Radio Habana Cuba

Dxers Unlimited

Dxers Unlimited's mid week for 24-25 November 2007 By Arnie Coro radio amateur CO2KK

Hi amigos radioaficionados.... this is the weekend edition of Dxers Unlimited. I am Arnie Coro, radio amateur CO2KK, and as always its my great pleasure to share with you about eighteen minutes devoted to the promotion and development of this wonderful hobby, described by sociologists that do research about the use of spare time as one of the most socially useful hobbies of them all....

The radio hobby is especially rewarding for people that are disabled in any way , and is listed among a favorite among persons with visual problems. One of my long time friends Jose Oliva, radio amateur CO2JO, was born blind, and he describes ham radio as an essential part of his life. Radio clubs should help disabled persons interested in becoming radio amateur operators, and the club's executives will soon find out that those new members usually become very active in club activities, helping to keep the club alive.

Item two: Effective sunspot number continues to be zero or barely above zero form many, many days in a row..., and the A index moved down now after climbing up to 17 units this week due to the effects of a high speed solar wind impacting upon the Earth's magnetosphere... According to solar researchers there are no sunspots in sight at the back side of the Sun. and that means that solar activity will stay in the low to very low range , making the winter DX season particularly poor, as HF propagation conditions in general go, with a slightly better nightime situation for the frequency range from 2 to 10 megaHertz....

Item three: take a piece of 300 ohms TV ribbon twinlead , some household wire, a small piece of PVC half inch diameter pipe and a length of nylon rope... Spend about an hour or an hour and a half of your spare time, and you will end up with a very nice looking SUPER JAY 2 meter band antenna... It's ideal to take when you are travelling, as it has about 2 dB more gain than the classic TV 300 ohm ribbon JAY antenna that is so popular among 2 meter band operators...

For those of you interested in obtaining the complete pictorial diagrams that show in great detail how to build this antenna for the two meters amateur band, I have the small dot gif computer file ready to be sent via e-mail, so,send your request to arnie@rhc.cu , again, arnie@rhc.cu... And for those listeners without e-mail capability, just send a postcard to Arnie Coro, Radio Havana Cuba, Havana, Cuba and please include your postal address and in a line " request for 2 meters amateur band wire SUPER JAY antenna...

Now standby for a few seconds, as Dxers Unlimited's weekendn edition will continue in just a few seconds, after this short musical interval..

I am Arnie Coro in Havana.

......

Si amigos ! The winter Dx season of the northern hemisphere is now in progress , bringing in some nice DX on the 75 meters or 4 megahertz and the 49 meters or 6 megaHertz, international short wave broadcast bands... Late evening catches on the 49 meters band are now plentiful, especially past midnight your local time... The SINPO reports with one of my two vacuum tubes regenerative receivers for many stations on that band are now a full set of five fives, and that with a simple 3 meters or 10 feet long wire antenna... Just to complete the report I heard several nice DX stations at 4 o'clock in the morning local time here in Havana, that is 0900 hours UTC..

Item five: Listeners reports for Dxers Unlimited usually come with a few more goodies than the report itself... for example, imagine how do I feel when a listener tells me that she or he learned about amateur radio by picking up my show, and then adding that after taking the radio amateur license test she or he is enjoying such interesting two way contacts as contacting with the International Space Station crew, or working one of those really hard to catch DX expeditions ...And of course that many of the e-mails , post cards , letters and fax messages come with radio hobby related questions that I try to answer as soon as possible directly in the case of those coming via e-mail... Talking about answering questions, here is today's ASK ARNIE, la numero uno, the most popular section of Dxers Unlimited first question coming from....

Listeners Rudy in Germany and Felipe in Havana: they want to know if it is really worthwhile to build a VHF log periodic antenna , as both of them have the same problem... they are apartment dwellers and their apartment buildings rules and regulations don't allow the installation of external rooftop antennas... Both Rudy and Felipe are fortunate to have balconies, so they can place a small single antenna on a short mast in the balcony and use a short section of coaxial transmission line to the rig. I already gave Felipe the detailed instructions on how to build a 7 elements log periodic that will let him start working stations in the frequency range from 110 to 220 megaHertz... Felipe is an amateur radio operator so he has up to now kept his on the air activities to the two meters band, where he runs a 25 watt tabletop FM transceiver and a zero db.gain JAY type vertical antenna attached to the balcony rail...

In a few days Felipe will be testing his new log periodic, that will give him about 5 dB gain over the previous antenna in use... He is still gathering all the materials needed for building the antenna , he told me during a phone call Friday. By the way, Rudy was faster than Felipe, and bought a very nice factory built log periodic antenna...according to his e-mail it is working very well, already providing many nice two way contacts on the 2 meters band using Rudy's favorite mode, FM voice,and also he hasmade several two way contacts using the digital keyboard to keyboard modes that are now becoming some popular amont the world's amateur radio operators....

....

As solar cycle continues to transit through a very extended period of minimum activity, researchers are learning more about the upcoming cycle, number 24 since mankind learned about the ciclycal nature of the Sun's sunspots...Well, so far the news coming are not very encouraging, as almost all recently published scientific papers that have approached the forecasting of cycle 24 coincide in that it is very probably going to be a less active cycle than the two previous ones..But as I quoted here recently, some other scientists still believe that cycle 24 is going to be a very active one.But, just in case, the forecasters that are saying that upcoming solar cycle 24 is going to be a very slow moving one are right, follow your friend Arnie Coro advice and start thinking about longer wire antennas, the ones that will bring in the elusive low frequency bands DX during the bottom of this solar cycle and the first one or two years of the upcoming cycle 24 expected to begin by the end of 2008..

Item seven: Lots of amateur radio software , absolutely freeware, with no bugs or embedded malicious software, now available if you run any of the standard distributions of LINUX.. Si amigos, ham radio software for LINUX is growing at a fast pace, and there are many interesting programs for high frequency propagation forecasting, operating using the digital modes and keeping contest scores... Old machines even 486's and Pentium ones run very nicely using some of the smaller and simpler LINUX operating system distributions. !!!

Item eight: Question, what 's the best band to monitor for Dx during

the local daylight hours.during solar minimum.. Answer, the highest frequency band that is open at the specific time you are going to listen or to call CQ DX if you are an amateur radio operator... The reason for this is very simple, the higher the frequency the less daytime ionospheric absorption, so signals on 10 meters, if that band is open , will be much stronger with the same power levels than signals on 20 meters... You may hear both 20 and 10 meters open at the same time, but , I can assure you that signals on 10 meters will generally be stronger due to the much less absorption of radio waves by the D layer of the ionosphere at higher frequencies...

Another question sent in by a US listener that has just moved to a farm:

Arnie, if one has the possibility of installing three antennas for operating an amateur station on the HF bands , please tell me what your selection will be.... signed Gerry from Virginia...

Well amigo Gerry, you should had added another element to your question and that one is how much money do you have for the antenna project, how high your budget may go......

Assuming a reasonable budget... I will install one 15 to 20 meters high tower, and two 15 meters high masts. Then at the top of the tower, I will install a 10 element log periodic antenna for the frequency range between 13 and 30 megaHertz... This log periodic may be made mostly of wire to reduce its weight... The other antennas will include half wave slopers for 40 meters from one the masts to ground and a full size fan dipole of at least 35 meters length...Once you have the tower and the three masts, you can continue installing other antennas, like a broadband TTFD or tilted terminated folded dipole , sloping from the tower.... As you have just heard, installing the log periodic antenna with a heavy duty rotor will allow you to operate your amateur radio station on the 20, 17, 15, 12 and 10 meter bands , that's five bands, and also monitor international short wave broadcasts on the 22, 19, 16, 13 and 11 meter bands...

although nowadays you will very rarely be able to pick up stations operating on the 25 megaHertz or 11 meters international short wave broadcast band., because at the bottom of the solar cycle broadcasters don't schedule transmissions on that band at all....

Then install several wire antennas, especially the broadband five wires per leg FAN DIPOLE that will give coverage to at least 80, 40, and 30 meters, providing an additional alternate antenna for the 20 , 17 and 15

meters bands...

Also consider that my 14 meters long TTFD antenna design works nicely from 7 to 35 megaHertz, and is fairly easy to homebrew at low cost, especially if you don't plan to run high transmitter power ...It is an excellent broadband antenna to install anywere.

Need antenna help, need antenna advice... just type in an e-mail to arnie@rhc.cu, again arnie@rhc.cu and I will be very happy to answer all your antenna and radios related hobby questions... send mail to arnie@rhc.cu, again arnie@rhc.cu, or VIA AIR MAIL to Arnie Coro , Radio Havana Cuba, Havana, Cuba And now just before going QRT, as always at the end of the show here is our exclusive and not copyrighted HF plus low band VHF propagation update and forecast... Solar activity is at a very low level indeed, solar flux at 70 units, very near the minimum baseline activity, there are absolutely no threats of solar flares, and ionospheric absorption expected to be also at very low levels... The effective sunspot number at around noon Saturday was 09 unitsO, and the A index was at the slightly unsettled level of 13 at the time that I was finishing writing this script, at around 2 thirty pm local time, that is 18 hours thirty UTC.. Expect nice transequatorial 6 and 10 meter band propagation during late local afternoon local time in Mexico, Central America, and the southern USA amigos. Hope to have you all listening to the mid week edition of Dxers Unlimited, Tuesday and Wednesday UTC days, and don't forget to send your signal reports and comments about the program to arnie@rhc.cu or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba ---[Start Commercial]---------------------