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Re: [HCDX] From Arnie Coro Host of Dxers Unlimited
Radio Havana Cuba
Dxers Unlimited's weekend edition for 23-24 August 2008
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados ! You are most welcome to the weekend edition
of Dxers Unlimited, coming to you from Havana, via short wave and also
via the world wide web audio feed from http://rhc.cu in English from 05
to 07 UTC.
I am Arnie Coro, radio amateur CO2KK, your host here in the sunny
capital city of Cuba where the temperature at noon Friday was about 32
By the way at the time that I was recording the show, early morning
Saturday the temperature was a bit cooler 24 degrees Celsius with the
relative humidity at 70 percent... and yes , after the side effects of
Tropical Storm Fay felt here on the western part of Cuba, once again we
are enjoying a beautifully blue sky due to the presence of a high
pressure ridge that may produce a nice tropospheric ducting opening at
any time now.
As a matter of fact, this Saturday was ideal to go to the beach and also
to generate a good tropo duct opening !!!
Now here is item one: One of the most popular ways of enjoying the radio
hobby is, without any doubts,AM medium wave broadcast band Dxing, that
according to the e-mail messages, postcards and letters received here,
generates a lot of interest among listeners of Dxers Unlimited around
Receivers and antennas especially designed for AM medium wave broadcast
band Dxing will make a big difference on the results that you can
achieve, while locations with very low noise levels and far away from
high power stations are described by the avid AM Band Dxers as the ideal
places where to go for a Dxexpedition.
With solar activity at an all time low for the past 11 years, we may be
able to enjoy a very nice upcoming autumn equinox AM broadcast band DX
More about the extremely low solar activity that has prevailed since
October of last year...
A detailed account of the way that the solar cycle has behaved in a few
seconds, when the weekend edition of Dxers Unlimited will continue. I am
Arnie Coro in Havana.
You are listening to Radio Havana Cuba, the name of the show is Dxers
Unlimited , and here now is a detailed account of the solar statistics
that clearly show that the Sun has gone trough two minimums.
The month of October of 2007 registered an extremely low monthly sunspot
average of 0,9, that was followed by a very slightly higher figure of
1.7 in November, then during December of last year activity increased to
10.1 , only to take a dip to 3.8 during January, continue the downward
turn in February to 2.1, and then March data shows a montly sunspot
average of 9.3.
Some scientists thought that solar cycle 24 was starting , but they were
wrong... April and May of 2008 average monthly sunspot count registered
the same figure of 2.9, June was just slightly more active at 3.1 and
then July brought the lowest monthly sunspot average of the whole cycle,
just 0.5, that meaning that for practically 31 consecutive days solar
optical observers saw a totally blank solar disc....
And to bring to an end this lenghty but very important statistical
analysis, so far, during 22 days of the month of August, only a very
small cycle 23 sunspot was seen . In total agreement with the zero
sunspot count that has prevailed during August, the microwave solar flux
at 10.7 centimeters way length has stayed at rock bottom levels , with
an average very near the minimum ever registered of 64 units.
Now, after you have patiently heard those terribly low numbers, here is
the analysis of what they may mean for the low frequencies DX
enthusiasts, a crowd that includes operators of automatic low frequency
beacons, listeners to the natural radio emissions of Planet Earth that
include the often heard but not very well known whistlers, Long Wave AM
broadcast band Dxers, the radio amateurs that are operating on the two
thousand and two hundred meters band, non directional aviation beacon Dx
hunters , the new group of radio amateurs that are operating on a
segment of the old Marine 500 kiloHertz band, and those that are not yet
allowed to transmit on the 600 meters band, but that as I am doing are
constantly monitoring that new ham band in order to learn more about its
unique daytime propagation characteristics.
But if you add the people devoted to the above mentioned ways of
enjoying the radio hobby, they are no match to the hundreds of thousands
of persons around the world that in one way or the other have a good
time trying to pick up DX stations on the AM medium wave broadcast band,
where practically every nation in the world has at least one station
If the present extended period of very low solar activity continues
during the months of September and October then AM medium wave broadcast
band Dxers will enjoy a super DX season, because of the very low
ionospheric absorption that will prevail during the upcoming autumn
equinoctial period, that should be starting in about two weeks and
extend at least until mid October.
Si amigos, yes my friends, oui mes amis, AM broadcast band Dxing ,
according to my propagation forecast, is going to be really amazing, and
the only thing that could spoil this autumn equinox DX season will be a
sudden , abrupt and so far unexpected increase in solar activity.
Get ready for what is going to be possibly the best AM band and Long
Wave broadcast bands DX season in years to come... and stay tuned to
this program , because our technical topics section for today will
provide you with several nice tips for low frequency Dxing, in the range
from 10 kiloHertz all the way up to 2 megaHertz, because, yes... the 160
meters amateur band is also going to be excellent for Dxing during the
upcoming autumn equinox...
You are listening to Radio Havana Cuba, the name of the show Dxers
Unlimited, and here is now our technical topics section, that is
competing in popularity with our HF and low band VHF propagation updates
and forecasts and even with ¨¨ La numero uno¨¨ the most requested and
popular section of this program ¨¨ ASK ARNIE¨¨
So get ready to copy, here are several really practical and easy to
follow tips for Dxing the low frequency spectrum from 10 kiloHertz all
the way up to the end of the AM broadcast band, and even to the top of
the amateur 160 meter band amigos !!!
Tip number one: Check your noise level, and try to find which are the
radiofrequency noise generators that sorround your listening post. I
remember many years ago when I first visited a point to point short wave
communications system receiving station, that all the lamps they used
were incandescent lamp bulbs... when I asked the Chief Engineer at the
Prensa Latina news agency HF receiving station out in the countryside
near Cuatro Caminos a small village southeast of Havana , he told me
that fluorescent lamps were prohibited at the receiving site, because
they generate a lot of Radio Frequency wide band noise.
He also added that the power line that provided electricity for the
receiving site came by means of an underground three phase high voltage
cable that was more than two kilometers long, so that no overhead power
lines were within the vecinity of the antennas.
Of course that I am aware that the average low frequency Dxer cannot
enjoy the benefits of such a specially built site, but you can certainly
check carefully and find out, for example, how each of your home´s
electrical distribution systems contributes to your low frequency bands
noise level. Just by going to the circuit breakers at the entrance and
disconnecting them one at a time, you may be able to find, for example
that the breaker providing power to the living room , when disconnected,
makes low frequency reception much better.... Something that later was
traced to a fish water tank air pump... because the nice tropical fish
aquarium was located right in the living room of the house. This was a
real life experience for a Dxers Unlimited listener that sent a question
to the ASK ARNIE section of the program asking how he could find out the
source of a ticking sound that was making his reception on the low
frequency bands very difficult , and even up to 10 megaHertz very
annoying, because of a repetitive tick , that in this particular case
was caused by the fish tank air pump !!!
By switching the circuit breakers one at a time, you may also find out
that the older computer in the kids room , the one still running with a
big CRT picture tube monitor is a terrible noise generator... a problem
that can be solved by changing to an LCD monitor, but be aware , that it
MUST be an LCD monitor,because the PLASMA displays are even worse noise
generators than the old picture tubes used by the early computer monitors.
Next tip: This will require a small AM broadcast band receiver and a
pair of good quality headphones...The next step is to go all around your
home with all the lights ON, and put the small portable radio near each
lamp, while it is tuned to an empty frequency at the low end of the AM
broadcast band. As many Dxers Unlimited listeners have learned in the
past, because this is not the first time that I explain this procedure
in the program, well, this easy technique will quickly point at the
With the compact fluorescent light bulbs now in use all around the world
to save energy and reduce CO2 pollution , this is particularly important
, and let me add amigos, that ¨¨ Not all compact fluorescent light bulbs
are created equal¨¨ If you realize what I mean... The fact is that all
radio hobby enthusiasts must learn which are the CFL´s compact
fluorescent lamps that make less radio frequency noise, and to your
advantage , there is the coincidence that the ones that generate less
noise are usually the highest quality CFL´s , although I must add that
they are also usually the most expensive too..
The next tip is also related to the way your home is illuminated, and it
may be considered by some really dyed in the wool low frequency Dxers an
essential step if you really want to reduce the local noise level... Try
to start installing Light Emitting Diode Lamps... but be very careful,
because some commercially built LED lamps are terrible noise generators
The reason that some of those super energy saver LED lamps generate
noise, is that they used a switching mode power supply that sends down
the drain any advantage that the low voltage light emitting diodes offer
in contrast to the compact fluorescent lamps.
So, before buying LED light bulbs that can be plugged directly to
replace incandescent or CFL bulbs, check that they are not using a
switched mode power supply...
Some radio amateurs that have acquired all along their ham radio careers
the ability to homebrew equipment, have built very nice arrays of white
light emitting diodes that are powered from linear power supplies and so
provide excellent illumination, no flicker , and no noise...
Just recently, a friend that visited here gave me several white light
emitting diodes, and I decided to use them for making a lamp that is now
located at my listening post and amateur radio station operating
position, with excellent results... Although the Compact 15 watt
fluorescent lamp that I used there was not very noisy, my sensitive
broadcast band DX receiver could pick up the background noise that could
only be suppressed by switching OFF the CFL lamp.
With the new white LED array of six diodes, the noise level is ZERO !!!
Well amigos, the topic of low frequency Dxing is so fascinating that it
seems like it would require more time alloted to it during upcoming
Dxers Unlimited programs.. You may want to provide me with feedback
about today´s tips for reducing the RF noise level at your home , and
also tell me if you have any question related to finding noise sources
and trying to wipe them out !!!
Si amigos, yes my friends, zero sunspots one day after the other, an
amazingly low monthly sunspot count for July, and August is moving along
the same line, but despite the minimum solar activity, radio amateurs
continue to enjoy the hobby by traveling to remote DX locations and
usually combining nice vacations with giving to fellow hams the
opportunity to work new and usually rare prefixes...
Stay here until the end of the program because as ALWAYS when I am in
Havana, at the end of the show, have your tape recorder ready for Arnie
Coro's Dxers Unlimited's HF plus 6 meters propagation update and
forecast , a practical guide for optimizing the enjoyment of your radio
hobby , be it short wave listening or amateur radio, or any other of the
more than 83 ways we can enjoy radio !!!
Here are is now one of the most recent Dx expeditions soon to be on the
The Principality of Monaco, with the ITU Prefix 3A will be on the air
thanks to Patrice, a french amateur that will operate his Dxpedition
with the callsign 3A stroke F5RBB starting on the first of September and
for 10 days. Patrice will be on the air on 40, 20, 15 and 10 meters and
his QSL information is via his home call via direct or trough the French
He will provide a nice opportunity for newcomers to the hobby to work
Monaco for the first time.
And now as always at the end of the program here is our HF and low band
VHF propagation update and forecast. Solar activity expected to continue
at baseline levels with solar flux not higher than 70, expect noise
levels on the low frequencies up to 10 megaHertz to continue high during
the late afternoon and early evening local time ,due to summer
Best time for long haul DX continues to be starting at around 2 hours
before sunrise and just a brief period after sunrise. See you all at the
mid week edition of the program amigos, and don´t forget to send your
signal reports and comments to inforhc at enet dot cu or Via Air mail to
Arnie Coro, Radio Havana Cuba, Havana . Cuba
Posted By Arnaldo Coro to Dxers Unlimited
at 8/23/2008 10:40:00 PM
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