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Re: [HCDX] Dxers Unlimited's weekend edition for 29 -30 September 2007
Radio Habana Cuba
Dxers Unlimited
Dxers Unlimited's weekend edition for 29-30 Sept 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 tries hard to
cover all the more than 81 ways that you and I enjoy this wonderful
pastime: RADIO... covering from the extra low frequency kilometric waves
to the microwaves just touching light... and we even do talk about light
communications from time to time too, as they are becoming popular among
radio amateurs... Well, here we go again with the sad news of a terrible
hurricane making landfall and causing loss of life and doing huge
damages to people's homes... and once again amateur radio operators
volunteered to provide much needed emergency communications. The two
most recent tropical hurricanes that hit Mexico and Central America
provided an excellent example of how amateur radio communications is
able to provide much needed links to deliver aid to the badly hit areas
immediately after the storm is over... Amateur radio operator’s e went
to places that were assigned to each of them in case of a natural
disaster, and they immediately installed their stations, ready to
provide links with shelters, dams, hospitals and local government agencies.
Among the many lessons learned during each hurricane emergency there are
two that I wish to share with you mis amigos, listeners of Dxers
Unlimited that are also amateur radio operators... I'll go trough them
later as the program's weekend edition continues in a few seconds...
I am Arnie Coro in Havana, and this station you are now listening to is
Radio Havana Cuba, on the air since 1961!!!
.......
Si amigos, you are listening to the weekend edition of your favorite
radio hobby program, and I want to thank the many listeners that have
sent e-mail messages, letters and postcards not only reporting reception
of the show, but also providing me with very valuable comments and ideas
on how to improve the program...Now, some information about RHC
transmitter tests that will soon be on the air on the Tropical Band
frequency of 5055, again the frequency 5055 kilohertz, and.. Again the
test frequency is going to be 5055 kilohertz and we may also be testing
on another lower frequency on that same 60 meters Tropical Broadcast
Band soon.
Now back to item one: Every time that there is a hurricane related
emergency, amateur radio station operators learn more on how to handle
the different situations. During the recent most recent storms, one of
the lessons learned was that we all needed to have more storage
batteries available at the sites where the stations were operating, and
that those storage batteries must be fully tested, charged, and then
discharged and charged again, to be really sure that they will be in
perfect state, so as to provide the ampere hours for which they were
designed.... At CO2KK my ham radio station that is used as the
International Amateur Radio Union Emergency Coordination Station for
AREA C of ITU Region II, one of my two 12 volts car batteries that I
thought was in a very healthy state, proved to be in bad shape, and I
later found out that one the cells was in a short circuit condition,
something that reduced the voltage dramatically and made the accumulator
useless for all practical purposes. CO2KK's batteries at charged during
the emergency at a nearby facility that has a brand new 25 kilovolt
ampere diesel generator...But that facility is located about three
blocks away from my home, and as everyone knows, you can't go out in the
middle of the hurricane... so if your batteries fail while the heavy
winds and rain are blasting your place, then your emergency station
simply goes off the air, until the storm is over and you can walk with
the batteries to the place where the generator is located !!!
LESSON Number two: Prepare reserve indoor antennas for your specific
location, and do remember that if properly built and installed, an
indoor antenna can keep your emergency station on the air even at the
peak of the storm, when very probably your main antenna system sustains
heavy damage due to the fierce winds of the hurricane or what may also
happen, that somehow the heavy rainfall is so powerful as to force water
into the coaxial connectors and render your antenna system useless. And
of course this takes us to LESSON Number three: it is vitally important
to protect all antenna connections to the coaxial cable downleads with
the best possible sealing, in order to prevent the dramatic loss of
communications when they are most needed. My elder son , Arnie Jr. radio
amateur CO2KK, specializes in providing protection against the weather
to antenna systems, and I have witnessed that after seven years exposure
to the severe tropical weather conditions of Cuba, a shortened dipole
antenna for the 80 meters band connection to the coaxial cable was in
like new condition when I disassembled it after taking the antenna down
for what I expected to be a total replacement, which of course, was not
needed at all due to the excellent protection provided when it was
installed...
The Atlantic Hurricane Season is still in progress, and we have the
whole of October and November to go, so for those of you that are
located in areas where tropical storms may make landfall, now it's good
time to review your emergency communications systems capability and
prepare for any possible future event...
Let's hope you won't ever need to use your ham radio gear for that type
of service to the community, but amigos, it's better, it's always better
to be prepared....
.....
This is the weekend edition of Dxers Unlimited... and here is good
news... we have just passed the Autumn Equinox, but unfortunately, the
Sun has remained spotless for an extremely long period... day after day
with solar flux below 70 units and no sunspots have required scientists
to readjust their forecasts for the minimum of cycle 23 several times
now.... Even though solar activity is at extremely low levels, HF DX
enthusiast continue to enjoy openings even with sunspot counts of ZERO
day in and day out.... you may also catch openings on the 40, 30 and 20
meters amateur bands, but, 17, 15, 12 and 10 meters remained closed for
DX most of the time due to the extremely low ionization caused by the
extremely low solar activity we are seen these days
And now that I talk about 12 and 10 meters, let me say that we have
already said good-bye to the F2 propagation on 12 and 10 meters until
the next solar cycle generates enough activity to help the two higher
frequency HF bands to make a comeback. No, I am not saying that 12 and
10 meters won't open up occasionally, what I'm trying to say is that due
to the very low average solar activity that will still prevail for the
next several months, chances that 12 and 10 meters will open up for DX
via the F2 layer are extremely low !!!
Item six: Our popular antenna topics section will be devoted today to
review some of my recent experiments with a unique antenna design, that
has among its relevant characteristics a very low profile, while still
retaining excellent low take off angle , essential for working DX... I
have been doing more experiments with the FOUR Ls antenna system, and
the more I test it the more I like it amigos... This experimental low
profile antenna is now into a much more advanced stage of development,
and much low budget low power AM broadcast stations are looking at the
FOUR L as a possible alternative to replace the existing tall steel
towers that they need to use. My experimental FOUR L antenna system for
the 10 meters band was followed by an identical set up for 20 meters,
and I'll keep you up to date with the results of the new 20 meters band
FOUR L antenna, when propagation picks up and the band is in better
shape. So far the 4 Ls antenna has shown excellent low take off angle,
and what is really amazing is that the antenna height above the ground
system is just two and a half meters, that is a bit less than eight
feet, while a regular 20 meters band quarter wave vertical is five
meters or 16 feet high... For those of you not familiar with the FOUR L,
it consists of four pararell connected inverted L antennas that are fed
at the starpoint using an impedance matching network. The antennas must
be provided with a very good counterpoise or ground system, and
experimental work with elevated radials seems to be a very attractive
thing to do, as with just a few elevated radials, the FOUR L low profile
antenna may provide the low take off angle required for working DX
Si amigos, yes my friends, the FOUR L experimental antenna is looking
like a very promising development for those of us that cannot install
tall masts or towers and still want to work DX on the 160, 80 and 40
meters bands...and even for those that require low profile antennas to
operate on the 30, 20, 17, 15, 12 and 10 meters amateur bands.
And now just before going QRT, here is Arnie Coro exclusive and not
copyrighted HF plus low band VHF propagation update and forecast...
Solar activity is now at very, very low level, with solar flux around 67
to 70 units, and according to the latest optical observations of the Sun
there is a very small sunspot, a really small sunspot in sight... a turn
for the better after many, many days without a single sunspot. Trans
equatorial VHF propagation on the SIX METERS band from Argentina, Chile
and Brazil to the Caribbean and the southern United States should be
happening now on a daily basis, usually after local sunset... AM
broadcast band and Tropical Band dxers will enjoy excellent propagation
conditions for the next two weeks or so due to the low solar activity
combined with geomagnetic disturbances that distort low frequency
propagation patterns especially at high latitudes, making possible to
hear some unusual AM broadcast band DX... I. hope to have you all
listening at the mid week edition of Dxers Unlimited amigos, and don't
forget to set aside a little of your valuable time to send me your
comments about the program, with any suggestions of topics to deal with,
or ideas on how to improve this show that comes you with love from
Havana twice weekly. My e-mail address is arnie@xxxxxx, and the postal
address is Arnie Coro, Radio Havana Cuba, and Havana, Cuba...
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