[HCDX] Dxers Unlimited´s mid week edition for 8-9 April 2008

["Prof. Arnaldo Coro Antich" <coro@xxxxxxx>]

*Radio **Havana** **Cuba***

*Dxers Unlimited*

*Dxers Unlimited´s mid week edition for 8-9 April 2008*

*By Arnie Coro*

*Radio amateur CO2KK*



Hi amigos radioaficionados around the world and those of you orbiting 
planet Earth too... I am Arnie Coro, radio amateur CO2KK in Havana and 
here is our first news item of today´s Dxers Unlimited.... According to 
several groups of scientific researchers involved in the analysis of 
solar activity, the still ongoing solar cycle number 23 may be the one 
with the longest most extended period of extremely low activity. In 
other words and in plain language, cycle 23 has extended its minimum 
beyond any of the forecasts and may be a record breaking solar event as 
compared with the last seven solar cycles.

So amigos, we must continue to wait until solar cycle 24 really starts 
changing what is happening 93 million miles away from us and that has 
such a tremendous impact here were we all live : Planet Earth.

Item two: Still catching up with the e-mail backlog , and the reason is 
no other than the fact that many of the messages sent by Dxers Unlimited 
listeners around the world include radio hobby related questions that do 
require comprehensive and easy to understand answers, something that , 
believe me, is not an easy job at all...

But don´t worry my friends, because each and every e-mail, postcard , 
letter or FAX received here is answered as soon as possible.

And of course, some of those questions are answered also on the air for 
the benefit of other listeners that may then learn more about the hobby.

There are many examples of how our YOU HAVE QUESTIONS and Arnie tries to 
answer them section of the program has helped radio hobby fans to solve 
some of the problems that they may have. Here is a recent example: A 
recent reply about the challenges that repairing present day 
sophisticated radio and other electronic equipment , led to several 
listeners deciding to buy or homebrew the so called ESR or equivalent 
series resistance meters, a test instrument that has really changed the 
way electronic technicians approach the repair of broken down 
equipment... More about the ESR meter and how it has helped to rescue a 
lot of broken down radios that were thought to be beyond repair , later 
in today´s program.

Stay with us amigos, as Dxers Unlimited will continue after a short 
break for station ID...

I am Arnie Coro in Havana...



........................

This is Radio Havana Cuba, the name of the show is Dxers Unlimited, and 
si amigos, sure, we do QSL, we do verify your reception reports 
absolutely free of charge and VIA AIR MAIL, as we believe, from the very 
first day that we went on the air , that international shortwave 
broadcasters must develop very good ties with their listeners , and one 
way of doing it is precisely by verifying reception reports...

Now, let me continue with today´s Technical Topics section of the 
program, that is devoted to what many electronic engineers and 
technicians consider to be an outstanding breakthrough in the repair of 
broken down equipment...

I am talking about the ESR or Equivalent Series Resistance Meter, a 
relatively simple test instrument that provides the repairman with most 
reliable information about the state of electrolytic capacitors, the 
electronic components that according to very trustworthy statistics 
account for the greatest number of electronic equipment failures during 
the past 20 years...

A repair technician that has access to an ESR meter will be able to fix 
equipment in a much faster and easier way, while at the same time he 
will be able to do advanced diagnostics that will allow the preventive 
replacement of electrolytic capacitors even before the equipment shows 
any signs of failure, including the challenging intermittent faults that 
are so typical of bad electrolytics ...

One very interesting fact about the ESR meters is that you can learn how 
to use them very easily , and that the interpretation of the meter´s 
readings will lead to the decision of replacing capacitors that you will 
never had thought that required to be changed.

There are several very good designs of ESR meters,  from a very simple 
one that uses an already existing oscilloscope as its output indicator, 
to an expensive model that provides digital readings of the equivalent 
series resistance, the parameter that provides the most reliable 
information about the state of electrolytic capacitors of any type, and 
by that I mean that tantalum capacitors can also be tested with the ESR 
meters.

Finally, let me add that you won´t need to desolder the electrolytic 
capacitors from the printed circuit boards in order to test them with 
the ESR meter, because in my opinion the most outstanding feature of 
this unique test instrument is that it is used by placing the two test 
probes to the terminals of the electrolytic capacitors and reading the 
result of the test directly on the instrument´s meter.

On my second homebrewed ESR meter, the instrument´s output meter 
movement was calibrated using a large number of both good, not so good 
and bad capacitors, and no matter how they were intermixed, the ESR 
meter always found the actual state of the capacitor beyond any possible 
doubts.

If you figure out that bad or in poor shape and not yet really bad 
electrolytic capacitors are the main cause of present day electronic 
equipment failures, it is easy to figure out how important this 
relatively new test instrument has become for performing electronic 
equipment repairs.

Also, it must be underscored that radio receivers, transmitters, and 
transceivers that are more than ten to fifteen years old usually hide 
many electrolytic and tantalum capacitors that may be starting to show 
signs of problems that eventually will lead to breakdowns that can be 
prevented by checking all the electrolytics with an ESR meter ... Sure, 
it will take some time to do it, but it will be worth every minute spent 
doing it, as I have found out here at my electronics and radio workshop 
amigos...

Finally, the ESR meter is of tremendous help also when computer 
motherboards fail, as one of the main causes of those failures are bad 
electrolytics !!!

For technically minded Dxers Unlimited´s listeners, I have here ready to 
be sent, several computer files with information on how to homebrew your 
own Equivalent Series Resistance Meter . Send your request for the ESR 
meter files to inforhc at enet dot cu... Again, inforhc at enet dot 
cu...  With just a few electronic components and several hours of your 
spare time, you will be able to assemble a really useful electronic test 
instrument that will be really useful to repair broken equipment.

.............................

Si amigos, yes my friends, oui mes amis, you are now listening to your 
favorite radio hobby program, Dxers Unlimited  with Arnie Coro...

And now here is our next feature here:

March the 30^th marked the day that international short wave 
broadcasters started to use the new A08 schedule, that will be used 
until October. According to the International Telecommunications Union, 
the administrations must file the use of the short wave broadcast bands 
twice every year, and a year that , by the way, does not coincide with 
the actual year that begins on the first day of January and ends on the 
31^st of December... The A period starts in March and lasts until 
October and the B period starts in October and lasts until March, 
something that was done in order to simplify the previous scheduling 
system that implied four frequency changes per year.

The broadcasting schedules are sent to the ITU in Geneva to be 
registered in the general data base that is kept there, and the 
telecommunications administrations can see how their registered stations 
are providing services to the target areas, if there are any collisions 
of frequencies and the effects of adjacent channels too.

Since Radio Havana Cuba went on the air in 1961, the Cuban Ministry of 
Communications has registered the use of our station´s frequencies with 
the International Telecommunications Union in Geneva, that is the United 
Nations oldest specialized agency, since its origins can be found way 
back in 1865, when several nations started to coordinate the use of the 
Morse wired telegraphy lines ...

The existence of voluntary frequency coordination groups around the 
world is also recognized by the ITU, but it is left to the decision of 
the national telecommunications administrations to participate or not 
participate in those not official groups that may have a regional or a 
worldwide scope.

So, again and to make it very clear to those listeners that have 
recently asked about the topic of frequency coordination, let me 
emphasize that what the ITU requests is that the national 
telecommunications send to Geneva the data about the use of the short 
wave broadcast transmissions according to a previously arranged time 
schedule, then the data is processed and results are sent back to the 
administrations showing how each entry behaves in relation to other 
entries on the same frequency and others that operate on adjacent 
channels 5 kiloHertz to each side of the frequency that is analyzed.

So, in other words, an administration may decide to join or not to join, 
to participate or not participate as part of frequency coordination 
groups or nation , but independently of forming part or not forming part 
of one or more coordinating groups, the

Telecommunications Administrations must file with the ITU in Geneva and 
register the use of each frequency by providing a set of well known 
transmission parameters that include transmitter power, antenna types, 
target areas CIRAF zones to be served etc.

The data is processed by the ITU using sophisticated computer software 
and the results are sent back to each administration so that the 
broadcast schedules can be optimized to the best possible extent...



-------------------



And now amigos, just before going QRT here, ready to copy, this is Arnie 
Coro´s Dxers Unlimited´s HF plus low band VHF propagation update and 
forecast ... solar activity still at the bottom of the cycle´s very much 
extended minimum,ZERO SUNSPOTS , with  solar flux at rock bottom 69 
units and the A index was near 15 yesterday... So don´t expect DX 
stations to show up above 17 or 18 megaHertz during the local daytime 
hours , while during the evening hours propagation conditions will be 
good only to around 10 or maybe 12 megaHertz... No signs of sporadic E 
openings yet, but I expect those openings to start by the end of the 
month amigos !!! Send me your signal reports and comments about the 
program to inforhc at enet dot cu, or VIA AIR MAIL to Arnie Coro, Radio 
Havana Cuba, Havana, Cuba



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