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RE: Dxers Unlimited's script for mid week edition 2-3 October 2007

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  • Prof.Arnaldo Coro Antich
    Radio Havana Cuba Dxers Unlimited Dxers Unlimited’s mid week edition October 2 -3 -2007 By Arnie Coro Radio amateur CO2KK Hi amigos, welcome to our mid week
    Message 1 of 1 , Oct 2, 2007
      Radio Havana Cuba
      Dxers Unlimited
      Dxers Unlimited’s mid week edition October 2 -3 -2007
      By Arnie Coro
      Radio amateur CO2KK

      Hi amigos, welcome to our mid week edition , coming to you Tuesdays and
      Wednesdays UTC days. I am Arnie Coro , radio amateur CO2KK your host
      here in Havana, and as always it is my pleasure to share with you about
      seventeen minutes of on the air and on the web time. Here is now item
      one of today’s program: The Headline : Back to Zero , yes back to zero
      sunspot count after a very short break , when a single small sunspot was
      seen… according to a recent analysis by a group of well known solar
      scientists, cycle 23 actual minimum has required no less than three
      revisions, and it has certainly extended beyond all forecasts. Another
      relevant piece of information about this solar cycle is that the number
      of consecutive days without sunspots has so far extended into two series
      of great significance, when compared with other previous solar cycles.
      For short wave listeners and amateur radio operators, as well as for
      professional users of the HF spectrum, cycle’s 23 extended minimum has
      already had a very significant negative impact, including, in the case
      of amateur radio, rather low scores during the latest contests !!!
      Item two: Less time on the air, or more time using the highly efficient
      digital modes, like the PSK31 keyboard to keyboard brainchild of G3PLX
      Peter Martinez that with just 10 Watts transmitter output and even a
      very simple antenna is capable of providing nice two way amateur radio
      contacts. Yes less time on the air is one option for ham radio operators
      at this present stage of the solar cycle, that can then be devoted to
      more home construction of radios, one of the 81 wonderful ways of
      enjoying our wonderful hobby. At a recent edition of Dxers Unlimited, I
      talked about new approaches to the design and construction of simple
      short wave receivers, that have already proven to be quite feasible for
      the average home builder… The Wheatstone Bridge Regenerative Receiver
      Circuit is now available in both a vacuum tubes and a solid state
      devices versions .. The solid state version provides amazing performance
      according to my breadboard prototype tests, and it is also quite amazing
      that this receiver works from a single 1.5 volts battery and requires a
      current of less than one milliampere to provide full output into the
      headphones. The circuit is very simple, and easy to reproduce without
      requiring the use of a printed circuit board… as a matter of fact you
      can assemble it using the now classic small islands technique, that is
      gaining favor among homebrewers of ham radio gear…
      Si amigos, yes my friends, oui mes amis… HF propagation conditions may
      be very poor, band openings above 20 megaHertz rare or non existent, but
      the radio hobby has so many different aspects that can be enjoyed ,
      among them homebrewing receivers that have a very special sound when you
      use them… because I can assure you that a radio that you assemble has a
      unique sound to your ears… build your first homebrew radio and when it
      starts bringing in stations, even if the first one is the local AM
      broadcast band super power 50 kiloWatts transmitter , you will agree
      with me that your homebrew radio has that very special sound too…
      Stay right here on this same frequency or world wide web connection …
      Dxers Unlimited’s mid week edition will continue in just a few seconds
      amigos …
      ……

      This is Radio Havana Cuba, the name of the show is Dxers Unlimited and
      here is item three of the show… ASK ARNIE, la numero uno, the number one
      most popular section of the program… The question that I will be
      answering today here came from Australia, more precisely from Perth,
      where amigo Ian picks up RHC’s 9550 kiloHertz frequency during the two
      yearly equinoctial periods with what he describes as “amazing
      reception”… Amigo Ian wants to know more about the best antennas for
      picking up very distant stations, that may be reaching his receiver at
      very low angles above the horizon. Well Ian, low take off or receiving
      angle antennas are difficult to install at urban locations, and the only
      type of antenna that provides really low take off and receiving angles
      above the horizon suited for an urban area is unfortunately prone to
      picking up a lot of man made noise, something that will make reception a
      lot more difficult.
      During solar cycle 21 , I had installed a vertical antenna for the 20
      meters amateur band that was about 120 electrical degrees high, and had
      six elevated radials . The antenna itself was installed on my rooftop,
      but the bottom of it was elevated about three meters from the reinforced
      concrete roof. The six radials worked as the elevated ground plane, and
      this antenna provided wonderful DX contacts around the world while using
      less than 100 Watts. The zero decimal thirty three wavelength vertical
      with elevated ground plane sent out and received signals at very low
      angles above the horizon , and it worked so well that several of the
      local ham radio Dxers visited me just to see the antenna, as during pile
      ups, I often made contact with the rare DX station before the owner of
      the best 20 meters 4 element Yagi antenna in town.
      He was scratching his head how could CO2KK could beat him breaking a
      pile up, when he had installed a huge 4 element full size 20 meters
      Yagi… and I had to spend quite some time to explain to him that he would
      need at least a 120 feet or about 36 meters high tower, in order to
      achieve the low take off angle that my elevated ground plane was
      providing. Fortunately at my city location, the noise level is rather
      low, because as I have explained here several times, the man made noise
      , man made interference is mostly vertically polarized, so a vertical
      antenna picks up a lot more local noise than a horizontally polarized
      antenna…
      Amigo Ian, I have already sent to you the sketch of the elevated ground
      plane antenna for 20 meters, which is the most popular DX band among
      radio amateurs. You will also see in the drawings a table of dimensions
      for the 17, 15, 12 and 10 meters band. An elevated ground plane antenna
      for the lower frequency amateur bands like 30, 40 and 80 meters will be
      difficult to build and install, and that’s why I didn’t include
      information about them.
      Now another question , this one came from Canada , where the short wave
      listening hobby is , according to my analysis, a mostly winter time
      activity for many Canadians… although as my good friend Bob Chandler ,
      radio amateur VE3SRE from Toronto has told me, the summer time ham radio
      contests, like the one held during Canada Day national celebration are
      also very popular… The question came from
      Quebec City, where amigo Robert lives. He wants to know about amateur
      radio satellites, and how easy or how difficult it is to operate using
      them. Well amigo Robert, ham radio satellite activities , in my opinion,
      have gone down significantly after the failure of several of the most
      popular birds, as the satellite enthusiasts call them. As a matter of
      fact, the failure of RS10 and RS12 , followed by Oscar 40 has left out
      of the picture both the simple station operators and those who spent a
      lot of time and resources to install a complex Earth station to work the
      Oscar 40 satellite. At this moment the amateur satellites that are
      available provide very short time windows to communicate, due to the
      fact that they are all in the so called Sun synchronous orbits, at
      rather low altitudes, and they don’t have , as far as I know, HF bands
      inputs or outputs… So amigo Robert, we must wait and see if a new ham
      satellite project in the works can finnally be completed , and a Molnya
      elliptical orbit satellite can be launched … As regards to your question
      about why there are not stationary ham radio satellites, like the ones
      used for telecommunications and relaying TV signals, the answer is a
      very simple one amigo: they cost a lot of money, and so far it has
      proven impossible for any of the amateur satellite organizations to
      collect enough resources to even think of starting such a project.
      Another possible approach would had been to find a geostationary orbit
      satellite to which an amateur radio transponder could be attached, but ,
      again, so far, this has proven to be impossible…
      You can still have fun with a dual band 70 centimeters and two meters FM
      transceiver and a simple hand held antenna by communicating with the low
      earth orbit ham satellites that are now in operation , but your fun will
      have a very limited time , because even on the best passes, the time
      available to communicate is limited to fifteen minutes or less.
      And now amigos, just before going QRT, here is Arnie Coro’s Dxers
      Unlimited HF plus low band VHF propagation update and forecast… Solar
      flux continues at very low levels, with the actual flux measurements not
      going over 67 or 68 units… and do remember that the lowest registered
      microwave solar flux was 64 units… Sunspots are non existent… sunspot
      count again zero after a brief spell when a very small sunspot emerged
      and then vannished… Expect daytime maximum useable frequencies not to
      exceed 20 megaHertz for 90 percent of the time, and barely moving above
      21 megaHertz for very short periods on the best possible propagation
      paths, that again will be North to South, and vice versa, with the East
      to West path showing the worst propagation , as expected during extended
      periods of very low solar activity. Trans equatorial DX season still in
      progress, with options opening for 6 meters band ham radio operators for
      nice contacts from the South of the US, Mexico and the Caribbean, to
      Brazil, Argentina, Uruguay, Paraguay and Bolivia, and slightly less
      chances of contacts on six meters via TE scatter to Chile and Peru. Join
      me next Saturday and Sunday UTC for the weekend edition of Dxers
      Unlimited, and don’t forget to send your signal reports, QSL requests
      and comments about the program to arnie@... or VIA AIR MAIL to Arnie
      Coro, Radio Havana Cuba, Havana, Cuba
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