English French German Spain Italian Dutch Russian Portuguese Japanese Korean Arabic Chinese Simplified



By Arnie Coro

radio amateur CO2KK

Hi amigos radioaficionados , nice to have you listening and sharing with me about seventeen minutes of on the air and on the web time, totally, completely devoted to our radio hobby. I am Arnie Coro, radio amateur CO2KK, your host here at this twice program where you can learn more about radio and obtain also our exclusive and not copyrighted HF plus low band VHF propagation updates and forecasts. Now here is item one: Solar activity takes a nose dive, despite the fact that two active sunspot regions are on sight... the problem is that the two are not generating a lot of energy, so we are seeing something that is difficult to understand even for some experts... while the daily sunspot number may be , for example 28 or 30, at the same time the daily microwave solar flux is down to around 75 units... Amigos, there is still a lot to learn about our nearest star and how it exerts its influence on our planet ! Item two: another ham radio contest during this weekend... and this is a very special one, with the very special emphasis on the use of low power transmitters... It is the QRP -ARCI contest... QRP ARCI stands for QRP Amateur Radio Club International , an amateur radio club that promotes the use of low power communications, and this weekend contest is a good example of this policy, as it gives a multiplier that increases as the participant uses less power to participate. The contest is already in progress at the time that you are hearing this program, it lasts for a total of 36 hours, but the rules call for a 24 hours limit for your participation. In other words, you can choose working the contest for 24 or the 36 hours, but you are not allowed to operate full time, something quite different from the rules of the big ham radio contests that last for 48 hours !

Now imagine many radio amateurs around the world motivated by the challenge of operating their transmitters at powers below 5 Watts !!! Yes, it is quite a challenge, especially for those that will be running at the below 1 Watt output level. I will be participating with a 4 Watts homebrew transmitter that is capable of operating on the 40, 20, 15 and 10 meters band. By the way, following an International Amateur Radio Union's recommendation, the QRP-ARCI contest does not allow operation of the participating stations on the WARC bands, 30, 17 and 12 meters, that are always to be preserved from use by contests. More about QRP fun , a bit later here at the weekend edition of Dxers Unlimited coming to you from sunny Havana, where we have been enjoying a very nice tropospheric ducting VHF-UHF propagation event for the past two days. I am Arnie Coro , radio amateur CO2KK, back with you in a few seconds amigos..


This is Radio Havana Cuba, the name of the program is Dxers Unlimited, and amigos, our e-mail address is inforhc at enet dot cu, again inforhc at enet dot cu, and you can send to it signal reports, comments about this and other programs, and any radio hobby related questions you may want to ASK ARNIE, the most popular section of this show... Now here is item three : As my mentor into amateur radio Ignacio Diaz Perez CM2DK told me when I was just 12 years old, a low power transmitter will be able to communicate half way around the world when two basic conditions are met... first of all, it must be connected to an excellent antenna system and the second element is that the propagation conditions on the frequency used must be in the best possible shape... I remember Ignacio cranking down the power on the two 1625's finals of his rig, by switching off the screen grid supply, something that drastically reduced the output power of the transmitter. He ran that demonstration to visitors to his shack, in order to show them that even with 10 Watts he was able to work many stations on the 40 meters band. Low power operation of amateur radio transmitters is a lot of fun, it is certainly a challenge to your operating skills, and as an added bonus, it does help to reduce CO2 emissions to the atmosphere, because by running powers below the 5 watts range, your rig will need much less electricity to operate, and as everyone knows most of our electric power comes from power stations that use fossil fuels that when burned pollute the atmosphere.

But let me add that there are also other interesting things happening when yourham radio equipment runs at QRP or below 5 Watts power level... If you are operating on battery power, the charge on your batteries will last a lot longer... and this is a very important fact to consider when your station is involved in an emergency communications effort... QRP or low power operation also develops and sharpens your operating skills, again something extremely useful when handling EMCOMMS ,as emergency communications are also known among radio amateurs. Last but not least, home brewing your own QRP or low power transmitters is a lot easier and less difficult than when you are dealing with radio frequency output stages that are running higher powers... And don't forget that there is nothing as enjoyable as making a nice two way amateur radio contactusing a transmitter that you have build all by yourself, or with the help of a friendly and more experienced radio amateur.

I am writing this script when the start off of the QRP ARCI contest is just a few minutes away, and my 4 Watts transmitter is already connected to the big outdoor antenna system... Propagation conditions are not that great during this weekend, due to the lower solar activity, but nevertheless, I'll be there operating on and around the QRP parking spots, the frequencies where QRP operators usually call CQ to generate activity using low power rigs... There are three very popular QRP frequencies that I frequently monitor here in Havana... first of all 14 060 kiloHertz, again 14060 kiloHertz on the 20 meters ham band, that is perhaps the most popular QRP frequency of them all... Then on the 40 meters band , there are two frequencies in use, one popular among Europeans, and the other popular among QRP operators in the Americas... They are 7030 and 7040 kiloHertz, again 7030 and 7040 kiloHertz, but unfortunately they are both now under siege by the expansion of the digital modes that are becoming extremely popular all around the world... Let me also mention the 15 meters band QRP favorite frequency that happens to be 21060 , while on 10 meters is is 28060 kiloHertz. Si amigos, yes my friends, oui mes amis... even with just less than 5 watts you can not only enjoy nice two way CW Morse Code radiotelegraphy contacts... there are many QRP operators that run at those low power levels using single side band voice mode and achieve some very nice results too, although I must admit that it is easier to make QRP contacts on CW of course...


ASK ARNIE, si amigos !!! sure ASK ARNIE continues to be the most popular section of the program as I constantly receive radio hobby related questions from all around the world... Each and every question is answered as soon as possible, but sometimes there are so many that I have to work some extra hours to catch up with the backlog... Today I will be answering a question that was sent by listeners in North America, Europe, Africa and Australia... They all want to know how much an amateur radio station , completely installed and ready to operate amateur radio station will cost.... Well my friends, that is really an almost impossible to answer question, because the cost of a station will depend on many decisions that you must take … For example, you can start your ham radio career on a shoestring budget, by visiting the hamfests and radio clubs and searching for a good quality 2 meters band FM handie talkie... or even look for the not too expensive new ones that are not aiming at the high end of the market. All around the world the 2 meters ham band seems to be the most popular of them all, and the fact that many telecommunications services use frequencies adjacent to the two meters band has also helped to reduce the cost of those radios. At my Plaza Radio Club, we have learned how to reprogram professional 2 meters band hand held radios that are removed from service by companies that switch over to new communications technologies... Sometimes those HT's or handie talkies can be easily reprogrammed while achieving the same performance that they had on the original band of frequencies to which they were set to operate, but sometimes we do notice a slight degradation of the performance, like for example the loss of receiver sensitivity or the transmitter power output. Even if this happens, the reprogrammed hand held FM two meters band transceiver can still be used for local communications, and it will certainly access the repeaters too !!! So, that's in my opinion , at this particular moment , the lowest cost ham radio station that you can think of …. The second option will be to get involved in home brewing HF equipment, that is radios capable of operating within the frequency range between 3.5 and 29.7 megaHertz... Just a few days ago I arranged a demonstration of a low power or QRP ham radio station using a portable short wave receiver that has a BFO or Beat frequency oscillator, the SONY ICF-7600 -GR and a homebrew 5 watt transmitter operating on the 20 meters amateur band...and using a very simple half wave dipole antenna fed with RG58U coaxial cable . The demonstration was done at a time of the day when propagation conditions were best on 20 meters and during a half hour operating session, I was able to make several nice two way CW contacts with stations in three countries, Canada, the USA and Mexico...

The two visitors that watched the demonstration went home with the circuit diagram and some parts to build their own Morse Code practice oscillators , because as they said, it was now quite clear to them that CW is the most fascinating operating mode of them all... I hope to hear them soon on the air, something that will need to wait until they take their second class amateur radio license test, the one that here in Cuba allows for many operating privileges on the 80 to 10 meters amateur bands.

And now amigos as always at the end of the program , here is our HF plus low band VHF propagation update and forecast.... it is not copyrighted, it is in the public domain , so you can freely reproduce it so that others may enjoy short wave radio at its best... Solar activity is at very low levels, with the daily solar flux figure nosediving down to below 75 units... Correpondingly the daytime maximum useable frequencies curve has gone down several megaHertz from what we were seeing just two weeks ago. The best night time band for ham radio Dxing will be 40 meters, and 20 meters will be closing down much earlier because of the lower solar activity... For short wave listeners the best day time bands will be 19 and 16 meters … I hope to have you listening to the mid week edition of Dxers Unlimited next Tuesday and Wednesday UTC days, and don't forget to set aside a little moment at your computer and send me your comments about today's program , send mail to inforhc at enet dot cu, again inforhc at enet dot cu . VIA AIR MAIL our postal mailing address is Arnie Coro, Radio Havana Cuba, Havana , Cuba

0 comentarios:

Publicar un comentario


Google+ Followers

Este sitio utiliza cookies, puedes ver nuestra la política de cookies, aquí Si continuas navegando estás aceptándola
Política de cookies +