|
|
|
Dxers Unlimited's week end edition for Sunday June 16 2013
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados !!! welcome to Radio Havana Cuba's twice weekly radio hobby program... I am your host Arnie Coro, and here is item one of today's program. In 2007 we went through what solar scientists described as the
Year of the Quiet Sun, when solar cycle number 23 was expected to come to an end, something that did not happen, because the period of extremely low solar activity stretched all along 2007 and continued until the end of 2008.... some scientists had warned us that that the Sun was in an unusually low activity ,and they were quite right...
Now here is ASK ARNIE, the section of this show that continues to be LA NUMERO UNO,number one , the most popular section of the program , but, as expected it is closely followed by the HF plus low band VHF propagation forecast that goes at the end of the show,and if you guessed that the number three most popular section of the program was the one devoted to the technical topics , you were right, but TT , the Technical Topics came out tied with the antennas topics section...
Here are some of the requests that I have received here recently, from people like you that listen regularly to the program, as well as from those who have recently heard Dxers Unlimited for the first time...
Arnie, please include more amateur radio hobby topics for beginners , now that in practically the whole world, passing the amateur radio license test has been made easier by the removal of the CW Morse Code requirement. Another request mentioned the interest of including more operating tips, like special propagation reports when amateur radio contests are approaching.
Amigos, I want to thank you all very much for sending those valuable opinions, and be assured that Dxers Unlimited will continue to be your favorite radio hobby program , dealing with the more than 90 different ways you and I enjoy this wonderful way of spending our spare time in a most fascinating and relaxing way...That is, of course playing with our radios !!!
Stay tuned to Dxers Unlimited coming to you from sunny La Habana that will continue after a a short break, I am Arnie Coro in Havana, back with you in a few seconds.
..... short break, music transition
Yes amigos ...you are listening to Radio Havana Cuba, the name of this show is Dxers Unlimited, and when it started some twenty years ago , it was originally supposed to be devoted only to short wave listening when it started,, but now a quarter of a century later, you can learn here about such interesting aspects of the radio hobby as home brewing ultra simple radios and accepting the challenge of picking up long distance stations with them, or installing a magnetic loop antenna to make possible operating your amateur station from a high rise apartment building where no external antennas are allowed, you can also enjoy listening to the technical topics section contents, guiding you trough sometimes quite controversial technical stuff, like the so called Crossed Field Antenna , or CFA, properly described as one of the greatest scams ever in antenna technology...
No amigos the CFA antenna doesn't work at all, and as a matter of fact, at least two of those antennas sold to broadcast stations have been the subject of great controversy that ended up in court. The most famous one ended in a lawsuit by a station located in the Isle of Man, and that operates in the so called Long Wave AM broadcast band... the station was erroneously led to believe that a CFA antenna would be better than any other “classic” design ...Because it will use a very low height vertical radiator.
Now, let me try to update at least part the backlog of questions sent to ASK ARNIE ...
Here is the answer to one of the questions received, sent by three listeners, one in Canada, the other in Sweden, and the other in Germany, the three say in their e-mail messages sent to inforhc at enet dot cu, that they want to know more about digital radio broadcasting technology and how I see its future... So , here we go... First of all digital radio broadcasting as we know it today is only heard regularly by a very small number of radio's worldwide audience... That's a fact that no one can deny... Second: The existence of several different digital broadcast technical standards is making a very negative impact in the expansion of this new technology, and in the third place is the fact that radio receivers for picking up digital broadcasts are still rather expensive, and in many instances hard to find or actually non existing in many countries.
Digital broadcast technologies for local ground wave transmissions on both the AM long wave and medium wave bands, and also on the VHF FM bands, when received at a fixed site seem to work quite well now, and the audio quality that can be implemented is as good as one may want.
But there are quite a few problems still to be solved when , for example, digital radio signals are received in areas where , in the case of AM medium wave broadcast band stations, the ground wave and the sky wave combine with each other randomly to produce a very annoying signal fading. Digital radio technology in my opinion hasn't solved this problem yet, so when you are located inside that critical reception area or fading ring, your radio will suddenly go silent for certain short periods, a very annoying problem to say the least.
Digital radio broadcasts on the FM band suffer from a similar problem due to the so called multipath propagation , so when you are travelling on a vehicle and listening to a digital station, you are likely to experience the same annoying total drop outs in service.
Yes, of course, there are ways to go around this problem, but they will require a totally different technology that will include a high degree of redundancy into the digital streams, and a sophisticated receiver that will actually do a lot o signal processing before sending the audio to the loudspeakers or headphones !!!
Now here is a mid term HF propagation forecast, looking forward to the next year and beyond. Be prepared for very poor HF propagation conditions that will keep the bands above fifteen megahertz totally dead ... when the very shallow peak of solar cycle 24 comes to an end by mid 2014 , if forecasters are on target.
As requested by many listeners, more information about a radio noise related topic follows... Those sending the request wanted to know if it is true that the new high intensity light emitting diodes lamps are a good replacement for the noisy energy saving fluorescent electronic lamps of CFL's that generate so much radio frequency noise.
Well amigos, so far the high intensity light emitting diode lamps that t I have learned about seem to require the use of a certain number of those devices in order to achieve enough light output, as technology has not yet provided a really large size light emitting diode , large enough to produce a light output similar to even a small 10 Watt incandescent bulb... But let me say that I am still in doubt with the new high intensity light emitting diode replacement lamps, because I haven't had the opportunity of seeing how do they provide the low voltage required to operate the LEDs... If the low voltage is obtained by means of a simple dropping resistor and rectifier diodes combination, then the lamps will not generate radio frequency noise, but if some type of switched mode power supply system is used, then the power supply of the LED lamps will cause interference to radio reception, as is the case with the present day energy savers fluorescent lamps that make radio reception so difficult wherever they are in use.
Note: The HF propagation update and forecast is not included here, because it is recorded at the nearest possible time to the actual first on the air broadcast of Dxers Unlimited.
- Read more...
|
|
|
|
|
Radio Havana Cuba
Dxers Unlimited's middle of the week edition for Tuesday 11 June 2013
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados all around the world... I am Arnie Coro, radio amateur CO2KK, your host here at this program devoted to our wonderful hobby... yours and mine.... RADIO... Yes, This is Radio Havana Cuba's long standing contribution to the promotion and development of this very enjoyable way of spending at least part of our spare time... playing with our radios ... By the way, the weekend VHF contest here in the Americas was a really dissapointing one, because the much expected Sporadic E layer band openings did happen, but with much less frequency along the time of the contest, and when the 6 meters band did open, the openings did not last long. On two meters the prevalent mode for most of the participants was tropospheric propagation, as really few stations in the world are equipped to work using the Moon as a passive reflector, via the so called EME or Earth Moon Earth signals path ... So now VHF bands radio amateur operators are waiting for the second big summer contest to take place in July, and keeping the hope that the Sporadic E layer clouds will appear soon . Now let me tell you that even under poor propagation, you can enjoy our hobby by setting up a portable ham station at a park and show people how you are able to talk to other radio amateurs using low earth orbit satellites... The LEO or Low Earth Orbit satellites provide very short time windows , but they are almost totally independent of ionospheric propagation conditions .
By the way, Hector Martinez CO6CBF, Cuba's top ham satellites expert graduated from the University of Cienfuegos engineering school with a magna cum laude decree in information sciences engineering, and that is very good news to ham satellite operators because from now on Tico, as we call him by that nick name, will have more time to experiment with his unique amateur satellite communications station. Congratulations to this young man that is an excellent example of the new generation of radio amateurs that have proven to be capable of incorporating the latest technological advances to the hobby .
Last year Tico did some really interesting demonstrations of satellite communications at a small town's central park. He was able to contact 21 stations on three satellite passes and a lot of contacts were done on the HF bands and also on 2 meters band local repeaters. A lot of people came to the presentation and some, as expected, then asked about how to start their first steps into the amateur radio world.
Tico CO6CBF told me that the most exciting part for the audience was when they heard the contact between NA1SS operating from the International Space Station and K3CUJ from the National Electronics Museum, Linthicum, Maryland.
It was a great experience for everyone at the Aguada de Pasajeros central park that provided an excellent promotion to the amateur radio hobby. And as I said at the start of the show, all this can be done without having to worry about HF bands propagation conditions.
Equipment used for this type of portable satellite operation is what is regularly used when operating portable. A mobile 2m FM radio with a homebrew 70cm/2m down converter inside, The classic 2m Kenwood TK-270 Handie Talkie for transmitting, a 12V 7AH battery into a backpack to power up everything , plus digital MP3 recorder to log the contacts. One holds the HT in one hand and the homebrew Arrow Antenna dual band YAGI with a homebrew preamplifier with the other hand.
Yes amigos, that was a really nice way to promote our hobby... which has also received attention during the past several days from our national mass media, by highlighting the role of amateur radio operators providing alternative emergency communications as very heavy rainfall poured for about six days over the extreme western part of Cuba.
Item two: An old amateur radio saying goes like this: if you can not hear them you can not work them... that meaning that if your antenna and receiver are not good enough, you may own a powerful transmitter, but would not be able to make two way contacts.
Two days ago I began wiring a new two transistors regenerative receiver designed by Michael Rainey, radio amateur AA1TJ, who happens to be a real wizard in achieving fantastic results with minimum parts count radios. This particular design uses a field effect transistor as the regenerative detector and a single high gain audio NPN transistor that feeds a pair of earphones by means of a classic output transformer. The receiver module was built using the classic point ot point wiring technique on top of a small piece of circuit board that I had at hand.
So simple as it looks will sort of make people believe that it is not capable of good performance on the 40 meters band... But actual practical results show that Michael's design is very sensitive and also very selective when you tweak the regeneration control to achieve the best possible performance.It is a hands on project ... I can pick up very weak single side band voice stations, and even weaker CW signals ... One alert I received from AA1TJ was to keep the antenna coupling to the gate tuned circuit to absolutely minimum values, so that the high gain detector would not overload. Michael uses two different values of coupling capacitors, one for daytime listening and the other for night time reception of 40 meters that requires a lower value of coupling capacitor.
By the way, the 40 meters band is the most popular ham HF band here in Cuba...because it provides excellent daytime communications all through the Cuban archipelago.
This radio's simplicity is ideal because it can be built with the typical electronic components that we Cuban hams recycle from many sources, like for example, the compact fluorescent ligh tbulbs, computer motherboards and TV sets or computer monitors, that have proven to be a treasure chest of good quality parts, that in most cases are in a like new condition. Once we found out that the CFL ligh tbulbs failures are concentrated on two or three parts, it was proven to be possible recycling silicon high voltage diodes, polyester dielectric capacitors , resistors and electrolytics... The power transistors that are used to generate the high frequency currents do fail, but in many instances just one of the two is the cause of the ligh tbulb failing. .
The 40 meters band regenerative receiver tuned circuit was built using home brew coils wound on small stubs of PVC plastic pipe. For those of you that may be skeptical about the performance of AA1TJ's two active devices regenerative receiver design, let me explain that comparative tests with a professional communications receiver have demonstrated that the little homebrew radio is almost as sensitive as the expensive commercial unit... During average day to day operating conditions on the 40 meters band, our set works quite well, and shows that even when using a simple design, the performance will surprise even the most skeptical radio amateurs that have worked always using very well designed and well built professional transceivers. Stay tuned for more radio hobby related information, coming to you from sunny Havana, where the summer has just ended on the last day of August
I am Arnie Coro radio amateur CO2KK, back in a few seconds amigos !!
....................
This is Radio Havana Cuba, the name of this program is Dxers Unlimited, that meaning that it a radio hobby oriented show, designed to promote and encourage listeners to enjoy the many different aspects of this wonderful way of spending our spare time ... that is, playing with our radios in one or more of the 90 different ways that it can be done.
Here is now our next item of this show....One of the favorite ones ...the ANTENNA TOPICS section of Dxers Unlimited will today add still some more information about the 7 meters long inductively loaded sloping antenna, that can be set up using a single mast. Some users of this antenna have it installed as a standby or second option system, but they have discovered, especially when operating on the 20, 17 ,15, 12 and 10 meters bands, that the 7 meters long wonder sloping antenna sometimes matches or even provides a better signal than a classic two elements YAGI.
And now amigos as always at the end of the program here is Arnie Coro's HF plus low band VHF propagation update and forecast... Expect more Sporadic E opening to happen all along the week .Solar activity now back to the below 100 solar flux units mark.... and that will show up in poor to very poor propagation conditions on frequencies above 20 megahertz, Please send your signal report and comments about this and other Radio Havana Cuba programs to inforhc at enet dot cu, again inforhc at enet dot cu, and VIA AIR MAIL send a postcard or letter to Arnie Coro, Radio Havana Cuba, Havana , Cuba
Read more...
|
|
|
|
|
Radio Havana Cuba
Dxers Unlimited's weekend edition for Sunday June 9 2013
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados all around the world and orbiting Planet Earth ....welcome to the weekend program, YES, this is our weekend show now on the air and also available via the world wide web site
www.radiohc.cu.. just click on top of the channel 2 loudspeaker icon.
I am your host Arnie Coro, radio amateur CO2KK, and here is now item one of today's program: The upswing in solar activity that started a few months ago,as solar cycle 24 moves towards its expected peak , has revived the interest in amateur radio two way long distance contacts.
As a matter of fact, monitoring the 17, 15, 12 and 10 meters band you will be able to pick up some very exotic callsigns , some of them coming from succesful DX expeditions that have travelled to remote and unsual locations to activate rarely heard DX entities in order to take part in ham radio contests .
As solar cycle 24 continues to move towards its maximum with ups and downs, but with a clear tendency UP, the monthly solar flux averages continue to move to higher values, and already the month of May average sunspot number passed the 75 mark, that is why the ionosphere receives much more solar radiation that splits atoms from their electrons , providing the required higher free electron concentrations per cubic millimeter needed for higher frequency radio signals to bounce back to Earth, instead of continuing travelling to outer space.
No doubt that cycle 24 is the second solar cycle that takes place after large scale connectivity to the Internet became available, so now we are seeing more than ever before the use of the world wide web to enhance amateur radio activities.
For example, several websites provide instant feedback about stations that go on the air from rare DX entities, and other sites act as robot monitors with receivers that will tell visitors who is on the air calling CQ on the ham bands at any given time ...
Item two: The ever popular technical topics section receives many e-mail requests from listeners of Dxers Unlimited asking for specific solutions to problems that
the have with their radios and accesories. This is now one recent example of a request about what should be considered the right moment to perform a major overhaul to an amateur radio transceiver that was designed to operate on the HF or short wave ham bands.
This is certainly a difficult question because it is dependent on many different factors... among them the type of technologies used to build the transceiver, and
the actual age of the rig. Then you must add a very important element, and that is no other than the existence or non existence of the required professional quality test instruments that are essential in order to carry out a complete alignment of the transceiver and the know how by the person who is going to attempt the major overhaul.
My opinion about those major overhaul attempts is that only in very few cases all the required conditions to carry them on will be available... So what I recommend , in the case of more than 20 years old amateur radio transceivers is to subscribe to one of the Internet mailing lists that deal with users information about a specific rig, like for example the YAESU family of hybrid Fox Tango or FT transceivers or the Kenwood hybrids like the TS520 and TS820....By downloading the messages posted to those lists you will learn a lot about the weak points that do need to be dealt with, and also about really valuable and practical to implement modifications...
Some of those modifications or MODS as they are also known on the web, will certainly improve the performance and reliability of those nice hybrid and early solid state amateur radio transceivers. Among the things that you will find out from the treasure chest of users experiences is the fact that after more than 15 or 20 years of use, replacing the high voltage electrolytic filter capacitors with brand new ones , fully tested with an ESR or equivalent series resistance meter, is an excellent number one step .
In general, electrolytic capacitors as well as tantalum dielectric capacitors do loose their properties with age, and they are the main cause of problems and breakdowns that increase with time on those older ham transceivers...
Stay tuned for more radio hobby related information, out of our now updated list of 90 different ways of enjoying this wonderful hobby , yours and mine. I am Arnie Coro radio amateur CO2KK in Havana.
......................................
You are listening to Radio Havana Cuba, the name of the show is Dxers Unlimited, and you can always contact me directly via inforhc at enet dot cu, again inforhc at enet dot cu ...You can send your signal reports, QSL requests, comments about this and other RHC programs and your radio hobby related questions that will be answered as soon as possible directly to your e-mail address and also on the air... Like the example that follows...
Listener Costas from Athens , Greece , is among those who listens to Dxers Unlimited via the world wide web , and he tells me that now he is also able to pick up Radio Havana Cuba using his new shortwave radio, so he wants to know it this was made possible by the increase in solar activity or by our station sending its signals towards Europe. Well amigo Costas, you are absolutely right twice, because both our 6000 kiloHertz and our 6060 kiloHertz frequencies are broadcast to the eastern area of North America, from northern Florida to the Canadian Maritime provinces...
But, the fact is that the two curtain antenna arrays do radiate also some power towards western Europe. If those two frequencies are clear in Europe , then you will be able to pick up Radio Havana Cuba on short wave... Also the recent increase in solar activity is really helping too. But if there is co-channel or strong adjancent channel interference, then it would be impossible to pick up our station in western Europe. Again our target area on 6000 and 6060 is the Atlantic coast of North America, also known by geographers as the Eastern North America seaboard ....
So I hope that those two frequencies will be free of interference in western Europe during the early morning hours local time there ,so that you may enjoy listening to our short wave signals ....
Item four: No doubt about the fact that radio amateurs of the new generation are much more familiar with computers and new information and communications technologies in general than old timers... This is why I am seeing so much activity on the HF or short wave ham bands using digital communications modes....
For example T43C, the contest station that took part in this weekend American Radio Relay League VHF Contest added PSK31, a digital communications mode to voice and radiotelegraphy that they had used in previous contests. The keyboard to keyboard instant modes of which the one known as PSK31 continues to be the favorite among digital operators...
But newer and recently developed digital modes are making possible to communicate under very marginal propagation conditions , making possible to reach the Moon and back with relatively low power on the two meters band thanks to computer software that is able to extract the signals from noise in what can best be described as amazing recovery of what is been sent..
And now amigos, as always at the end of Dxers Unlimited, here is Arnie Coro's exclusive and not copyrighted... propagation update and forecast... Solar flux is hovering at 110 units, and the geomagnetic disturbance indicator, the A index is returning to near normal values after an unexpected event sent the A index to high values on Friday and Saturday... Propagation on the HF bands should go back to the normal summer conditions during the rest of the week, but beware of possible solar flares Also be ready for enjoying many sporadic E layer DX contacts on the 10 and 6 meters bands
Send me your signal reports and comments about today's program so that the next edition will benefit from your feedback amigos... Send e-mail to inforhc at enet dot cu, and VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana. Cuba
Read more...
|
|
|
|
Radio Havana Cuba
Dxers Unlimited's middle of the week edition for Tuesday June 4 and Wednesday June 5 UTC days
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados enjoying this wonderful hobby in so many different ways... from getting ready for an upcoming ham radio contest , to carefully soldering miniature parts into a circuit board where a new radio is almost ready to start picking up stations... I am Arnie Coro, radio amateur CO2KK, and like you my passion for this hobby has brought some really rewarding moments in my life...
Take for example, when the first ever Earth Moon Earth amateur radio contact made from Cuba, something that was achieved using home built antennas and a low power amplifier by EME standards... Yes amigos, many of you keep a close watch on the Sun, and have learned a lot about how our nearest star behaves... plus how solar activity influences radio waves propagation. There are now more than 90 ways that meet the criteria of radio hobby variations... from listening to the AM broadcast band late in the evening using a pocket sized portable radio, to aiming a hand held dual band antenna at an approaching Low Earth Orbit satellite that has an amateur radio transponder on board...
I would very much appreciate comments about your personal radio hobby most rewarding experiences, so that we can share them with other Dxers Unlimited listeners around the world. Now item two of today's program coming to you from very wet and still rainy La Habana... as we are entering into the tropical hurricane season , that starts on the first day of June and that this year is expected to be a very active one indeed.
That is why radio amateur operators from the Caribbean area, including the smaller islands of the Antilles, as well as the three larger one, Puerto Rico, the Hispaniola that is the home of Haiti and the Dominican Republic as well as Cuba are getting their equipment ready to provide emergency communications under even the most challenging circumstances...
When wired and cellphone systems fail due to extreme weather, when there is no Internet available , when electricity distribution systems colapse, a small , portable amateur radio station using a car battery as its only power source has proven to be a lifesaver for many people when a powerful hurricane has struck with its combined destructive power of wind gusts and heavy rainfall.
More about how to get prepared for handling emergency communications as a storm approaches , then when it is actually hovering over you, and finally when it is all over and local authorities are left without any other means of communication than the amateur radio volunteers.
Stay tuned for more radio hobby information and updates coming up in a few seconds , here at Radio Havana Cuba... I am your host Arnie Coro ...
.........................
Si amigos, sure, you can pick up our programs by visiting www.radiohc.cu and selecting the Channel 2 radio button at our homepage... We stream the audio at a low bit rate in order to make possible reception by those cybernauts that have a slow Internet connection...
Now here is item three here at the middle of the week edition of Dxers Unlimited.
The 2 meters amateur band is by far the most popular amateur radio frequency segment in use worldwide. The price and quality of portable hand held FM 2 meters band transceivers are now more user friendly than ever... offering features that a few years ago could only be available from extremely expensive equipment. As a matter of fact the ubiquos HAND HELD 2 meters band FM battery operated transceiver has proven to be a life saving device under extreme emergencies .
By replacing the original handie talkie antenna, ham operators are able to extend the range of that type of portable station , a very useful feature when the local and semi local 2 meters band repeaters go out of service because of the severe weather conditions.
The other option to provide longer range emergency communications makes use of the Earth's ionosphere, by sending signals up to heights where the number of free electrons is high enough to send the radio waves back to Earth in an area that sorrounds the transmitting station in a circle that may be up to 500 miles wide. The so called Near Vertical Incidence Skywave propagation mode does not require repeaters to provide excellent links at distances that far exceed the coverage of hand held or mobile 2 meters FM radios.
A portable ham radio station capable of operating within the frequency range between 3.5 and 7.3 megaHertz will be able to access the 80 , 60 and 40 meters bands, where the NVIS propagation mode is available during many hours of the day. When the NVIS mode is no longer present due to changes in the ionosphere, the radio amateurs then appeal to long distance relays that have proven to be extremely effective. Just to give you an example of the effectiveness of long distance relays, here is a showcase example... several years ago an extremely powerful hurricane caused severe destruction all over the Yucatan peninsula of Mexico...
As expected the telecommunications infrastructure colapsed, and amateur radio operators deployed their equipment to provide much needed traffic that included the request to evacuate people isolated by the floods caused by the heavy rainfall... When they failed to talk with the command posts coordinating the relief efforts because the NVIS propagation mode had vannished , a very effective traffic handling system was routing the messages from near Cancun to La Habana, Camaguey and Santiago de Cuba , so that the Cuban radio amateurs were then relaying the traffic back to Mexico.
Due to the so called evening skip on 40 meters, stations located just 30 or 50 miles away could not establish a link, and that was then solved by using the worldwide cooperation characteristic of the amateur radio hobby.... So amigos, if you happen to be a licensed radio amateur operator, and live within the area that may be affected by tropical storms and hurricanes, get ready to provide those vital links by organizing an emergency communications survival kit !!!
Please send any questions you may have about emergency communications via ham radio. The capability to provide those vitally important links is one of the reasons that valuable radio frequency spectrum space is assigned to amateur operators worldwide.
Now item four , here at the middle of the week edition of Dxers Unlimited, your favorite radio hobby program .... Yes we do QSL, that is, we do verify your reception reports with a very nice QSL card that you can show to relatives and friends while explaining how it is possible to pick up international radio broadcasts from many nations around the world.
And now just before the end of the program here is an update about short wave propagation conditions. Sporadic E layer events continue to provide some very interesting very short skip contacts on the 20, 17 , 15, 12 and 10 meters bands. The solar flux is hovering just around 110 units and there are two areas of sunspots with enough energy to trigger M class solar flares...
Expect short wave radio propagation disturbances during the next 48 to 72 hours ... and when they do happen your chances of picking up rare stations increases.... Send your signal reports and comments about specially unsual DX signals to inforhc at enet dot cu, again inforhc at enet.cu or VIA AIR MAIL to Arnie Coro Radio Havana Cuba, Havana , Cuba
Read more...
|
|
|
Archive
