Radio Havana Cuba
Radio Havana Cuba's Dxers Unlimited weekend edition for 17-18 Nov 2007
By Arnie Coro, 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, as by 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 MHz , 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: A 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@rhc.cu , again, arnie@rhc.cu, 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@rhc.cu, 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 ban 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 kHz.
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 kHz up the band...
Radio Havana Cuba's Dxers Unlimited weekend edition for 17-18 Nov 2007
By Arnie Coro, 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, as by 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 MHz , 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: A 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@rhc.cu , again, arnie@rhc.cu, 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@rhc.cu, 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 ban 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 kHz.
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 kHz up the band...
And if propagation conditions are really good, 60 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@rhc.cu , 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.
Now here is the next item of today's program: The most popular section of Dxers Unlimited... LA NUMERO UNO.. ASK ARNIE... answering your radio hobby related questions on the air and also sending a written reply via e-mail and VIA AIR MAIL too if you send me your postal mailing address included in your e-mail message... Today's question came from Canada.., once again fighting against man made interference is the topic of a question sent to Dxers Unlimited. Amigo Gerard from Laval, Quebec, wants to know it is true or not that so called magnetic loop antennas can help to reduce radio noise picked up at downtown locations where lots of appliances are operating at the same time , especially desktop computers... Well amigo Gerard , the answer is YES, even a very easy to homebrew receive only magnetic loop, built with a length of RG213 coaxial cable and an air spaced variable capacitor will improve your reception a lot, because the magnetic loop can be turned easily to cancel the worst local noise sources...
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@rhc.cu , or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba.
.......
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@rhc.cu , 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.
Now here is the next item of today's program: The most popular section of Dxers Unlimited... LA NUMERO UNO.. ASK ARNIE... answering your radio hobby related questions on the air and also sending a written reply via e-mail and VIA AIR MAIL too if you send me your postal mailing address included in your e-mail message... Today's question came from Canada.., once again fighting against man made interference is the topic of a question sent to Dxers Unlimited. Amigo Gerard from Laval, Quebec, wants to know it is true or not that so called magnetic loop antennas can help to reduce radio noise picked up at downtown locations where lots of appliances are operating at the same time , especially desktop computers... Well amigo Gerard , the answer is YES, even a very easy to homebrew receive only magnetic loop, built with a length of RG213 coaxial cable and an air spaced variable capacitor will improve your reception a lot, because the magnetic loop can be turned easily to cancel the worst local noise sources...
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@rhc.cu , or VIA AIR MAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba.