Radio Habana Cuba
Dxers Unlimited
Dxers Unlimited's weekend edition for 29-30 October 2005
By Arnie Coro
radio amateur CO2KK
Si amigos ! This is the weekend edition of Dxers Unlimited, coming to you as
a yearly amateur radio single side band contest is in progress, while the
Sun is as quiet as you can imagine, with five days in a row of an absolutely
spotless solar disk... Nevertheless, listening to the ham HF bands Saturday
morning here in Havana, showed once again that an amateur radio contest that
brings up a lot of activity has amazing and surprising properties, even when
the solar flux is hovering very near the baseline figure of 70 units, and as
I said a moment ago, the sunspots are simply absent...
Item two: The thirteenth hurricane of the season, named BETA, because
already all the letters of the Latin alphabet were used , is now aiming at
Central America, and late Friday and early Saturday was hitting hard San
Andres and Providencia islands in the western Caribbean. Once again amateur
radio emergency nets are linking the affected areas to the rest of the world
when professional communications systems fail due to the hurricane force
winds and heavy rainfall.
Item three: A listener wrote from Mallorca, in the Balearic Islands of Spain
asking for more information about the NVIS , Near Vertical Incidence
Skywave antenna systems. He describes his location as far from ideal for
short distance HF communications, and wants to install one of these antennas
that will help him to be able to talk via skywave to the other nearby
islands of Menorca and Ibiza, that form part of the Balearic Islands
archipelago...
Item four: Taking care of rechargeable batteries is a very important aspect
of emergency preparedness... overcharging lead acid accumulators will ruin
them, and will also generate dangerous fumes... So, later in this program, I
will tell you more about safe ways to assure that your rechargeable
batteries will be ready when the emergency comes !
Now stay tuned right on this frequency , or if you are listening to our
Internet streaming audio in English that is on the air from 05 to 07 UTC,
keep the connection , as Dxers Unlimited's weekend edition will continue in
just a few seconds... I am Arnie Coro, radio amateur CO2KK in Havana...
.....
This is Radio Havana Cuba, the name of the show is Dxers Unlimited, and for
those of you that are picking up this program for the first time, let me say
that it's on the air twice weekly with the most up to date radio hobby
related information, including my special HF plus low band VHF propagation
update and forecast, that today will provide ham radio contest operators
with a special report ... Several years ago I wrote an article about my
first six meter band contact, that happened way back in 1959, the article
was published by the UK 6 meters Group website and their excellent
specialized 50 megaHertz band magazine... At the request of several
listeners of Dxers Unlimited, I am pleased to present here today that
article, that I hope you will enjoy as many of the UK Six Meter Group
members did way back in 1998...So here I amnow starting to read the article:
My First Six Metre QSO
Arnie Coro, CO2KK (at that time CM2DL)
Issue 57, May 1998
It was way back in 1959... November 16th 1959 to be exact. My good friend
Pepe, CO2GX, now a silent key, was keeping his 4-400 with 3000 volts on the
plate on 50.400 for me to find his carrier on my 6C4-12AX7-6AQ5 regenerative
receiver... For those not familiar with those 'valves' or 'tubes' they are
the equivalents, more or less, of an EC92, an ECC83, and the audio output I
think is an EL??? Well, that's not really important, what matters is that
2GX kept talking and talking, while I frantically tuned the
super-regenerative detector looking for him... Finally, after about half an
hour, I hear Pepe's voice loud and clear...
My just finished two element beam fed with RG58U was picking up my friend's
signal so loud, that I had to turn down the volume control... (Yes I had to
tune a bandset capacitor with a screwdriver to find him, that was the reason
for the delay).
Pepe was on 40 metres also, as we were using that band for liaison, he asked
me many times if I had found his 50.400 AM, and sure enough, I finally came
back to him with a " te copio Pepe.", "I read you Pepe ..." and feedback...
as his audio, picked up by my receiver, was going back to his QTH via my own
40 metre rig...
Then Pepe said... go ahead and transmit... I am now tuning the band for you.
I fired up my little three watt rig on 50.100 ??? and CO2GX answers my call,
not on six, but on 40 metres... and once again there was the feedback... as
we soon "discovered" that we had an excellent full duplex link... 7 MHz to
50 MHz !
I marked the super-regen dial very carefully at the 50.400 CO2GX frequency,
and asked Pepe to change his crystal, something he did by just removing the
quartz from the holder... only to find outthat his 'crystal control' was
partial, as I could still hear him without a crystal in his rig!
Arnie C02KK plugged in a 50.100 rock, and I found him very easily, as my
main variable capacitor had but one single movable plate, so my bandspread
was quite nice... (finding the right setting for the bandset was, of course,
the real problem!). Two minutes later, I told Pepe to turn down the volume
on his 40 metre receiver, proceeded to call him on Six and he came back to
me on 50.400! Those were the days of crystal control, when stations had to
look for others exploring from about 50.000 to 51.500 Megahertz, as that was
the range of the crystal frequencies available here in Cuba. It was not
surprising to hear a QSO going on between a station on 50.400 and another
guy on 51.500.
Yes, that was my first six metre QSO, followed a few hours later by an F2
QSO with a California ham whose call I can't remember... all I recall that
he was in Pomona, and that I could copy him very well for a few minutes
around eleven o'clock in the morning my local time...
This was ... let's see ,almost 39 years ago... and Six continues to
fascinate me, like that very first day I remember so well .
Well, that was the article that was published in 1998 by the UK Six Meter
Group magazine and website...that I hope you have enjoyed... and of course,
even during solar minimum years, Six Meters continues to be THE MAGIC BAND,
with many different propagation modes available, like Sporadic E, Auroral E
FAI an acronymn for a mode of propagation that is known as Field Aligned
Irregularities, and from time to time, stationary cold fronts provide
tropospheric ducting that sometimes open up six meters for long distance
groundwave propagation too...
You can learn more about SIX METERS, the magic band, by visiting http://www
uksmg.org, again the URL to go to is http://www.uksmg.org
.......
Si amigos, your radio hobby related questions are answered fast when you
send them to arnie@rhc.cu, I send the answer direct to your e-mail, and many
of them also go on the air to help others that may have similar questions
and can benefit from the answers... today's question came from Mallorca,
Spain... ham radio operator andshort wave listener Guillermo, EA6XD, wanted
to know why I prefered to use a folded dipole driven element for my special
NVIS Yagi antenna instead of a regularsingle wire half wave dipole... The
answer to Guillermo's question is that because reflector element is located
very close to the driven element, if you use a standardhalf wave dipole ,
the impedance at the center will go down to between 12 and 15 ohms... ...
then if you use a folded dipole, the impedance will move down from 300 ohms
to about 50 to 60 ohms, so you will only need a one to one balun to connect
your feedline... By moving the folded dipole driven element up and down, you
can find the height above the reflector that gives the minimum standing wave
ratio. In many of the antennas that I have built, the SWR can be brought
down to less than 1.2 to 1, an almost perfect match for all practical
purposes, and if you are a perfectionist, then , simply connect the antenna
to your transceiver or transmitter by means of an antenna tuner !!!
And now amigos, just before going QRT, here is our exclusive and not copyrighted , in the public domain, for free distribution to all radio hobby enthusiasts, Arnie Coro's Dxers Unlimited's HF plus low band VHF propagation update and forecast. Solar activity is at extremely low levels... no less than five days in a row without a singlesunspot ... zero sunspot count, and the microwave solar flux at 2800 megaHertz is hovering near the minimum baseline activity figure... Very quiet geomagnetic conditions will prevail, and the maximum useable frequencies will be rather low, with short , but useable time windows when you can certainly work DX with your average power 100 Watts amateur transceivers... For contest operators, excellent conditions on the 160, 80 and 40 meter bands will let you add lots of multipliers, but during your local daylight hours on Sunday, do go to 10 and 15 meters as I expect some nice openings on those two bands until late afternoon local time. And don't forget to set a little time aside when the contest is over to tell me about how many DX entitities you worked or monitored , and it this propagation forecast helped you !!! Send mail to arnie@rhc.cu, or VIA AIR MAIL, send a postcard or letter to Arnie Coro, Radio Havana Cuba, Havana , Cuba