RADIO HABANA CUBA
DXERS UNLIMITED
WRITTEN BY ARNIE CORO
MIDWEEK EDITION
TUESDAY, 2 DECEMBER 1997
SEND YOUR COMMENTS, QUESTIONS AND IDEAS DIRECTLY TO ME AT: arnie@radiohc.org
HI, WELCOME TO THE MID-WEEK EDITION OF YOUR FAVORITE LISTENER ORIENTED RADIO HOBBY SHOW... I AM ARNIE CORO, RADIO AMATEUR CO2KK, YOUR FRIEND HERE IN HAVANA AND HOST OF THIS TWICE WEEKLY PROGRAM.
NOW, THE MENU FOR TODAY...
ITEM ONE: SOLAR ACTIVITY WENT UP TO THE HIGH CATEGORY... SOLAR FLUX HOVERING ABOVE 110 ... SEVERAL SOLAR FLARES... BUT SO FAR NO GEOMAGNETIC DISTURBANCES... AT LEAST UNTIL AROUND NOON TUESDAY WHEN THIS SCRIPT WAS WRITTEN...
ITEM TWO: CQ WORLDWIDE CW CONTEST PARTICIPANTS ENJOYED NICE PROPAGATION ESPECIALLY ON 40, 20, AND 15 METERS... CONDITIONS ON 80, ALTHOUGH GOOD WERE A LITTLE NOISY, AS WELL AS ON 160, WHILE 10 METERS FAILED TO PROVIDE THE MANY CONTACTS SOME EXPECTED ON THAT BAND.... MORE ON THE CONTEST NEXT SATURDAY AND SUNDAY UTC WHEN ILL TELL YOU ABOUT T49C, THE CUBAN SCANDINAVIAN JOINT DX EXPEDITION THAT TOOK PART IN THE CONTEST
NOW, ITEM THREE: NEW E-MAIL ADDRESS FOR DXERS UNLIMITED... SI, AMIGOS !!! A NEW, EASY TO REMEMBER, AND EASY-TO-COPY-VIA-THE-AIRWAVES E-MAIL ADDRESS FOR DXERS UNLIMITED IS NOW AVAILABLE.... IT'S REALLY SIMPLE...
READY TO COPY..... arnie@radiohc.org
YES, JUST arnie@radiohc.orgTHE TECHNICAL TOPICS SECTION:
TECHNICAL TOPICS IS ONE OF THE MOST POPULAR SECTIONS OF THE SHOW... AMONG OTHER THINGS,BECAUSE ACCORDING TO YOUR LETTERS, E-MAIL, FAX AND PHONE IN REPORTS, YOU GET ANSWERS TO YOUR QUESTIONS IN AN EASY TO UNDERSTAND WAY.... HERE IS TODAY'S QUESTION... ARNIE, WITH SO MANY DIFFERENT TYPES OF COAXIAL CABLES AVAILABLE... WHICH IS THE ONE I SHOULD USE FOR MY SHORTWAVE RECEIVING ANTENNA... ????
BY THE WAY, THIS QUESTION CAME FROM LISTENERS IN SOUTH AFRICA, CANADA, THE USA, CANADA AND COLOMBIA...
HERE IS THE ANSWER...
FOR ALL PRACTICAL PURPOSES, ANY GOOD-QUALITY, WELL-PRESERVED OR NEW COAXIAL CABLE WILL WORK VERY WELL AT THE SHORTWAVE REGION OF THE SPECTRUM, FROM 3 TO 30 MEGAHERTZ... THERE IS ONE POSSIBLE EXCEPTION... AND THAT IS THE VERY THIN AND ULTRA LIGHT RG174-U COAX, WHICH YOU SHOULD AVOID BECAUSE IT WILL NOT HOLD WELL UNDER HEAVY WINDS ... ALL OTHER CABLES, USED AND WELL PRESERVED OR BRAND NEW WILL WORK VERY WELL WHEN THE CABLE RUN FROM THE ANTENNA TO THE RECEIVER IS KEPT UP TO ABOUT 100 METERS OR 330 FEET...
YES, YOU CAN RUN NO LESS THAN 100 METERS OR 330 FEET OF COAX FROM THE ANTENNA TO THE RADIO AND STILL ENJOY GOOD PERFORMANCE FROM 3 TO 30 MEGAHERTZ, AS LOSSES WILL NOT BE TOO HIGH, EVEN AT THE EXTREME END OF THAT FREQUENCY RANGE...
NOW, BE CAREFUL, BE EXTREMELY CAREFUL WITH USED COAX.... IT CAN BE A KILLER !!! OLD, CONTAMINATED, CORRODED CABLES WILL SHOW VERY HIGH LOSSES... SO, DO CHECK THE CONDITION OF THE CABLE VERY CAREFULLY IF YOU ARE GOING TO USE ONE THAT WAS PREVIOUSLY USED...
ONE QUICK WAY OF KNOWING HOW GOOD, OR HOW BAD THE CABLE HAS KEPT IS BY CUTTING AWAY ABOUT 50 CENTIMETERS, OR ROUGHLY 2 FEET FROM EACH END, REMOVING THE PLASTIC COVER, AND TAKING A GOOD LOOK AT THE CABLE'S COPPER BRAID OR SHIELD... ANY SIGNS OF CORROSION, CHANGES IN COLOR OR THE PRESENCE OF HUMIDITY IS A GOOD REASON TO DISCARD THE CABLE AND SEND IT TO THE RECYCLING BIN....
NOW, A SECOND TIP... WHEN INSTALLING YOUR NEW ANTENNA WITH YOUR NEW OR VERY WELL KEPT COAX, GO ALL OUT FOR PROTECTION AGAINS HUMIDITY AND CORROSION DAMAGE... THE TIME AND RESOURCES SPENT IN PROTECTING THE CABLE WITH SPECIAL PLASTIC TAPES, SILICONE COMPOUNDS ETC WILL MORE THAN COMPENSATED WITH YEARS OF PERFECT OPERATION OF YOUR ANTENNA SYSTEM....
NOW A THIRD TIP... EVEN VERY WELL INSTALLED COAXIAL CABLES... WITH ALL POSSIBLE MEANS OF PROTECTION AGAINST WEATHER, DO NEED A CHECK EVERY TWO YEARS OR SO... TAKING APART THE TAPE AND SILICONE COMPOUND MAY BE A PROBLEM... BUT IT'S WORTH IT, BECAUSE YOU MAY FIND THAT MAYBE A LITTLE CRACK HAD DEVELOPED, AND THE SEALING IS NO LONGER PERFECT... GOOD ENGINEERING PRACTICE CALLS FOR YEARLY INSPECTION OF THE CABLES AND CONNECTORS AND A COMPLETE REPLACEMENT OF THE ANTI-CORROSION AND HUMIDITY PROTECTION EVERY TWO YEARS...
SO... NEXT TIME YOU SEE THAT BRAND NEW ROLL OF TV TYPE COAX AT THE HAMFEST OR FLEA MARKET... TAKE A GOOD LOOK AT THE CABLE'S END... CLEAR THE PLASTIC COVERING WITH A KNIFE, AND IF ITS BRIGHT AND SHINNY ... AND THE PRICE IS RIGHT... TAKE IT HOME AMIGO !!!
DON'T WORRY ABOUT ITS IMPEDANCE OR THEORETICAL LOSSES PER 100 FEET OR 30 METERS... FOR HF APPLICATIONS, ESPECIALLY FOR RECEIVING FROM 3 TO 30 MEGAHERTZ... ANY MODERN COAX CABLE WILL WORK NICELY FOR YOU !!! BUT BEWARE... VHF AND UHF IS ANOTHER STORY..
IF YOU REALLY WANT TO LEARN HOW TO MAKE COAXIAL CABLES LAST LONG GET IN TOUCH WITH THE CABLE TV TECHNICIANS THAT SERVE YOUR COMMUNITY, IF, OF COURSE, YOU HAVE CABLE TV AVAILABLE... CABLE TV TECHNICAL PERSONNEL HAVE THE KNOW-HOW ON THE TECHNNIQUES FOR SOLDERING CONNECTORS, SPLICING, KNOWING WHEN A CABLE IS IN GOOD SHAPE ETC... BUT ABOVE ALL THEY KNOW A LOT ABOUT HOW TO SEAL THE COAX AND CONNECTORS FROM THE WEATHER, AND THEY WILL HAVE THE APPROPIATE TAPES AND SILICON COMPOUNDS THAT WORK BEST IN YOUR AREA TOO !!!
IN A FUTURE EDITION OF DXERS UNLIMITED, RIGHT HERE AT OUR TECHNICAL TOPICS SECTION, I'LL TELL YOU ABOUT COAXIAL CABLE S FOR VHF AND UHF, WHICH DO REQUIRE SOME VERY SPECIAL CONSIDERATIONS.
NEW FAST AND EASY E-MAIL ADDRESS
THIS IS DXERS UNLIMITED... AND I HAVE A NEW, EASY TO REMEMBER E-MAIL ADDRESS NOW AVAILABLE... TRY IT... SEND ME A NICE SIGNAL REPORT AND SOME COMMENTS ABOUT TODAY'S SHOW TO.... arnie@radiohc.org
AGAIN, VERY SLOWLY AND PHONETICALLY.... arnie@radiohc.orgPLEASE DO REMEMBER TO INCLUDE IN YOUR E-MAIL YOUR POSTAL ADDRESS SO THAT I CAN SEND YOU A HARD COPY QSL CARD FOR YOUR REPORT...
IF YOU ARE NOT YET IN CYBERSPACE... USE AIR MAIL TO SEND YOUR SIGNAL REPORT AND COMMENTS ABOUT THE SHOW.... THIS IS ALSO AN EASY ADDRESS... ARNIE CORO, DXERS UNLIMITED, RADIO HAVANA CUBA, HAVANA CUBA...
DOCTOR'S OFFICE WAS CAUSING THE INTERFERENCE TO SHORTWAVE RADIO
TROUBLED BY A BUZZING SOUND WHILE TRYING TO TUNE HIS SHORTWAVE RECEIVER, A DXERS UNLIMITED LISTENER CAME ACROSS A VERY INTERESTING SOURCE OF INTERFERENCE TO SHORTWAVE RECEPTION... MEDICAL EQUIPMENT !!! HE FOUND THAT THE DOCTOR'S OFFICE IN THE SAME APARTMENT COMPLEX WERE HE LIVES WAS THE SOURCE OF THE BUZZING SOUND HEARD INTERMITTENTLY ALL OVER THE SHORTWAVE SPECTRUM... AS IT HAPPENS, THE DOCTOR WAS USING A SHORTWAVE DIELECTRIC HEATING SET FOR THE TREATMENT OF SOME OF HIS PATIENTS... THIS LISTENER TOLD ME THAT THE DIELECTRIC HEATER OPERATED ON THE 27 MEGAHERTZ MEDICAL EQUIPMENT BAND... USING FAIRLY HIGH POWER AND VERY LONG CABLES TO THE HEATING PADS THAT ACTED AS VERY GOOD ANTENNAS !!!... THE VERY OLD DIELECTRIC HEATER LACKED PRESENT DAY FILTERING TECHNOLOGY, AND MOST OF THE BUZZING NOISE WAS COMING NOT FROM ACTUAL RADIATION VIA THE HEATING PAD LEADS, BUT VIA THE AC POWER LINE.... CONNECTING THE DIELECTRIC HEATER MACHINE VIA A LINE FILTER REDUCED THE INTERFERENCE TO A VERY NARROW SEGMENT OF THE SHORTWAVE SPECTRUM CENTERED BETWEEN 25 AND 30 MEGAHERTZ...
SO, NEXT TIME YOU HEAR A STRANGE NOISE ON THE RADIO AND THERE IS A DOCTOR'S OFFICE OR A HOSPITAL NEARBY...YOU MAY WANT TO LOOK AROUND FOR POSSIBLE MEDICAL EQUIPMENT CAUSED INTERFERENCE...
LATE AFTERNOON EDITION OF DXERS UNLIMITED ALSO AVAILABLE ON 6000 KHZ
DXERS UNLIMITED COMES TO YOU TWICE WEEKLY ... OUR NORTH AMERICA FIRST EDITION GOES ON THE AIR AT AROUND, ACTUALLY JUST AFTER 2300 HOURS UTC, THAT IS 6 PM EASTERN STANDARD TIME, 5 CENTRAL, ON THE 6000 KILOHERTZ 49 METER BAND FREQUENCY... ONCE AGAIN, DXERS UNLIMITED IS AVAILABLE ON ITS LATE AFTERNOON EDITION AT 6 PM EASTERN, 5 PM CENTRAL ON THE 6000 KILOHERTZ, 49 METER BAND FREQUENCY... AT THAT TIME WE ARE USING 100 KILOWATTS AND OUR PHASED DIPOLES ANTENNA ARRAY PROVIDING COVERAGE OF THE CARIBBEAN AND THE SOUTHEASTERN UNITED STATES... LATER IN THE EVENING ALSO ON 6000 KILOHERTZ YOU CAN PICK UP DXERS UNLIMITED AT 0130, AND 0330 UTC...
TV DX REMINDER ... GET READY FOR THE UPCOMING WINTER SPORADIC E SEASON
YES, TV DXERS ARE GETTING READY FOR THE UPCOMING WINTER SPORADIC E DX SEASON.. A SHORT BUT VERY INTERESTING SEASON CENTERED AROUND THE NEW YEAR, BUT SPANNING FROM ABOUT DECEMBER THE 15TH TO JANUARY THE 15 TH... SOME EXPERTS BELIEVE THAT THIS SHORTLIVED WINTER SPORADIC E SEASON IS SOMEHOW CONNECTED TO THE SUMMER DX SEASON OCURRING AT THIS TIME IN THE SOUTHERN HEMISPHERE... ANYWAY... TV DX ON CHANNELS 2 TO 6 IN THE AMERICAS, AND THE FEW EUROPEAN STATIONS STILL OPERATING FROM 48 TO 52 MEGAHERTZ IS COMING UP... BE READY FOR THOSE ELUSIVE E SKIP SIGNALS... HAVE YOUR CAMERA READY, AND KEEP THAT VCR ROLLING WHEN DX IS COMING IN... THERE IS NO BETTER WAY OF GETTING A QSL FROM A TV STATION THAN SENDING THEIR CHIEF ENGINEER A NICE PICTURE OR A TAPE OF HOW YOU SAW HIS STATION MAYBE ONE OR TWO THOUSAND MILES AWAY !!
HERE IS ARNIE CORO'S EXCLUSIVE AND NOT COPYRIGHTED
PROPAGATION UPDATE AND FORECAST...
PREPARED MONDAY 1 DECEMBER AT 1700 UTC *EXPECT SOLAR ACTIVITY TO CONTINUE FROM MODERATE TO HIGH... SOLAR FLUX WILL STAY ABOVE THE 100 UNITS MARK... DAYTIME MAXIMUM USEABLE FREQUENCIES WILL SOAR ABOVE 25 MEGAHERTZ FOR SEVERAL HOURS EACH DAY.. NIGHTIME RECEPTION WILL BE EXCELLENT ON FREQUENCIES FROM 7 TO 12 MEGAHERTZ... BUT... BE ON THE LOOK OUT FOR POSSIBLE GEOMAGNETIC DISTURBANCES AND SUDDEN IONOSPHERIC ABSORPTION EVENTS... THEY MAY COME AT ANYTIME DUE PRECISELY TO THE HIGH SOLAR ACTIVITY PERIOD WE ARE NOW GOING TROUGH...
* NOTE: LAST-MINUTE ON-AIR CHANGES MAY BE MADE IN THIS FORECAST IF PROPAGATION CONDITIONS CHANGE SUDDENLY.
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