Dxers Unlimited weekend edition for Sunday 12 August 2018
By Arnie Coro
radio amateur CO2KK
Hola amigos radioaficionados, I am Arnie Coro , radio amateur CO2KK bringing to you the week end edition of Dxers Unlimited, and here is our first news item:
A press realease from the American Radio Relay League reports the passing away of William A. “Bill” Tynan, W3XO, of Kerrville, Texas, who died on August 7, following a lengthy illness. Bill played a vital role in the development of amateur satellite communications worldwide.
A past AMSAT President and the editor of the QST column “The World Above 50 MHz” from 1975 until 1992, Tynan was 91.
In 1969, his eager curiosity for VHF and other modes led him to attend the first meeting of what would become AMSAT. In his later years, Tynan served as AMSAT’s OSCAR Number Administrator, the individual who confers alphanumeric designators on qualifying ham radio satellites. He stepped down from that volunteer role in July 2018 after 2 decades.
And talking about amateur satellites, the long awaited first stationary satellite is hopefully to become a reality maybe by next year… This geosynchronous bird will cover about one third of planet Earth’s surface with its signal, but it will require special equipment and operator’s skills to make use of it.
This is Radio Havana Cuba, the name of the show is Dxers Unlimited on the air twice weekly to provide information about our wonderful radio hobby…. yours and mine… Here is our next news item…
Digital Terrestrial Television Dxing is becoming widespread here in Cuba thanks to the use of high gain receiving antennas that can be built at home with hand tools. The high gain brings in distant transmitting stations that are not normally seen in far away locations. I have seen very well built long Yagi type antennas with estimated gain figures of about sixteen decibels over a half wave dipole , achieved by stacking four 10 elements antennas using an open wire line stacking harness. At the feedpoint the antennas are connected to low loss coaxial cable, and at some locations a mast-top preamplifier is included in the set up. TV Dxing the low band channels is no longer popular because by picking up a single digital transmitting station on the VHF High Band or the UHF band one can receive eight standard definition TV stations and 9 stereo audio radio stations with excellent quality. As the low band , channel 2 to 6 TV stations in North America and Mexico migrate to digital systems, the possibility of picking up signals via sporadic E layer clouds of ionization is vanishing .
Spaceweather.com reported on August 8, 2018 that “Solar minimum conditions are in effect. The sun has been without sunspots for 39 of the past 42 days. To find a similar stretch of blank suns, you have to go back to 2009 when the sun was experiencing the deepest solar minimum in a century. Solar minimum has returned, bringing extra cosmic rays, long-lasting holes in the sun’s atmosphere, and strangely pink auroras.”
For the third week in a row, we report an average daily sunspot number of 1.6. Why? It seems that in the past three reporting periods there was only one day with any sunspots and each time that daily sunspot number was 11.
Average daily solar flux rose slightly from 68 to 69.7, while average daily planetary A index rose from 5 to 5.7, and average mid-latitude A index changed from 5.1 to 6.9.
And now more bad news related to the solar minimum… Predicted solar flux is 69 on August 11 to 22, 70 on August 23 to 31, 69 on September 1 to 18, and 70 on September 19 to 23. There is no doubt amigos…. solar cycle 24 is showing an anticipated minimum… making it shorter than usual
QSL ON THE AIR …. to listeners in western Canada and the west coast of the USA reporting very good reception on our 6100 kiloHertz frequency that is using our 315 degrees azimuth high gain , four by four curtain array…. QSL on the air to listeners in Scandinavia reporting reception of our 6000 kiloHertz frequency reaching you at the extreme end of the main lobe of the two by four set of dipoles antenna beaming zero ten degrees azimuth, but still providing useful signals up to 45 degrees each side of the center of the beam … Good reports from Sweden, Norway and Denmark –
This is the weekend edition of your favorite listener oriented and technically minded radio hobby program, with yours truly Arnie Coro radio amateur CO2KK as your host. Here is now our next topic…
Several Cuban radio amateurs that operate on the short wave ham bands from 40 to 10 meters are achieving good results with a very simple wire antenna that has the advantage over a dipole that it is fed at one end using a balanced to unbalanced broadband transformer… There are ongoing discussions about the impedance transformation ratio required for this end fed antenna, and all I can say is that my tests using an 11 meters long wire that is installed horizontally show that using a standard factory built four to one balun and 50 or 75 ohm coaxial cable makes possible to operate on the 40, 30, 20, 17, 15, 12 and 10 meter bands using my wide range PI network antenna tuner. Because the length of the coaxial cable downlead is less than 15 meters, losses due to high standing wave ratio are minimal. The antenna behaves as an omnidirectional system on 40, 30 and 20 meters, but starts to show up some directivity above the 20 meters band… I use standard home made insulators cut from sections of RG17 heavy coaxial cable that are prepared by drilling holes at each end of the fifteen centimeters long sections of RG17 center insulation, by removing the braid from the cable… Due to the excellent VHF and UHF behavior of the RG17 cable , my homebrew insulators are second to none, and cost much less. From a short end of RG17 removed by a local FM broadcast station , I have made so far about thirty such insulators for my wire antennas, and as always give to local radio amateurs that are now starting to operate on the HF bands.
Si amigos, yes my friends, oui mes amis, this is the weekend edition of Dxers Unlimited , now ASK ARNIE the second most popular section of this show..
Today answering a question sent by listener Rafael from Barcelona, Spain who monitors Radio Havana Cuba via our Internet Streaming Audio… Rafael lives in an apartment building and he can install a wire antenna from the back of his home to a lamp post at the parking lot… He uses black teflon insulated wire and so far no one has complained, but he needs to know the optimum length of the wire for him to be able to operate on the 80 meters and 40 meters band. Amigo Rafael you will need to install an end fed wire antenna of 19 meters overall length… it can slope down at an angle of maybe 30 degrees and will require a balun at the feed point… My advice is to try first with a four to one balun using a short length of 50 ohms or 75 ohms coaxial cable to connect to your antenna tuner, and then test the antenna on 3,8 megaHertz, that is near the DX window for SSB stations… Run a second test on 7,1 megaHertz for 40 meters and see if it is possible to achieve a one to one Standing Wave Ratio . Above 40 meters the 19 meters long end fed antenna will become more and more directional , something you will soon find out, but on 80 and 40 meters the antenna will show practically omnidirectional radiation …
And now again more news about solar cycle 24, now on the track to reach absolute solar minimum much earlier than was expected by a panel of experts four years ago… The month of July solar activity report brought the data showing a monthly average international sunspot number ISN of a mind boggling low of less than two, actually the July monthly ISN was 1,6, yes you heard it right , just one decimal six a sure indication that solar minimum is now in progress…
See you all at the middle of the week Dxers Unlimited edition next Tuesday and Wednesday UTC days amigos…