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Re: [HCDX] Dxers Unlimited's week end edition for 28-29 July 2007
DXERS UNLIMITED
DXERS UNLIMITED'S WEEKEND EDITION FOR 28-29 JULY 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 provides information
about the more than eighty one ways you and I enjoy playing with our
radios !!! For you amigos that are listening for the first time my best
wishes, and I hope to you have join me twice every week to learn more
about the wonderful radio hobby in a year during which solar activity
is expected to continue declining as we transit towards the end of solar
cycle 23, one of the most interesting ones on record... Si amigos, it's
your friend Arnie Coro in Havana, ready to share with you all about
seventeen minutes of on the air and on the web time, and thanks to the
Ontario DX Association you can also read our scripts by subscribing to
the ODXA Yahoo mailing list... Now here is item one : E-mail messages
reaching my computer everyday speak highly of Dxers Unlimited's
listeners around the world, as many of you mention an interest in
learning more about amateur radio and how you can join radio clubs .
Amateur radio is one of the finest areas of the radio hobby , and more
than two million people worldwide that have licenses to operate amateur
radio stations can't be wrong !!!. As a matter of fact, despite some
dreadful forecasts about the negative impact of the Internet and
computers on the radio hobby in general and amateur radio in particular,
the opposite seems to be the truth, as both the Internet and computers
have proven to be a remarkeable assett helping to develop the radio
hobby into new and never before seen activities... For those of you not
familiar with the extraordinary amount of online information about
amateur radio that is provided absolutely free of charge, my advice is
to run a search on Internet by typing amateur radio and just sitting
down to watch the results... Try it, and you will agree with me that the
prophets of the doomsday of amateur radio due to the Internet were
fortunately mistaken !!! And YES we can still do a lot more to promote
this wonderful aspect of the radio hobby that helps people around the
world to communicate with each other , even from places where wired
connectivity is ZERO !!!
Item two: How many radios , yes how many radio receivers do you happen
to own ?? Everyone in developed nations has at least two radios
available for listening, and some people have even more !!! If you are a
short wave listening enthusiast and already own a nice short wave radio,
follow your friend's Arnie Coro's advice and try to get a second
receiver... As you become a more advanced short wave listener, you will
find yourself leaving one receiver on a certain frequency taping a yet
unidentified station for later analysis, while the other radio is used
for listening to a program you enjoy ,like for example ... YES, Dxers
Unlimited !! Monitoring the short wave radio spectrum with two receivers
at the same time is a very rewarding experience, as you can learn a lot
about how international shortwave broadcast stations use satellite links
to deliver the audio to remote transmitting sites !!! Item three of
today's Dxers Unlimited will be our technical topics section, item four,
the popular you have questions and Arnie tries to answer them and as
always when I am here in Havana, at the end of the program, have your
tape recorder or notepad ready to copy our exclusive and not copyrighted
HF plus low band VHF propagation update and forecast amigos... Stay
tuned , Dxers Unlimited coming to you from Radio Havana Cuba will
continue in a few seconds...
......
The radio hobby amigos is really fascinating,and in order to enjoy at
its maximum , you must make an effort to learn about the technical
aspects involved. In the beginning this may seem difficult,but little by
little, and as time goes by, you will find yourself learning a lot about
topics like electronics, antennas and radio wave propagation... That's
the main purpose of Dxers Unlimited's TECHNICAL TOPICS SECTION... and
here is an example..The two meters amateur VHF band is considered by
many as the most popular one around the world, and those who think so
may be quite right, as rather inexpensive and easy to operate FM
handheld transceivers, popularly known as handie-talkies , have helped
to populate two meters with the aid or repeaters located at high rise
locations like mountain top TV and FM station's sites and downtown high
rise buildings. Many radio amateurs start their ham careers by obtaining
the basic license and buying a 2 meter band FM hand held... that
provides them with the first contact with the hobby. That's why I am
always trying to learn more and experiment about simple low cost
homebrew antennas that can extend the range of the typical one to five
Watts output Fm handie-talkie for the two meter band. One of my most
recent experiments originated when I read an article published by
ANTENNEX,an on line WEB E-zine that is totally devoted to antenna
related topics. The antenna that I tried to homebrew from the ANTENNEX
article data is a version of the so called DDRR or Directional
Discontinuity Ring Radiator, one of the most interesting antennas that I
have ever seen in my long time of enjoying amateur radio. The version of
the DDRR for 2 meters is extremely compact and can be made in a couple
of hours using simple tools...You won't need to be a mechanical or
electronic genius to homebrew this antenna. All what is needed is a
square of high quality copper clad printed circuit board of 10 by 10
inches, or roughly 25 by 25 centimeters, that acts as an almost perfect
ground plane for the DDRR antenna. The DDRR radiating element is very
easy to make and adjust to a perfect one to one standing wave ratio
match... As a matter of fact, after testing the roughly built first
prototype, I immediately started to think about building two more of
them, one for my son's station CM2KW, and another one for my portable
emergency communications package, because this is a very low profile
antenna that will stay up even under very heavy winds. The DDRR is easy
to homebrew , and its low height above the ground plane makes it, as I
just said, ideal for use during severe weather conditions. I have both
text and graphic information about the 2 meter band Directional
Discontinuity Ring Radiator, or DDRR antenna ready to be sent to you
amigos... just send an e-mail to arnie@xxxxxx, again, slowly
arnie@xxxxxx, and request the 2 meter band DDRR antenna project files...
If not yet in cyberspace, just send a postcard to Arnie Coro, Radio
Havana Cuba, Havana, Cuba, and I'll send you a printed copy of the DDRR
antenna for the two meter band...
.....
Now here is our very popular you have questions and Arnie answers them
section of the program. Today's question sent by listener Karl in Vienna
, Austria.... He wants to know if he can use an underground antenna for
his HF bands amateur radio rig, as that seems to be the only possible
solution for him... Well amigo, let me tell you that carefully installed
and well engineered underground antennas do work very well indeed !!! As
a matter of fact, you may find that feeding an underground antenna with
about 100 watts of radio frequency power, your signal will be heard
within a certain area sorrounding the station with very good intensity,
due to the so called near vertical incidence skywave propagation. ...
The undeground antenna's behavior will show a rather high loss, compared
to a standard full size half wave dipole antenna installed at no less
than a quarter wavelengh above ground.. the underground antenna will
show a loss anywere between 6 and 24 decibels below a standard half wave
dipole installed at one quarter wavelength above ground ... So you will
need to run more power into it than what normally you will operate
with... anyway, there is another added bonus: underground antennas pick
up much less man made noise, so reception with them in the frequency
range from 160 meters to 40 meters is sometimes better than with an
above ground antenna system... Surprising as this may sound to those of
you not familiar with antenna technology, underground antenna systems
are in regular use by professional telecommunications systems with very
special requirements, and they are well known to antenna designers !!!
So amigo Karl, start digging your garden , buy yourself large diameter
PVC pipe and install your underground antenna as soon as possible to
start enjoying the 80, 40 and 30 meter bands you told me in your e-mail
that you want to start working ... BUT, don't expect a lot of DX from
your underground antenna system... !!!!
I
Si amigos, you are listening to Dxers Unlimited, this is our mid week
edition that is on the air Tuesday and Wednesdays UTC days... you can
send for our nice QSL cards by mailing a signal report and comments
about this and other Radio Havana Cuba's program to arnie@xxxxxx, or VIA
AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana , Cuba...
And now amigos, just before going QRT, here is our number two most
popular section of Dxers Unlimited, Arnie Coro's HF plus low band VHF
propagation analysis, updates and forecasts.. Very poor HF propagation
conditions expected during the next three to five days... extremely low
solar activity is keeping the ionosphere's ionization at extremely low
levels... So , my advice is to monitor the bands above 10 megahertz
after your local sunset amigos... Solar flux near rock bottom minimum of
67-70 units, with six days in a row of absolutely NO Sunspots ...
Sunspot count ZERO for a whole week ... Send your signal reports and
comments to arnie@xxxxxx or VIA AIR MAIL to Arnie Coro, Radio Havana
Cuba, Havana, Cuba
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