By Arnie Coro, CO2KK
Hi amigos radioaficionados ! Welcome to the our weekend edition of Dxers Unlimited, your favorite fully integrated radio hobby program, covering each and every aspect of the wonderful world of radio... from hunting for DX AM broadcast band stations using the most sophisticated crystal sets that are able to provide reception without any external power at all, to sending amateur radio signals on the 3 centimeters or ten gigaHertz band to the Moon and establishing a two way contact with another operator located half way around the world... In between these two extremes there is, of course a very nice aspect of our hobby, short wave listening to international radio broadcasts, the way many of us learned for the first time about this nice hobby, and don´t forget about TV DX, FM broadcast band DX, homebrewing radio receivers and transmitters or building and testing antennas...
All in all, I have a list of 83 different ways you and I enjoy radio... Now here is yet another one...extreme satellite TV Dxing, using very sensitive receivers and relatively large size parabolic antennas to pick broadcast satellites that are located very near the horizon so they are not normally received at that your location...
In other words those TV satellites´s footprints are beyond the location of your receiving station. By using a combination of the extremely sensitive low noise receivers, the big oversize antennas and the eventual help of tropospheric ducting propagation, TV satellite Dxers have picked up signals that have amazed even those who designed the satellite's footprints.. As you may realize amigos, there are still many challenges to deal with, and everytime a radio hobbyst faces one of them, many interesting things happen... Take for example, when many years ago, radio amateurs found out that so called short radio waves could be used for long distance communications, when professional radio engineers and scientists of those times, had proclaimed that the short radio waves should be given to amateurs as they were useful only for short distance communications... Now here is item one of today's Dxers Unlimited's edition...
A question, sent in by several listeners... they all want yours truly to tell them how to continue to deal with the already very long period of solar minimum years....The typical question was : Arnie, you are insisting about the end of the solar cycle, mentioning during the weekend program that we had seen again several days with a spotless Sun... ZERO SUNSPOT COUNT !!! What can be done to face that situation of extremely low solar activity...???
Well amigos, I'll be more than happy to provide you all with some ideas about how to deal with the now already with us extended, and I believe almost record breaking solar minimum....
Si amigos, Dxers Unlimited is a very practical radio hobby show... and all along its existence I have always tried to provide my listeners with the facts that will help them to enjoy the hobby... Dealing with the many consecutive months of very low solar activity is today's program main topic... and I do hope that you can take notes, tape the program or read the script posted to the ODXA e-mail list, the Ontario DX Association YAHOO mail list that so succesfully has provided its members with up to date radio hobby information.
.. SOLAR MINIMUM.... yes, you have heard that dreadful phrase more and more often as we approached the years 2006 and 2007, when scientists had forecasted a period of extremely low solar activity as solar cycle 23 was reaching its end... But, first things first... don't think that one cycle comes abruptly to an end, like flipping a switch off and the next one starting at the flip of another start up switch...
Solar cycle 23 has winded down now for a very extended period, and now it is predicted that soon we will be hopefully seeing more sunspots of cycle 24... as the two cycles overlap for a period lasting many months... Cycle 23, the present one, was a higher than average one, that showed to peaks of activity,but now scientists are forecasting that cycle 24 will be no match to the preceding two cycles, but that's something yet to be seen...
Now here is the answer to today's question sent to our ASK ARNIE section of Dxers Unlimited by many listeners from all around the world... Here is a STRATEGY TO DEAL WITH SOLAR EXTENDED MINIMUM !!!!
First things first.... monitor the Sun's activity more precisely than ever, as during the solar minimum there are certain periods of higher activity that will provide you with nice Dx opportunities on the higher frequency bands..As a matter of fact, we have just gone trough of those "active periods" during solar minimum, and even a solar flare erupted from a sunspot region that reached a complex magnetic configuration. So, rule number one of the game: MONITOR THE SUN on a daily basis and keep a record of the daily number of sunspots, the solar flux and information about coronal holes...
Your solar records will help you plan in advance for any upcoming contest, as the Carrington solar rotation, the 27 days and forty one minutes that the Sun takes to rotate at its Equator will help you to forecast periods of lower or higher solar activity...
NOW, second rule of the game: MONITOR the HF bands using the higher frequencies first approach, also known among experts as the downward sweep..A receiver with a slow motion dial drive is ideal for this purpose, and it is second only to a HF spectrum analyzer connected to a wideband antenna system, equipment that is totally out of the question for normal people like you and I...
Doing the downward spectrum sweep with a receiver connected to a 14 meters long Tilted Terminated Folded Dipole wideband omnidirectional antenna, will give you information about the highest frequency that is propagating at anytime... For example, Monday late evening local time here in Havana, it was actually about two o'clock in the morning, I ran a downward sweep starting at 15 megaHertz, and met with the first signals on the 25 meters international broadcast band, around 11.9 megaHertz...It was obvious that the maximum useable frequency curve was way down, something that led me to keep tuning down in frequency until I reached the 40 meters amateur band, where many signals from Europe, Asia and the Pacific where present...
So, if you have not yet built your wideband TTFD short antenna for the frequency range between 7 and 35 megaHertz, it's about time to start collecting the materials and homebrewing one, as this antenna will be your number one aid during solar minimum years...More about how to deal with SOLAR MINIMUM as Dxers Unlimited's weekend week edition continues ..
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Si amigos, an unusually extended solar minimum is here, but that doesn't mean that you have to shut down your radios and wait until the sunspots are back... Here is now Arnie Coro's number three tip for dealing with the solar minimum years...
Build yourself a large sized magnetic loop antenna, capable of operating from 1.5 to 5 megaHertz.... If used for receive only applications, the magnetic loop may be tuned using a conventional receiving type variable capacitor... Why do I recommend the magnetic loop for the 1.5 to 5 megaHertz frequency range... well, because a lot of DX activity is certainly happening there during these long months when the sunspot count is extremely low...
A good friend of mine, with whom I discussed the strategy for the solar minimum years recently, said that he was getting ready to homebrew a five meters by five meters magnetic loop, using the fiberglass spreaders that are made for building cubical quad antennas for the amateur bands... He has already made a two by two meters magnetic loop, using RG-213 coaxial cable for the antenna element with very good results...
And he is looking forward on how to deal with the much heavier five by five meters version of the magnetic loop that he affirms will be able to tune down to the low end of the AM broadcast band, where Dx stations from Europe may be frequently picked up in the Americas during the solar minimum years. Now rule number four: And this one applies only to amateur radio operators..,rule number four calls for calling CQ DX as much as possible, yes,calling CQ DX everytime you have an opportunity...
You will be pleasantly surprised to see that calling CQ DX at three o'clock in the morning local time on an otherwise apparently dead band,like 30 meters may seem to be at that time, may bring in DX from halfway around the world, exactly as it happened to me on the 30 meters or 10.1 megaHertz amateur band at exactly that time from Monday to Tuesday my local time, that was at 0700 UTC.
Last but not least, if you are the happy owner of a lot of real state where to install long wire antennas, by all means try them ! A Beverage long wire terminated antenna three,four or five city blocks long, mounted on typical fence posts at about 2 meters above ground will bring incredible DX from the direction to where the termination of the antenna is looking at... Some low frequency Dxers, the guys that enjoy most the solar minimum years have installed not one, but several long wire terminated Beverage antennas in preparation for the very low solar activity that is expected to continue for the next several months...
Well amigos, I hope that this information on how to deal with the solar minimum years will be useful to you all, both newcomers and experts... the newcomers to the hobby will be remembering their first quiet Sun, and the oldtimers will recall really lengthy periods of the quiet Sun as the one that happened during 1965...
AH... and before I forget... running a little higher power on your amateur radio transmitting equipment will also help to deal with the solar minimum.. Boosting the power from 10 Watts to 100 Watts, that is by 10 decibels will improve your chances of having nice two way contacts under a very weak ionosphere ...
If you have any further questions or doubts about how to deal with the low sunspot we are all watching now, send me an e-mail to inforhc@enet.cu
Well amigos, I hope that the information provided during today's Dxers Unlimited will be useful for you all... now , here is our exclusive and not copyrighted HF plus low band VHF propagation update and forecast...
Sporadic E openings soon to be starting on a day to day basis.. You should be able to pick up many low band TV channels stations using simple antennas like my 2 meters long VHF TTFD omnidirectional antenna...
Radio amateurs will also enjoy the first two way contacts of the sporadic E season really soon, especially on the 10 meters and 6 meters bands, but signs of very short skip will also show up during sporadic E openings on the 12, 17 , 15 and 20 meters amateur bands, remember that calling CQ DX when there are signs of an opening is very important, so that other amateurs will be able to know that the bands are open. Solar flux is still at very low levels, as well as the zero sunspots condition….
Latest solar flux figure was around 68 units, and the optical sunspot count was ZERO... See you all at the midweek edition of Dxers Unlimited next Tuesday and Wednesday UTC days amigos, and don't forget to set aside a little time to send me feedback about today's program to inforhc at enet dot.cu , again inforhc@enet.cu, so that the next edition of the program may be , thanks to your help, a bit better than this one !!!
(Source: Arnie Coro/Radio Havana Cuba)