Radio Habana Cuba

Dxers Unlimited

Dxers Unlimited's mid week for 18-19 January 2005

By Arnie Coro

radio amateur CO2KK



Hi amigos radioaficionados , welcome to the mid week edition of Dxers
Unlimited on the air at the time that Planet Earth is experiencing a
geomagnetic storm caused by the recent extraordinary flare activity
happening at solar active

region 720. Auroral propagation is expected to happen again this
evening, and be prepared for more possible short wave propagation
disturbances.

The effective sunspot number went up to 100, the highest in several
months and that opened up the 10 and 12 meter bands for the enjoyment of
amateur radio operators worldwide.

10 meters, covering from 28 to 29.7 megaHertz is one of the most
interesting band allocated worldwide to the amateur radio service, and
during the declining phase of the solar cycle only opens up when periods
of high solar activity as the present one, catch everyone by surprise.

So follow your friend's Arnie Coro's advice and monitor the 15 , 12 and
10 meter amateur bands for excellent DX during the next three to five
days !!!

Item two: Catching up with so many e-mail messages, postcards and
letters always waiting to be answer is a part of my job as Dxers
Unlimited's host that I enjoy more. You can't imagine what a rewarding
experience it is, and how much I learn from listener's questions and
comments amigos !

Recently I was encouraged by several listeners to do a compilation of my
YOU HAVE QUESTIONS section of the show, in order to revie the
possibility of editing them into a printed paper book, and you know
something... reviewing so many scripts was a time consuming but at the
same time very interesting job... So, YES, I'll do it amigos Michael,
Mark, Terry, Louis, Mara and Teddy, and you six will be the first

recipients of VOLUME ONE of YOU HAVE QUESTIONS at Dxers
Unlimited...Thanks for the great idea amigos !!!

Item three: Cuban TV networks continue to expand and upgrade

obsolete transmitters... so TV DXERS in North America, the Caribbean and
Central America, as well as those of you in the northern part of South
America, be on the lookout for much better signals from CUBAVISION ,
TELEREBELDE AND CANAL EDUCATIVO, the three Cuban TV networks that
operate their transmitters on the VHF Low TV band channels two to six.

CANAL EDUCATIVO's Havana VHF transmitter is broadcating on TV channel 4,
using the NTSC-M standard, and it's delivering a very high quality
signal to three Cuban provinces, the City of Havana,  the province of
Havana, and part of Pinar del Rio. Havana's TeleRebelde channel 2 TV
transmitter is also a brand new one, as well as  CUBAVISION channel 6.
The three stations are broadcasting from the TELEVILLA site west of the
capital, and CANAL EDUCATIVO DOS the second educational TV network is
also broadcasting from the same site using UHF channel 15 with a very
nice high gain antenna at the top or Televilla's tower, that was
installed way back in 1956.

But this is not the nation's tallest TV tower... Televilla is the second
highest one, with Camaguey's TV broadcast center tower been the nation's
highest man made structure, after Canal Educativo's UHF antenna was
installed at the top, reaching the 203 meters high mark. By the way for
those of you that enjoy learning about TV broadcast towers, 200 meters
is considered by structural engineers the highest possible towers that
can be installed in Cuba with a long life expectancy, as higher towers
can't take the fierce force of hurricanes , even when the storms don't
strike directly into the area where they are located..

More about Cuba's ongoing radio and TV development programin an upcoming
edition of Dxers Unlimited amigos !!!

Stay tuned for more radio hobby related information, and don't forget to
set aside a little time to send me your signal reports and comments ,
that help me improve Dxers Unlimited for your listening enjoyment. send
mail to arnie@rhc.cu

Jose Costa Pupo is my sound engineer and producer... I am Arnie  Coro in
Havana, back in a few seconds !!!

....

Si amigos ! You are listening to Dxers Unlimited's mid week edition,
coming to you when short wave reception conditions are surely difficult
due to the effects of a geomagnetic storm. At higher latitudes, say
above 40 degrees North, receiving short wave stations is going to  be
difficult to say the least, during the next two to three days...

Now item four: A new revolutionary broadband over the power lines
INTERNET connection capability now under test will send the current BPL
or Broadband Over the Power Lines systems using frequencies from 500
kiloHertz to 80 megaHertz into total obsolescence... Existing BPL
systems cause a lot of harmful interference to all radio spectrum users
from below the AM broadcast band well into the VHF region due to
harmonics, and that's the reason several national telecommunications
administrations have decided to ban, actually to remove from service the
use of BPL systems using the current technology. The NEW MICROWAVE BPL
will not generate so many problems to other users of the radio frequency
spectrum according to the engineers that created it ... Now, it's

going to be a wait and see process, in order to assess the feasibility
and cost of the MICROWAVE BPL. Anyway, for us , users of the HF and VHF
spectrums, so badly interfered by the current BPL existing systems, the
new MICROWAVE SYSTEM certainly means a relief from what we were
expecting to happen if the old BPL developed at a fast pace...

.......

This is Radio Havana Cuba, the name of the show is Dxers Unlimited and
here is item five:  Radio frequency chokes  are inductances that isolate
radio frequency currents from certain areas of a radio circuit. Radio
frequency choke design is both an art and science, as they require to
meet certain very demanding parameters if you want them to work
properly. Any amateur radio operator that has received the great
surprise of a radio frequency choke burning up as  a high power
amplifier is tuned up on a certain band, knows very well how important
proper radio frequency choke design is for good and reliable HF power
amplifiers operation.

But RF chokes are also important for receivers, and regenerative
receivers are no exception, that's why answering a question by listener
Thomas in Hamilton, Ontario , Canada, I will provide here today
information about an easy to build radio frequency choke that works very
well with vacuum tube regenerative radios, although it does have one
drawback, and that's its size.

But as glowbugs, or vacuum tube equipment built by homebrewers seldom
qualify as miniature radios, the big ,but efficient and easy to make at
home RF choke is a welcome addition to your bag of electronic and radio
tricks..

Here is how to build your own RF choke for regenerative receivers
detector's plate circuit. Find a 100 millimeters or 4 inch length of 10
to 12 millimeters, about a half inch, PVC thick wall pipe, or better
yet, look for a solid piece of high impact poliethylene rod. Old timers
simply used a round wooden dowel coated with paraffin and amigos, their
radios worked quite well indeed !!

Ah, before I forget you can also use polystyrene rod too.

Then find number 28 or number 26 enameled wire, and if you are a lucky
person, may you can find our granfather's favorite for winding chokes,
the DCC or double cotton covered wire that is as rare as the extinct
DODO bird...

Wind 300 hundred close spaced turns on the rod, and VOILA !!! You are
the proud owner of a nice , and highly effective radio frequency choke
for the plate circuit of your regenerative detector.

You can wind 100 more turns on a longer rod, if you want to use your
radio below the AM broadcast band, but in that case my advice is to just
try to buy a commercial 2.5 millHenries RF choke,although they are also
becoming a collectors item !!

And that was TIPS AND TECHNIQUES here at Dxers Unlimited's mid week
edition....

.....

High speed Morse CW transmission are bringing in some interesting
results for meteor scatter propagation enthusiasts for a long time now,
but much more sophisticated systems using computer programs that fully
exploit the capacity of high speed microprocessors are quickly
displacing high speed Morse CW as the standard mode of communicating via
meteor scatter propagation. As a matter of fact it is interesting to
learn that some professional communications system still make use of
meteor scatter to send signals from remote sites via automatic
transmitters . That's the case of snow avalanche detection monitors and
floating ocean going drift or anchored bouys that send data to command
centers using the ionized trails left by random meteors .

Si amigos, radio is fascinating, and there are many, many ways that you
and I may have a good time playing with our radios... as a matter of
fact there are 78 plus ways of enjoying this hobby, from AM broadcast
band Dxing with your old and now classic bedside clock radio, that could
prove quite a challenge to say the least, to operating your own amateur
radio station

using digital Earth orbiting satellites... ENjoy radio also by listening
to short wave broadcasts and support your favorite short wave station by
sending in regular listeners reports... For Radio Havana Cuba, the
station you are listening to, it's a great pleasure to receive your
signal reports and comments about our programs, send them directly to
me: arnie@rhc.cu, or VIA AIR MAIL ,send a postcard to

Arnie Coro, Radio Havana Cuba, Havana. Cuba

And now as always at the end of the show, here is our exclusive and not
copyrighted HF plus low band VHF propagation update and forecast...

Geomagnetic storms back to back, in progress, sending the daily A index,
the planetary geomagnetic disturbance indicator way above 40 units...
The sunspot count also rather high , and the all important effective
sunspot number reaching the magic 100 mark , bringing in nice openings
on the 12 and 10 meters amateur bands... HF propagation  is presently
poor at higher latitudes due to the increased absorption. Expect very
interesting propagation on the AM medium wave band if you live at a
latitude of 40 degrees North of higher... See you all at the weekend
edition of the show amigos !!!