DXERS UNLIMITED DXERS UNLIMITED'S WEEKEND EDITION FOR 28-29 JULY 2007 BY ARNIE CORO RADIO AMATEUR CO2KK
Hi amigos radioaficionados ! Welcome to the weekend edition of your favorite radio hobby program, the one and only that provides information about the more than eighty one ways you and I enjoy playing with our radios !!! For you amigos that are listening for the first time my best wishes, and I hope to you have join me twice every week to learn more about the wonderful radio hobby in a year during which solar activity is expected to continue declining as we transit towards the end of solar cycle 23, one of the most interesting ones on record... Si amigos, it's your friend Arnie Coro in Havana, ready to share with you all about seventeen minutes of on the air and on the web time, and thanks to the Ontario DX Association you can also read our scripts by subscribing to the ODXA Yahoo mailing list... Now here is item one : E-mail messages reaching my computer everyday speak highly of Dxers Unlimited's listeners around the world, as many of you mention an interest in learning more about amateur radio and how you can join radio clubs . Amateur radio is one of the finest areas of the radio hobby , and more than two million people worldwide that have licenses to operate amateur radio stations can't be wrong !!!. As a matter of fact, despite some dreadful forecasts about the negative impact of the Internet and computers on the radio hobby in general and amateur radio in particular, the opposite seems to be the truth, as both the Internet and computers have proven to be a remarkeable assett helping to develop the radio hobby into new and never before seen activities... For those of you not familiar with the extraordinary amount of online information about amateur radio that is provided absolutely free of charge, my advice is to run a search on Internet by typing amateur radio and just sitting down to watch the results... Try it, and you will agree with me that the prophets of the doomsday of amateur radio due to the Internet were fortunately mistaken !!! And YES we can still do a lot more to promote this wonderful aspect of the radio hobby that helps people around the world to communicate with each other , even from places where wired connectivity is ZERO !!! Item two: How many radios , yes how many radio receivers do you happen to own ?? Everyone in developed nations has at least two radios available for listening, and some people have even more !!! If you are a short wave listening enthusiast and already own a nice short wave radio, follow your friend's Arnie Coro's advice and try to get a second receiver... As you become a more advanced short wave listener, you will find yourself leaving one receiver on a certain frequency taping a yet unidentified station for later analysis, while the other radio is used for listening to a program you enjoy ,like for example ... YES, Dxers Unlimited !! Monitoring the short wave radio spectrum with two receivers at the same time is a very rewarding experience, as you can learn a lot about how international shortwave broadcast stations use satellite links to deliver the audio to remote transmitting sites !!! Item three of today's Dxers Unlimited will be our technical topics section, item four, the popular you have questions and Arnie tries to answer them and as always when I am here in Havana, at the end of the program, have your tape recorder or notepad ready to copy our exclusive and not copyrighted HF plus low band VHF propagation update and forecast amigos... Stay tuned , Dxers Unlimited coming to you from Radio Havana Cuba will continue in a few seconds... ...... The radio hobby amigos is really fascinating,and in order to enjoy at its maximum , you must make an effort to learn about the technical aspects involved. In the beginning this may seem difficult,but little by little, and as time goes by, you will find yourself learning a lot about topics like electronics, antennas and radio wave propagation... That's the main purpose of Dxers Unlimited's TECHNICAL TOPICS SECTION... and here is an example..The two meters amateur VHF band is considered by many as the most popular one around the world, and those who think so may be quite right, as rather inexpensive and easy to operate FM handheld transceivers, popularly known as handie-talkies , have helped to populate two meters with the aid or repeaters located at high rise locations like mountain top TV and FM station's sites and downtown high rise buildings. Many radio amateurs start their ham careers by obtaining the basic license and buying a 2 meter band FM hand held... that provides them with the first contact with the hobby. That's why I am always trying to learn more and experiment about simple low cost homebrew antennas that can extend the range of the typical one to five Watts output Fm handie-talkie for the two meter band. One of my most recent experiments originated when I read an article published by ANTENNEX,an on line WEB E-zine that is totally devoted to antenna related topics. The antenna that I tried to homebrew from the ANTENNEX article data is a version of the so called DDRR or Directional Discontinuity Ring Radiator, one of the most interesting antennas that I have ever seen in my long time of enjoying amateur radio. The version of the DDRR for 2 meters is extremely compact and can be made in a couple of hours using simple tools...You won't need to be a mechanical or electronic genius to homebrew this antenna. All what is needed is a square of high quality copper clad printed circuit board of 10 by 10 inches, or roughly 25 by 25 centimeters, that acts as an almost perfect ground plane for the DDRR antenna. The DDRR radiating element is very easy to make and adjust to a perfect one to one standing wave ratio match... As a matter of fact, after testing the roughly built first prototype, I immediately started to think about building two more of them, one for my son's station CM2KW, and another one for my portable emergency communications package, because this is a very low profile antenna that will stay up even under very heavy winds. The DDRR is easy to homebrew , and its low height above the ground plane makes it, as I just said, ideal for use during severe weather conditions. I have both text and graphic information about the 2 meter band Directional Discontinuity Ring Radiator, or DDRR antenna ready to be sent to you amigos... just send an e-mail to [EMAIL PROTECTED], again, slowly [EMAIL PROTECTED], and request the 2 meter band DDRR antenna project files... If not yet in cyberspace, just send a postcard to Arnie Coro, Radio Havana Cuba, Havana, Cuba, and I'll send you a printed copy of the DDRR antenna for the two meter band... ..... Now here is our very popular you have questions and Arnie answers them section of the program. Today's question sent by listener Karl in Vienna , Austria.... He wants to know if he can use an underground antenna for his HF bands amateur radio rig, as that seems to be the only possible solution for him... Well amigo, let me tell you that carefully installed and well engineered underground antennas do work very well indeed !!! As a matter of fact, you may find that feeding an underground antenna with about 100 watts of radio frequency power, your signal will be heard within a certain area sorrounding the station with very good intensity, due to the so called near vertical incidence skywave propagation. ... The undeground antenna's behavior will show a rather high loss, compared to a standard full size half wave dipole antenna installed at no less than a quarter wavelengh above ground.. the underground antenna will show a loss anywere between 6 and 24 decibels below a standard half wave dipole installed at one quarter wavelength above ground ... So you will need to run more power into it than what normally you will operate with... anyway, there is another added bonus: underground antennas pick up much less man made noise, so reception with them in the frequency range from 160 meters to 40 meters is sometimes better than with an above ground antenna system... Surprising as this may sound to those of you not familiar with antenna technology, underground antenna systems are in regular use by professional telecommunications systems with very special requirements, and they are well known to antenna designers !!! So amigo Karl, start digging your garden , buy yourself large diameter PVC pipe and install your underground antenna as soon as possible to start enjoying the 80, 40 and 30 meter bands you told me in your e-mail that you want to start working ... BUT, don't expect a lot of DX from your underground antenna system... !!!! I Si amigos, you are listening to Dxers Unlimited, this is our mid week edition that is on the air Tuesday and Wednesdays UTC days... you can send for our nice QSL cards by mailing a signal report and comments about this and other Radio Havana Cuba's program to [EMAIL PROTECTED], or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana , Cuba... And now amigos, just before going QRT, here is our number two most popular section of Dxers Unlimited, Arnie Coro's HF plus low band VHF propagation analysis, updates and forecasts.. Very poor HF propagation conditions expected during the next three to five days... extremely low solar activity is keeping the ionosphere's ionization at extremely low levels... So , my advice is to monitor the bands above 10 megahertz after your local sunset amigos... Solar flux near rock bottom minimum of 67-70 units, with six days in a row of absolutely NO Sunspots ... Sunspot count ZERO for a whole week ... Send your signal reports and comments to [EMAIL PROTECTED] or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba ---[Start Commercial]--------------------- Preorder your WRTH 2007: http://www.hard-core-dx.com/redirect2.php?id=wrth2007 ---[End Commercial]----------------------- ________________________________________ Hard-Core-DX mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/hard-core-dx http://www.hard-core-dx.com/ _______________________________________________ THE INFORMATION IN THIS ARTICLE IS FREE. It may be copied, distributed and/or modified under the conditions set down in the Design Science License published by Michael Stutz at http://www.gnu.org/licenses/dsl.html
