Radio Havana Cuba Dxers Unlimited's middle of the week program for Tuesday July By Arnie Coro radio amateur CO2KK

Transcription

1 Radio Havana Cuba Dxers Unlimited's middle of the week program for Tuesday July By Arnie Coro radio amateur CO2KK Hola amigos radioaficionados all around the world... You are now listening to the middle of the week edition of Dxers Unlimited, our station's program devoted to the promotion and development of our wonderful hobby... RADIO. I am Arnaldo, Arnie, Coro radio amateur CO2KK the host of this twice weekly show, and here is now our first headline... a submerged, an underwater volcano located very near to the Caribbean island of Grenada is receiving a lot of attention from seismologists around the world. The volcano is showing signs of increased activity and that is why scientists are warning that an eruption may happen at anytime... If it does happen, and depending on the intensity it will require the activation of the Caribban Basin emergency communications networks, including those that are operated by radio amateurs... Once again the radio hobby enthusiasts come forward to offer any possible assistance in case a volcanic eruption generates a tsunami event... Item two: Also emergency communications related... if and when the submerged volcano near the island of Grenada erupts, you will be able to monitor the activity of amateur radio emergency networks on the 80, 40 and 20 meters bands, and if you are within range of the 2 meters band repeaters it will be possible to pick up emergency related traffic of a more local nature. Item three: Solar activity has continued to be at a very low

2 level, but it may increase a bit during the next several days if new solar active sunspot regions come into view. During the past 10 days the solar flux levels dipped down below the one hundred units mark, something that was quite easy to notice because of the very low maximum usable frequency peaks registered during the local daytime hours... Item four: ASK ARNIE, la numero uno, the number one most popular section of Dxers Unlimited according to the e'mail messages and letters that I receive here will answer a question sent by listener Conrad from Germany. Conrad wants to know more about the availability of lower cost short wave radios that are also of good quality. Well amigo Conrad, it seems like the present state of the marketplace regarding the possibility of selling short wave capable radio receivers has shrinked quite dramatically. This has to do with the fast pace of development of the Internet and all computer related technologies... and its impact on the design, production and selling of lower cost, yet well designed and well made short wave radios has shown to be quite significant...according to several Dxers Unlimited listeners that keep track of the radios that can be bought at a reasonable price, the number of options are quite limited and radios sold for less than about one hundred to one hundred and fifty US dollars are to be avoided because of poor design and poor quality of the assembly plus also terribly poor quality control... So be advised, if you want to buy a new radio, keep in mind that this is going to be a signficant investment, so a lot of care must go into the selection process. Please notice that I have focused only on portable AM. FM. And Short

3 Wave receivers using digital frequency displays and with the capability of picking up single sideband, digital and CW signals... Stay tuned for more radio hobby related information coming up in a few seconds after a short break for a station ID. I am Arnie Coro in sunny La Habana, Cuba... Si amigos, Yes! This is Radio Havana Cuba, the name of the show is Dxers Unlimited and here is item five or this middle of the week program...as a long time radio amateur operator, I appreciate very much the quality of my ham radio station's headphones... High quality ones that provide faithful signal reproduction and can be worn for several hours without you wanting to remove them are quite expensive to say the least. But the really good ones are worth all of what you pay for them... I happen to own a pair of four thousand ohms impedance headphones that were rebuilt in order to use a new more comfortable headband, a new much more flexible cable and a high quality male plug. Four thousand ohms impedance headphones are very rare today, and even less efficient two thousand ohms ones are becoming hard to find... The use of solid state audio circuits that match to lower impedance values have made the eight, sixteen or thirty two ohms impedance headphones the ones that can be bought off the shelf... BUT be aware that some of those headphones may look quite nice on the outside, but electrically and acoustically may be of very poor quality... Amazing as this may sound... some very nice looking heaphones with extensive padding and even a

4 sophisticated heaband, may prove to be of very poor quality... In the process of selecting a new headphone, be on the alert for very good looking ones that do not provide the quality of audio reproduction that you want. Of course that you can use earplugs type of listening devices, but as a good friend of mine likes to say... you can judge an amateur radio station by just taking a look at the headphones that the operator has in regular use... By the way, although quite expensive, the headphones that are used by professional pilots are a very nice option if you want quality of reproduction, noise cancellation and comfort... but be aware that the really good ones, with integrated noise cancelling microphones may cost a lot of money... although it is in my opinion a really worthwhile investment... Some amateur radio equipment manufacturers that specialize in audio products also offer high quality headphones and special microphones that are quite expensive and that not always provide the quality that they claim to offer... Loudspeakers for radio hobby use are another quite different story, and YES, they are several designs that offer really outstanding audio quality while also providing options that help to filter noise by means of digital signal processing... Again the really good ones cost a lot of money, But there is always the option of home brewing a nice acoustic cabinet, fit it with a high quality loudspeaker and then you must play with advanced acoustics software in order to achieve the frequency response that you want.

5 For normal radio amateur work, and international broadcast stations listening, a frequency response curve from about two hundred cycles per second to about five kilohertz will be quite useful... But again, you may want to experiment with the home brew acoustic cabinet and louspeaker combination at hand, something that will usually produce quite satisfactory results, and at the same time save you a lot of money!!! And now just at the end of this middle of the week edition of Dxers Unlimited, a reminder that you may send any radio hobby related questions via e'mail to inforhc at enet dot cu, of VIA AIR Mail to Arnie Coro, Radio Havana Cuba, Havana, Cuba, and please if possible do add a signal report and comments about this and other of our station's programs... Now here is Arnie Coro's exclusive and not copyrighted HF plus low band VHF propagation update and forecast... A fast look at the Sun shows an active sunspots region with a beta -gamma magnetic field configuration that may produce M class solar flares during the next three days, the sunspot number count is near 55 and the daily solar flux number is around one hundred... so do not expect long duration daytime openings on frequencies above twenty megahertz... There are still chances of sporadic E layer openings that will gradually be less in number as we move into the month of August... Best time for short wave listening and amateur radio Dxing continue to be from one or two hours after local sunset until sunrise. See you all at the weekend edition of the show amigos!!!!