Radio Havana Cuba
Dxers Unlimited
Dxers Unlimited's weekend edition for 28-29 January 2006
By Arnie Coro
Radio amateur CO2KK

Hi amigos radioaficionados around the world and in space too !!! Welcome to
the weekend edition of your favorite radio hobby program, coming to you from
Havana. I am Arnie Coro radio amateur CO2KK and here is item one of today's
show. Solar activity expected to take another nose dive for at least three
or four days, but heliosysmic techniques are showing now a medium sized
sunspot on the farside of the Sun that may soon turn into Earth's view. So,
be prepared for a few days of a very quiet Sun, that will give us excellent
low frequency propagation. Item two: E-mail messages, letters, postcards,
phone calls to station and fax messages keep me busy all along the week,
searching for answers to the questions sent in by Dxers Unlimited's
listeners and keeping track of HF propagation conditions for preparing the
propagation forecasts that are so popular also takes a lot of time, but all
the efforts are fully rewarded with so many nice compliments about my work
that come from Dxers Unlimited's fans all around thw world. Thank you amigos
and don't worry, the year 2006 will see more improvements on our show, so
that you and I may enjoy this wonderful hobby still more than we do now !!!
Item three: Sorry dear digitally minded radio amateur operators, but my 486
computer sound card broke down, and that's why CO2KK is no longer seen on
the screens of PSK31 mode operators. All efforts made to find an ISA bus
sound card have failed so far, but I keep trying by keeping the request at
our Marianao Radio Club Parts Exchange, that my good friend Jorge Jordan
CO2JJ runs every Sunday on the long range 145.110 megaHertz two meters band
repeater. Jorge receives both requests and offers of parts and equipment
from radio amateurs all over Cuba, and then he broadcasts them on the
repeater Sunday morning. The parts exchange works wonderfully, and has
helped many Cuban radio amateurs to fix equipment, dispose of parts and
radios no longer in use that then find a new home, and above all, it brings
in a lot of goodwill among the radio amateur community .
Item four will follow in a few seconds, when Dxers Unlimited's weekend
edition continues. Stay tuned, I am Arnie Coro in Havana.

..
Si amigos, yes my friends. many short wave listeners and radio amateurs seem
to enjoy collecting equipment, but not only radios, but also electronic
components, antenna insulators, coaxial cables. you name it. and things
start to use up a lot of space. that's why the Marianao Radio Club's
executives idea of promoting the exchange of radio hobby related items has
become so popular here. For example, I happen to have 30 pin obsolete memory
modules for 286 and 386 machines that are still used with the MS-DOS
operating system by many Cuban hams. so I talk to Jorge CO2JJ, and tell him
that eight of those 30 pins memories are available to anyone needing them.
Jorge puts my offer into the list, and last Sunday, the offer was made
public over the 2 meter band repeater. Less than five minutes later, I
received a call from a newcomer to the radio hobby, a young amateur that had
just assembled from recycled components a 386 machine running at 25
megaHertz clock frequency. He had only 2 megabytes of RAM, but his
motherboard could take 6 more modules. Monday morning , after he came back
from work, he dropped by to pick up the eight modules that I had in storage
here at my shack. Now his machine runs much better, and Roxana, my wife is
very happy as at least something of what's clobbering the garage went away
!!! Cuban radio amateurs help each other very much, and whenever possible
parts are exchanged , traded or just given away at no cost, or at a fraction
of what they may cost.
Item five: Many radio amateurs are getting ready for all the upcoming
winter contests, and all will have to deal with very low solar activity,
something that may prove particularly attractive to operators capable of
using the 160 and 80 meter bands. PLUS, 40 meters is going to be an
excellent contest band too, but efforts must be made not to extend the
operation during single side band contests below 7025 kiloHertz, to avoid
interfering with CW stations that make regular use of that band segment.
Item six: SUITSAT, a unique amateur radio satellite will soon be launched
from the International Space Station. SUITSAT is a very unusual satellite,
consisting on a no longer useable Russian cosmonauts space suit, to which
equipment was fitted to make it work as a ham radio satellite for a few days
because the power will come from non rechargeable batteries. It will be
"hand launched' from the International Space Station and I am pretty sure
that it will generate a lot of interest among many of the world's radio
amateur operators !!!
Keep listening to news bulletins, for the exact launch date and time of
SUITSAT satellite !!!
...

ASK ARNIE, la numero uno, the number one most popular section of this
program is now on the air. Answering a question sent in by listeners from
New Zealand, Australia, Japan, India and Canada. They all want to know more
about the very short vertical dipole antenna for the 20 meters amateur band
recently described here, as all of them would like to install that type of
antenna system, in order to be able to enjoy HF operation. Listener Harold
in Australia tells me in his e-mail that for the past three years he has
only operated on two meters, because there is no space at his QTH to install
an HF antenna. something that seems to be very common among apartment
dwellers. My perception is that more information must be made available on
amateur radio publications about MAGNETIC LOOPS, because they are even
easier to install and use less space than the ultra-compact vertical
dipoles. But, let me, anyway answer the question about the way that this
twenty , seventeen or fifteen meters band compact antenna was designed. At
the present phase of the solar cycle your best option will be to build the
twenty meters band antenna, as it is the band most likely to be open for DX
during the next few months. Now, listen carefully. The first characteristic
or my new KK-COMP DASH 3 antenna is the use of a large diameter radiating
element. in this case made of 50 or 75 millimeters diameter tubing. The
optimum choice will be COPPER TUBING, although you may use aluminum that is
a lot lighter in weight. The two loading coils are wound using number eight
copper wire, and if possible the coil forms should be made of TEFLON for
minimizing losses, but my prototype DASH 3 uses PVC pipe sections of the
type used for high water pressure, that fit perfectly into the copper tubes
that form the two legs of the dipole. The capacity hats are made of copper
plate in my protype for the powerful reason I happened to have it available,
but you can make yours using aluminum and the antenna performance will be
exactly the same.
In my latest design, the twenty meters band vertical dipole lower end is
kept at a distance of two meters from the rooftop, and the coaxial cable
feedline coming out of the center of the antenna extends away from the
dipole at a 90 degrees angle for a distance of 5 meters in order to avoid
distortion of the vertical antenna's radiation pattern.
This is a medium to low angle radiating system, and despite the fact that it
is only 4 meters overall length, its performance and bandwidth are excellent
when compared with a full size 10 meters long half wave vertical dipole.
Tuning the antenna to resonance to the desired operating frequency took some
time, playing with the loading coils , until the antenna resonated at 14.15
megaHertz, giving me the opportunity to work CW, digital modes and single
side band modes between 14.0 and 14.350. that is all across the 20 meters
band.
AND, last but not least amigos, the compact vertical loaded dipole has a
very nice look, so nice in fact, that several neighbors have asked if I am
now also into modern abstract art sculptures !!!
If you want to know more about these compact low profile, very small
footprint antennas that don't require the use of ground radials, something
that makes possible installing the antenna in very tight
quarters, just drop me an e-mail to arnie@rhc.cu, or VIA AIR MAIL send a
post card to Arnie Coro, Radio Havana Cuba, Havana , Cuba.
...
This is Radio Havana Cuba, the name of the show is Dxers Unlimited, and it's on the air twice weekly for the enjoyment of radio hobby enthusiasts around the world. At present we are also offering an Internet streaming audio option on the 05 to 07 UTC English language broadcast. Connect to http://www.radiohc.cu and click on the audio icon. We are also providing the scripts of the program to the ODXA, Yahoo groups mail distribution list, and at our website http://www.radiohc.cu,... Now here is item seven to today's program. our listening tips section of Dxers Unlimited, today devoted to medium wave AM broadcast band listeners.. At the request of many AM band Dxers that want to pick up more Cuban stations, here are several frequencies and locations of rather easily heard Cuban AM band stations. on frequency 1220 kiloHertz, Radio Caribe, from the Isle of Youth is now on the air with its new 5 kiloWatt high modulation efficiency Chinese transmitter. capable of modulating up to 125 percent of the positive modulation peak. The station is sharing the same tower with the Isle of Youth Radio Progreso Relay on 730 kiloHertz, using a Cuban designed and built antenna diplexer for the folded monopole vertical that has proven to provide a very high radiation efficiency on both frequencies. So if you want to add not one but two new ones to your AM broadcast band log , look for Radio Caribe on 1220 kiloHertz and Radio Progreso's relay on 730 kiloHertz. Listeners in Central America, the Caribbean, the United States of America and Canada will surely be able to pick up these two new transmitters and can ask for confirmation to Radio Caribe , Isla de la Juventud, Cuba,for the 1220 frequency and to Radio Progreso Po Box 3042 Havana, Zip Code 10300 to the attention of Chief Engineer Jose A. Fuentes.