Dxers Unlimited's weekend edition for 25-26 July 2009
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados worldwide ! This is the weekend edition of Dxers Unlimited coming to you after fourteen consecutive days of ZERO OFFICIAL SUNSPOTS.... and why do I use that special term "official sunspots", well , because there is a small group of still in the early stages of developing sunspots that are puzzling solar observers since they appeared at a location and with a magnetic polarity that puts them into the category of a cycle 23 sunspot group....
If this is fully confirmed, then cycle 23 will once again will be a record breaking one, having lasted now more than any other previously fully observed by science solar cycle...
After the fourteen days of zero official sunspots, the HF bands propagation conditions are as bad as you can expect amigos !!! The daytime maximum useable frequency starts climbing very slowly after sunrise and the very weak ionosphere is not capable of supporting the most useful near vertical incidence skywave propagation mode.
Item two: Three Cuban radio amateurs that are avid antenna experimenters have come out with an ultra low cost 2 meters band vertically polarized antenna that is omnidirectional and provides about 5 dB gain over a half wave vertical dipole at the same height. The antenna is made using common household PVC insulated number 16 wire , a short length of PVC white pipe for the coil form and the support is also a three quarters of an inch or an inch
diameter PVC pipe.
Friday evening in our weekly Plaza Radio Club 2 meters band net, we discussed a lot about this antenna and some comparative tests were done, by switching between different antennas and the PVC special, as I have already named it . Results were quite encouraging, and the full instructions to homebrew this easy to build , low cost and highly effective antenna for the FM segment of the 2 meters band are already on line here, so that Cuban radio amateurs can download the computer file with the detailed information on how to build it.
More about the PVC Special later in today's edition of Dxers Unlimited that will continue in a few seconds after a short break for station ID.
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Si amigos , you are listening to Radio Havana Cuba, and now we are testing our 24 hours streaming audio using two Internet feeds... One is full time in Spanish, and the other under the name of Canal 2, provides our listeners with the Radio Havana Cuba languages programs. From Monday to Saturday we broadcast in 8 languages, and during Sunday we add the Esperanto program to the menu. You can try listening to our streaming audio by surfing to our website: , and clicking on one of the two audio buttons ... remember Canal One is all the time in Spanish, and Canal Two is the one with the different language programs .
Item three: The last two VHF contests were quite dissapointing to most of the participants, especially those that have to rely on sporadic E events because there is very little or none local activity on 6 and 2 meters. The number and duration of E skip openings during the two contests was quite dissapointing by all standards, despite the fact that some VHF propagation gurus had advanced that the Sporadic E season would be a record breaking one because it is taking place during a solar minimum period...
Noise, noise, and more white noise coming from the loudspeakers or seen on the computer screens of PSK 31 and other digital modes operators characterized the operating periods of both the ARRL VHF June QSO Party and the CQ Magazine annual July VHF contest...
Item four: My fourteen year old grandson Arnie Coro the fourth is now learning the basic electricity , electronics, radio wave propagation, emergency communications procedures and rules and regulations of the amateur radio service in order to be able to take the exams required to become a radio amateur operator. Arnie the Fourth is to become the third generation of Coro family radio hams ! He is already able to identify the Cuban station's locations by their callsigns, and is learning how to solder , as the first step towards building his first radio receiver.
As expected, Arnie the Fourth has shown a great interest in my digital ham station, because as every child of his age he is really familiar with computers , having started to learn how to operate computers when he was about five years old.
Item five: Got a big stack of e-mail messages waiting to be answered, but don't worry, I don't print them, the stack is inside a computer file in my Puppy Linux lightweight computer, the one that is connected to the digital communications mode station .
Among the most recent requests for information, there is one that shows clearly how computers and radio are interacting more and more for the benefit of our hobby.
As a listener from Sweden says in his e-mail, the PSK 31 narrowband digital communications mode performance is really amazing, considering that it can be implemented even on older computers .
Of course that there are now much more sophisticated digital modes that can actually dig a signal out of the noise and make it totally readable, but those high tech mode do require really fast computers . For every day ham radio operation, there is nothing better at this moment than PSK 31, closely followed by the MFSK 16 and Olivia digital modes.
Just to give you an idea of the tremendous communicating power of PSK 31, I recently ran my digital station here at CO2KK at the exactly one Watt power level, and even under the extremely poor propagation conditions that have prevailed on the 20 meters band, I was able to make several two way contacts with stations in North and South America, and even a very short QSO with a station in Japan !!!
A PSK31 capable ham station is very easy to assemble, as you can use an old computer, install the PUPPY LINUX operating system, and then proceed to install the FLDIGI software that makes possible operating not only on PSK31 , but also on other even more sophisticated digital modes.
There is no need to spend a single cent buying sofware, as both the PUPPY LINUX operating system and the FLDIGI Digital Communications Mode Software Package can be downloaded from several Internet sites absolutely free.
Adding one the nicely written and user friendly LINUX logging program, and a simple HF propagation forecasting program also written for LINUX, you will end up with a very nice DIGITAL STATION, that will be able to communicate even under very poor propagation conditions.
Item six: QSL on the air , QSL on the air, to the many Dxers Unlimited's listeners that have requested more information about the amateur radio satellites that can be accessed using low cost simple ground stations with omnidirectional antennas.
Yes amigos,with a hand held dual band VHF-UHF FM handie talkie, and a homebrew dual Yagi antenna you can communicate using several of the ham radio satellites in orbit. But let me warn you about the fact that those Low Earth Orbit ham satellites are able to support two way contacts during rather short time windows, so in order to be able to use them, you must learn a lot about celestial mechanics, orbits, Keplerian elements etc.
In other words, the radio and its antenna may be quite simple, but been able to make a two way satellite QSO does require the development of a number of skills on the part of the operators. If you do master those skills, then several times every day, you will have short periods , known as time windows, during which the satellites will be available at your location.
The dreams about an amateur radio stationary satellite are now near, as several groups of enthusiastic hams are aiming at finding help from one or several of the telecommunications satellites services provider so that a ham radio satellite may be carried as an additional payload when a new geostationary professional communications bird is launched.
I don't think this is just around the corner, but it is certainly much nearer than say five years ago... Let's hope for those very difficult negotiations to go through succesfully so that in the not too distant future the world's amateur radio population can enjoy communicating by just aiming an antenna to a fixed point in space where the transponder will be waiting for to relay your signals back to Earth.
No, it is not science fiction amigos... there is yet another quite interesting option for a VHF and UHF high above the Earth relay station....
A pilot less aircraft using solar power can hover permanently at an altitude above seventy thousand feet , and it a ham radio repeater is installed aboard that solar plane, the area to be covered by the on board relay station is quite significant...
My point of view is that solar powered electric aircraft are about to reach their technological maturity, they cost much less than satellites and operation can be controlled from a simple ground command station .
They don't need expensive launching pads or sophisticated tracking stations, and in case of a breakdown, replacements can be sent up immediately. By keeping the weight of the ham radio repeater station very low, and using solar power like the aircraft, a very effective airborne relay can be implemented in the near future.
But let me warn you of one big problem to be dealt with by that project.... Frequency assignment ... because the ham radio relay station aboard the stratospheric flying solar aircraft will block its two operating frequencies within a very large area... so a lot of negotiations must take place in order to avoid conflicts among users of the radio frequency spectrum.
Experiments using helium baloons carrying a ham radio repeater on the 70 centimeters band , have proven to be quite succesful, so efforts along that line must continue in order to be ready when the first high flying solar powered planes become available !!!!
And now , at the end of the show, here is Arnie Coro's Dxers Unlimited' s HF plus low band VHF propagation update and forecast.
A very quiet Sun under observation by solar scientists around the world, as they all want to see if the mini spots presumably from cycle 23 wil develop further. Expect very poor HF propagation conditions during your local daytime hours, becoming a little better after sunset.
Chances of sporadic E events are now diminishing as the peak of the summer E skip season is left behind...
Don't forget to send me your comments about this program, signal reports and radio hobby related questions , as well as any suggestions on how to make the nice edition better than this one you have just heard amigos... Send mail to inforhc at enet cu, or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba. |
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