Sunday, June 03, 2018

Dxers Unlimited's weekend edition for Sunday June 3 2018


Radio Havana Cuba

Dxers Unlimited's weekend edition for Sunday June 3 2018 By Arnie Coro radio amateur CO2KK

Hola amigos... its really nice to have the opportunity of sharing with you about ten minutes of all radio hobby related information. I am your host Arnaldo, Arnie, Coro, radio amateur CO2KK  at the microphone, and here is item one of this show.
Several days in a row with at least one sunspots active region have had a positive effect on the levels of ionization, with the solar flux moving up to around 75 units... Nevertheless we continue to go through the tail end of solar cycle 24, the weakest one since mankind began to use radio waves for communications....

This is Dxers Unlimited's weekend edition coming to you from Havana, the capital city of Cuba.... Now item two: The history of radio is fascinating... every country in the world uses radio broadcasting facilities of some type, to provide vital services to its population.
Many of those sites are now part of the world's heritage.
Some of those facilities involve extremely complex engineering , using a lot of electricity to power up transmitters and having to perform regular expensive maintenance work.
In Europe we find a very interesting story around the so called Warsaw , Poland, radio mast, that when it went into operation on May 18 of 1974 for long wave AM band transmissions  as it was certified to be the tallest man made construction ever built.
The two one thousand kilowatts Brown Boveri transmitters operated in parallel to feed the huge tower with two thousand kilowatts of one hundred percent modulated long wave signals at first on 227 kiloHertz and at a latter date on 225 kiloHertz.
The huge steel structure  collapsed on August 8, 1991 due to a mistake by the crew doing maitenance work changing one of the the guy wire on the highest part of the structure.
Designed by  polish engineer Jan Polak, its height of 2,120.7 feet , that is equivalent to 646 dot 38 meters and it was chosen in order to make the mast function as a half-wavelength vertical radiator antenna, fed at the bottom,  a design parameter that was widely critiziced because of the radio frequency current distribution along the tall mast at the broadcasting frequency.

Located in Gabin, Poland, it was the world's tallest structure until August 8th 1991 when an error was made in exchanging the guy-wire on the highest part and that led to its collapse. Witnesses say it bent first then snapped at roughly half height.
During the solar minimum years , the Polish Long Wave Super High Power
225 kiloHertz AM broadcast signal could be heard half way around the world, due to the prevalent very low ionospheric absorption, typical of the solar minimum years..

Si amigos, although the Long wave AM broadcast facilities are closing down as a logical consequence of the expansion of FM and digital transmissions , plus the extremely high operating costs of the super power transmitters used at those stations, at least a few of them will probably remain on the air until the transmitting equipment life time comes to an end....
But, let me add that AM Medium Wave and AM Long wave transmitting facilities using the solid state technology will probably enjoy a lifetime well into the middle of this century....
So, Dxing on the Long wave and Medium wave AM bands will provide many more years of enjoyment, especially after 2020 when solar cycle 24 comes to an end...

The radio hobby is fully enjoyed by people with poor eyesight or totally blind... And now the availability of screen characters to voice generators is making possible for blind persons to use the digital communications modes, like PSK31, PSK63, MFSK, and the more recent JT 65 and FT 8 modes...On Thursday I received an air mail letter from radio amateu Charles Von Sant, callsign K9HIO that I would like to share with Dxers Unlimited's listeners... Charles , who live in Lawrenceburg, Indiana says he has listened to Radio Havana Cuba broadcasts for many years, finding our transmissions interesting to him He adds that he is helping an audio reading service by radio run by the Cincinnnati Association for the blind and visually impaired persons.The service is provided 24 hours a day on a sub carrier of station WGUC-FM 90,9 megaHertz FM, that operates on 67 kiloHertz. Charles add that the group provides users with receiving adapters that decode the sub carrier.
He adds that they are always looking for interesting radio programs, and that he would like to start up broadcasting a program similar to Dxers Unlimited...
Amigo Charles I wish you good luck with that project to provide a radio hobby program as part of the services to blind persons , and you can count on us for any help of advice needed....

Here in Cuba there are many blind persons that are licensed radio amateurs, having passed the Ministry of Communications tests required to obtain a license to operate their own amateur radio stations.

This is Radio Havana Cuba broadcasting via satellite on Hispasat I D transponder 79 vertical polarization, that has a nice footprint making reception possible at many locations in the USA and Canada, as well as over most of the Caribbean...
We are also on the streaming audio service from www.radiohc.cu And now here is one of Dxers Unlimited's most popular sections.... A visit to Arnie Coro's radio and electronics workshop. Si amigos, with just a few handtools, a soldering iron and a digital multimeter you can start to make your own workshop, where simple projects may be built, and also repairs could be made to electrical appliances and electronic equipment. I am not saying that you can find and fix complex faults, but you can certainly repair a desoldered audio plug, or build a simple reverse polarity protection device that will prevent damages done to electronic equipment when an external power supply is connected with the polarity reversed...
SI amigos, yes my friends, you can learn a lot about this wonderful hobby by reading tutorials devoted to teaching how to solder electronic equipment, how to follow a circuit diagram, and last but not least how to slowly go through the learning curve that makes possible to do more sophisticated homebrewing of radios and accesories ...

Amazing as it may sound, two meters band FM hand held transceivers are now available from many suppliers at rock bottom prices, and some ot those gems are also capable of operating on the 70 centimeters amateur band....Connecting one those FM transceivers now sold in many countries for less than 75 dollars or its equivalent, to an external antenna will make possible to communicate at much longer distances and establish links using the 2 meters and 70 centimeter bands repeaters.... The availability of this new generation of low cost handy talkies for the 2 meters and 70 centimeters band makes possible to enjoy amateur radio at a start up level without having to spend a lot of money.... phase two will be to learn how to build your first QRP transceiver kit, and go on the air on one of the HF amateur bands...

Listen next Tuesday and Wednesday UTC days, after the half hour news bulletin to the middle of the week edition of Dxers Unlimited, and set aside a little time to send me a signal report and comments about today's show... send mail to inforhc at enet dot cu, and Via Air Mail to Arnie Coro, Radio Havana Cuba, Havana, Cuba...
(Arnie Coro/Radio Havana Cuba)