Dxers Unlimited
Dxers Unlimited's weekend edition 27-28 December 2003

By Arnie Coro

Radio amateur CO2KK




Hi mis amigos radioaficionados around the world and in space... Nice to have you listening to the
weekend edition of this twice weekly program devoted to our wonderful hobby, yours and mine: RADIO..
and here is item one: Two big sunspots regions... one visible, the other one now transiting the side
of the Sun that we don't see, but that we can now explore with the help of ultrasophisticated
HELIOSISMIC TECHNOLOGY... So, Sunspot active region 528 is now very clearly visible and by the New
Year we may see yet another big sunspot region reaching the visible side of the Sun... By the way ,
the solar flux is hovering around 130 to 140 units, and we will be experiencing quite stable HF
propagation conditions during the next five to seven days...IF, region 528 doesn't become too active
generating solar flares. For amateur radio operators around the world enjoying the end of the year
holidays, the good news is that present solar activity levels allow for quite nice openings even on
the 10 meter band. The openings will not be fantastic as when the solar flux is above 200, but they
will certainly be there for all of us to enjoy. ITEM TWO: DRM , Digital Radio Mondiale test
transmissions continue to puzzle radio engineers around the world, as they are certainly using much
more actual bandwidth than what was predicted by those who created the digital transmission
standard... This may be related to non linearity of the transmitters that are in use for the DRM
tests, and among them the best example of excessive bandwidth is the 6010 kiloHertz DRM broadcasts
coming from Sackville , Canada and spreading all along a wide area of the 49 meters international
short wave broadcast band... As many Radio Havana Cuba listeners have told us in their e-mail
messages, the noise coming from the DRM tests on 6010 kiloHertz is certainly making reception of our
6000 kiloHertz signals to Eastern North America rather difficult. Let's hope that ITU monitoring
stations become aware of the problem and will report the problem to the corresponding
telecommunications administrations.

Item three: Microwatts, yes thousands of a WATT transmitters can be heard at long distances via
ionospheric propagation when conditions are right, and the signals are transmitted on the optimum
working frequencies... Recent experiments using ultra low power amateur transmitters on the 10
megaHertz or 30 meters amateur band have shown that beacon stations operating below the one
milliWatt level can be picked up by standard antennas and receivers , especially if the receiver is
connected to a computer and software combination especially designed to detect very low level
signals within a very restricted bandwidth. Low frequency band experimenters are using digital
signal processing technology on an everyday basis and are achieving fantastic results on the 136
kiloHerts or two point two kilometers wavelength band... ITEM THREE: Our technical topics section
today will be presenting information about low cost approaches to amateur radio, as I do insist that
ham radio need not be considered an expensive hobby at all... especially if you enjoy shopping
around or homebrewing your equipment... Then ITEM FOUR will be our very popular you have questions
and Arnie tries to answer them section of Dxers Unlimited, and as always when I am in town, at the
end of the program our exclusive and not copyrighted HF plus low band VHF when it applies,
propagation update and forecast... Standby for a few seconds, I'll be back on the air and on the web
with the weekend edition of Dxers Unlimited after a brief musical interval.

........

You are listening to Radio Havana Cuba, the name of the show is Dxers Unlimited, I do hope that you
all are in good health and enjoying the holidays amigos... And now here is a bit more about item
two: Several freeware programs that are now available will allow your receiver plus computer
combination to be used as an ultrasophisticated space age detector of extremely weak signals. The
programs are very similar from the ones used by the space agencies to keep in touch with vehicles
far beyond the solar system, and they are in their present version rather easy to install and use...
The fact is that the weak signal detecting and processing software is a major breakthrough in
amateur radio, making possible two way contacts that no one could imagine before the appearance of
this technology. As I have explained here several times, the LOWFERS or Low frequency bands
enthusiasts have played a decisive role in promoting the use of the low frequency bands, the 160 to
190 kiloHertz band in North America and the 136 kiloHertz band now becoming available to amateur
radio operators in many countries. If you want to learn more about kilometric wavelength
communications, this holiday season may be the right time to explore the INTERNET for more
information about Low Frequency Communications, one of the more than seventy six ways you and I may
enjoy this wonderful and fascinating hobby amigos !.

Now item three in detail: If you want to enter into amateur radio there are many different ways of
doing so, from opening up the check book or credit card and buying a sophisticated and also
expensive transceiver, antennas, towers etc. etc. to just homebrewing a simple radio that will also
put you on the air with an antenna that may be built at very low cost... If you ask me about which
one I will prefer, there is no doubt that I will go for the homebrew radio, as every second using it
will bring much more enjoyment than we you are just another electrical appliance operator using a
two or three or even six thousand dollars transceiver connected to an also very expensive tower and
antenna combination. Now, I must admit that for newcomers to amateur radio homebrewing will prove to
be a challenge, but you can always get help from other amateurs, especially if you are already a
member of a local radio club. That's why I always recommend to all of you interested in owning your
ham radio station, to go ahead and obtain the easiest license of them all, buy yourself a 2 meter
band FM handie-talkie and start using it to contact your local ham radio community... HF, or short
wave bands operations will come later, and you can use simple homebrew radios to enjoy talking to
people not across town, but across the continents !.

Here is a nice example of what I am talking about amigos !. There are now several transceiver kits
that are very reasonably priced, will save you the time and efforts trying to locate the components
and will help you to assemble the equipment with very well written step by step instructions... Or
you can go all out for homebrewing and build a replica of a World War II transceiver that was used
by paratroopers and behind the enemy lines radio operators.. It is known as the PARASET, and
apparently it is of British origin... With a very slight modification to the original 1940's
circuit, the PARASET provides the amateur with an amazing little radio that makes possible two way
contacts on a regular , daily basis when you use it on the 40 meter amateur band. If you want to
learn more about the PARASET, just drop me an e-mail and I'll be more than happy to send you all the
information about this unique set that can be assembled rather easily and will put you on the air
with a most relieable piece of equipment. All I can say that I have built so far not one , but three
of them, and they all have performed flawlessly from the very moment power was applied to them. The
slight modification I have made to the PARASET was to improve the regenerative receiver's
bandspread, in order to make tuning easier than on the original model. The PARASET's frequency is
controlled by a quartz crystal resonator, and mine produce from 2 to 8 Watts of power output, more
than enough to work Europe from the Caribbean when propagation conditions are good enough... You can
send for the PARASET INFORMATION PACKAGE, via e-mail: send mail to arnie@rhc.cu, OK, I'll say it
again, arnie@rhc.cu, and if you are not yet in cyberspace, just drop me a postcard to Arnie Coro,
Radio Havana Cuba, Havana, Cuba ,and I will send you the printed version of the PARASET
diagrams,photos and text files... Even if you continue your amateur radio career and buy yourself a
nice and expensive solid state transceiver, I am sure , that you will keep the homebrew PARASET in
its nice wooden box ready to operate whenever you feel like facing the challenge of QRP or low power
operation !

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On the air and on the world wide web, this is Radio Havana Cuba's Dxers Unlimited radio hobby
program , I am Arnie Coro, radio amateur CO2KK your host here , and here is item four of today's
program, our numero uno, the most popular section of this show... YOU HAVE QUESTIONS, and your amigo
Arnie tries to answer them .. Here is today's question, this one came from no less than sixteen
listeners, who wrote to arnie@rhc.cu via e-mail. The question was written more or less in the same
terms and essentially deals with something that is known as BPL or Broadband over the POWER LINES, a
system that uses the electricity distribution networks to carry into your home broadband digital
communications services , including INTERNET connectivity... Well amigos, this is now a very
controversial issue, and according to what I have read , learned and discussed with several digital
technologies expert engineers, BPL or Broadband over the POWER LINES,may prove to be a real menace
to radio reception as we know it today... in the range from as low as the AM broadcast band to as
high as the TV low band channels reaching up to 88 megaHertz. So amigos, the answer to your concerns
about BPL is that it is potentially very damaging to our radio hobby , but not only to us , but also
to other users of the short wave spectrum that may see their communications systems seriously
affected by the radio frequency interference generated by the BPL systems. And last but not least,
many engineers have the opinion that there is now way to stop the QRM or interference to users of
the radio spectrum coming from the BPL systems once they are in permanent service !. In fact the
problem is so acute that many telecommunications authorities around the world are now revising their
criteria about BPL and some of them may even decide to completely ban the installation of such
systems at all.

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And now amigos, at the end of the program, as always when I am in town, here is Dxers Unlimited's HF
plus low band VHF propagation update and forecast...

Solar flux presently hovering around 130 to 140 units, one BIG, and I mean BIG sunspot region in
sight, and this one is capable of producing M class solar flares during the next several days. The
effective sunspot number, the really important data item you want to provide to your propagation
forecasting software is now near 90 units, and that means that the daytime maximum useable frequency
curve will be reaching as high as 30 megaHertz and even higher on some selected paths... BUT, expect
rather fast downfall of the maximum useable frequency curve as soon as the Sun sets at your
location. Chances for 50 megaHertz or 6 meter band openings due to the winter Sporadic E season are
now increasing, so keep your watch on both 50.110 and 50.125 kiloHertz DX spot frequencies on the
magic band... Hope to see you all next Tuesday and Wednesday UTC days at the mid week edition of
Dxers Unlimited... Seasons Greetings amigos , and don't forget to take a little time and send me an
e-mail saying what you like and what you don't like about the program , in order to help me make it
a little better every time it goes on the air !!!