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Re: [HCDX] Dxers Unlimited's weekend edition for 17-18 November 2007
Radio Havana Cuba
Radio Havana Cuba's Dxers Unlimited weekend edition for 17-18 Nov 2007
By Arnie Coro
radio amateur CO2KK
Hi amigos radioaficionados, welcome to the weekend edition of Dxers
Unlimited, coming to you from Havana, I am Arnaldo, Arnie, Coro, radio
amateur CO2KK, your host here at this twice weekly radio hobby program,
coming to you when several of the major yearly amateur radio contests
will be taking place.
According to a last minute survey, right now there are no less than 224
countries or DX entities, as they are also known nowadays, are on the
air on on the amateur bands, , with many of them active during the
contests ... So, each ham radio contest becomes a nice opportunity for
adding new ones to your logs...
Item two: You can monitor the single side band voice contests on all
amateur bands from 160 to 10 meters, except on the WARC bands, that are
30 meters, 17 meters and 12 meters, because as a direct consequence of a
good will agreement those three bands are never used for ham radio
contests... By the way signals on the 160 and 80 meter bands should be
quite strong during your local evening hours, because ionospheric
absorption during the past several days has remained at very low levels
due to the prevailing very low solar activity...
Item three: If you pick up far away stations on the AM broadcast band
from 1.4 to 1.7 megaHertz, then chances that you can also tune ham radio
DX on 160 meters are quite good. Start tuning slowly from 1.8 megaHertz
up, with your receiver's BFO on, and remember that 160 meters does
travel quite far when solar activity is at very low levels...
Item four: At the request of many Dxers Unlimited's listeners the low
cost, easy to homebrew antenna for the two meters FM segment will be
presented today in our antenna topics section of Dxers Unlimited. It is
a version of the SUPER J antenna built using copper wire and PVC pipe...
a few cable tie wraps, some PVC electricians tape plus an optional
female antenna connector if you don't want to solder the coaxial cable
directly to the antenna is all you will need to build Arnie Coro's ultra
low cost Super J omnidirectional vertical antenna for the two meters
amateur band...
Stay tuned for the step by step instructions coming up in a few seconds
when Dxers Unlimited's weekend edition continues in a few seconds amigos:
.......
You are listening to Radio Havana Cuba , the name of the show is Dxers
Unlimited and yes, if you have already at hand paper and a pen of
pencil, then you can write down the step by step building instructions
to make your own omnidirectional Super J antenna for the two meters band.
The materials you will need are pretty easy to find at any hardware
store... Start with a 3 meters or 10 feet long PVC water pipe... You
will want to use the white PVC water pressure pipe, that has a rather
thick wall . The diameter of the PVC pipe may be between 25 and 50
millimeters, that is from one to two inches.
You will also need copper wire... with solid copper bare wire of number
10 or number 8 gauge prefered. If you can't find bare copper single
conductor wire locally, don't worry, as you can buy PVC insulated wire,
the type used for domestic electrical installations and then proceed to
very carefully remove the PVC plastic insulation with a sharp knife. I
must emphasize that this must be done with great care, so if you can go
to an electrician's supply store and buy bare copper wire, that's going
to be the best option. You will want to buy no less than 10 meters or
about 33 feet of number 10 or number 8 wire, that will be enough to make
at least two antennas...
Now you will ask me why buy so much wire, if you are going to build just
one antenna, and the answer is that once the first one is installed,
making a second one is very easy, and the second antenna can be kept
ready to be transported so that it can be installed immediately during
an emergency...
A supply of no less than 20 or 25 cable ties of the heavy duty type is
also required, as well as a roll of PVC electricians tape of about 12
millimeters or one half inch width.
In case you want to have the possibility of connecting and disconnecting
the antenna to a coaxial cable line, instead of soldering the coaxial
cable directly , then you must also buy a female coaxial connector. Of
the three popular coaxial connector types, the best one for this antenna
is the female SO239 standard coaxial connector.... because it is a very
rugged connector and the male plugs for it are easy to find , as almost
every radio amateur seems to have at least a few of them in the toolbox.
Assembling the SUPER J copper wire antenna is a very easy job, as you
will only need to shape the wire so that it will start with a vertical
half wave element, continue with a quarter wave phasing section, then go
down forming another half wave vertical element, and ending up by
forming with the wire a quarter wave matching section at the bottom of
the antenna.
Once the wire is shaped in the form of the Super J antenna, proceed to
tie it with the plastic tie wraps to the outside of the PVC white pipe,
leaving about 30 centimeters of the pipe free at the lower end , in
order to be able to support the antenna to a mast or tower.
A length of wood dowel that will fit tightly into the PVC pipe lower end
for about 30 centimeters is also required, so that the pipe will have
enough strength to support the bending when the wind blows.
After some practice, members of one of our local City of Havana radio
clubs have built some fifteen of these antennas... as part of a club
effort to have as many 2 meter band stations as possible equipped with
outdoor antennas, instead of using the typical handie talkie rubber duck
helical antennas that provides much shorter communications range. With
the new SUPER J antennas the stations are able to achieve much longer
ground wave range, and at least two of them have reported excellent
reception of amateur satellites when they are flying near the horizon.
The exact lengths of the antenna elements , phasing line and matching
section will depend on the frequency range where it is going to be
used... so, I have prepared a small computer file with the building
instructions and a table showing the lengths required to operate on the
band segments where FM repeaters are in use all around the world. You
can send your request for the SUPER J Antenna File to arnie@xxxxxx,
again, arnie@xxxxxx, and I am sure that if you are already an amateur
radio operator or are thinking about obtaining your ham radio license
soon, this easy to build , low cost antenna will be an excellent weekend
project that you will be proud about.
Again send for the SUPER J Antenna file to arnie@xxxxxx, and don't forge
to add a few lines to your request with a signal report of our station,
and comments about Dxers Unlimited content and what you want to hear in
future programs amigos !!!
.......
More about amateur radio contests that are so popular at this time of
the year.
If you happen to own a receiver that has a BFO, that is a beat frequency
oscillator and for that reason is capable of picking up single side band
and CW signals, then here are some tuning tips, so that you can pick up
ham radio stations participating in the contest... During your local
evening hours the amateur bands most likely to be full of contest
stations are 40 and 80 meters...
The 40 meters phone band starts around 7025 kiloHertz for stations
located in ITU regions I and III, plus also Latin American stations that
are located in ITU Region II... so start scanning slowly with your
receiver's BFO on starting on 7025 kiloHertz and there are very good
possibilities that stations that are participating in the contest will
be heard... Constest operators on 40 meters many times use the so called
split mode, that meaning that they will transmit on one frequency and
listen on another, something they will announce very clearly when
calling... It will sound something like this... CQ contest CQ contest CQ
contest CO2KK, CO2KK calling CQ contest listening seven one seven
five... And that means that CO2KK, my amateur station operating on say
7050 kiloHertz , instead of listening for answers on my own 7050
kiloHertz frequency will be trying to pick up stations operating on 7175
kiloHertz... I can also add to that call the words MY FREQUENCY , that
meaning that I will trying to pick up answers to my CQ contest call, not
only on 7175 but also on my own operating frequency 7050 kiloHertz...
Very late in the evening your local time, and using even a portable
radio's telescopic whip, you may be able to pick up the most powerful
contest stations on the 80 meters band, by tuning slowly from about 3775
kiloHertz up the band... And if propagation conditions are really good,
160 meters band contest stations using big antennas and high power can
be heard between 1810 kiloHertz and around 1900 kiloHertz...
A lot of practice is required to operate during an amateur radio
contest... because so many stations are on the air at the same time, and
the pretty rare ones are called by everyone !!!
Winning one of the major amateur radio contests is really very
difficult, a lot of skills are needed, and good luck with propagation
too... but even if you just spend a few hours operating during a major
ham radio contest, a lot of new countries can be added to your logbook !!!
.......
Si amigos, yes my friends, Dxers Unlimited is on the air also on
Tuesdays and Wednesdays UTC days, and the weekend edition is broadcast
on Saturdays and Sundays UTC days... You can send your QSL requests via
e-mail to arnie@xxxxxx, and VIA AIR MAIL send a postcard or letter with
your signal reports, comments about the show and any radio hobby related
question you may want to ask to Arnie Coro, Radio Havana Cuba, Havana, Cuba.
And now before going QRT , here is our exclusive and not copyrighted HF
plus low band VHF propagation update and forecast ...
Solar activity continues to be at rock bottom levels... a very small
sunspot appeared briefly this week and vanished... and once again the
daily solar observations showed an almost blank , but today the Sun has
a single sunspot… just one and not powerful, but YES, it is a sunspot.
Also the heliosysmic observations that allow scientists to know about
solar activity happening on the side of the Sun that we don't see from
Earth, show that there is no active sunspot region there. Solar flux
hovering around base levels, and according to the most recent reports,
we won't see the first signs of solar cycle 24 until the second half of
2008... Hope to have you listening to our mid week edition of Dxers
Unlimited next Tuesday and Wednesday, and don't forget to send your
signal reports, comments about the program , QSL requests and radio
hobby related questions to arnie@xxxxxx, or VIA AIR MAIL to Arnie Coro ,
Radio Havana Cuba, Havana, Cuba.
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