attention of those devoted fans of the twenty eight megaHertz or 10 meters band… Here are some of the stations heard on 10 meters last Monday AO18FWC, 7X2FIFA, CN18FWC, ER18FIFA, 7X2VFK, PZ5RA, K2K, KH1/KH7Z, K2J, II9FIFA, E70FIFA, HZ18FWC, GI6XX, ZB2JK/P, IS0DCR, 2W1ACM, SV6DBG/B, OE18FIFA, IS0HQJ, EA3FYO.
The other interesting news about low band VHF propagation was that the across the North Atlantic Path between the eastern coast of North America and the British Isles saw a record breaking sporadic E multiple opening that took the maximum usable frequency up to 88 megaHertz… a very rare event by all standards.. On the 21st of June, an also fantastic opening made possible for several Cuban 6 meters band operators to work a number of Japanese stations using CW and Single Side Band…. Due to the lengthy period with a totally blank Sun we may expect more sporadic E layer openings during the second half of July.
And now amigos at the end of the show, be on the lookout for more sporadic E skip openings and somewhat better local nighttime propagation on the HF bands… See you all at the middle of the week edition of Dxers Unlimited, Tuesday and Wednesday UTC days , just after the half hour RHC English newscast… Send your signal reports and comments to inforhc at enet dot cu or via air mail to Arnie Coro, Radio Havana Cuba, Havana, Cuba