Monday, June 25, 2018

DXers Unlimited - weekend edition, June 24, 2018

Radio Havana Cuba
Dxer’s Unlimited -weekend edition, Sunday 24 June 2018
By Arnie Coro CO2KK

Hola amigos radioaficionados … you are now listening to the weekend edition of DXers Unlimited, when the sun has awoken, and for the first time in months  we saw more than two active sunspots regions looking towards planet Earth.

The news of the day, was that on the twenty first of June an amazing six meters band opening made possible for two Cuban radio amateurs to establish two way contacts on six meters with Japan... CO8LY in Santiago de Cuba and CM2XN in Havana enjoyed the nice band opening that happened from about twenty one hours forty to twenty hours fifteen UTC. The same band opening was enjoyed by amateurs in the Caribbean and North America too. It is solar minimum for sure, but this upsurge in solar activity is under close scrutiny by heliophysicists  the astronomers that specialize in studying the Sun.

This is Radio Havana Cuba and we are broadcasting in English to North America and Western Europe on 15140 kilohertz from fifteen to sixteen hours UTC,  using one of our 100 kilowatt transmitters.

Si amigos, yes my friends, we always find out new ways of making our own station and antennas accessories at low cost, like in the case of the non inductive terminating resistors using the TO dash 220 case configurations described in our last weekend Dxers Unlimited show. Good feedback from several listeners that have already assembled the easy to make dummy load using the new
ceramic high dissipation resistors in the TO 220 format package

Item two: Solar activity moved to moderate for the first time in a loooong time. Participating in HF amateur radio contests is one of the more than 90 ways that you can enjoy this wonderful hobby. But one thing is to participate and quite a different thing is finding yourself at the list of the TOP TEN winners of one of the world's most important contests.

It does take a high degree of skills to work as many stations as possible and acquire the multipliers used by a particular contest, plus also a lot of luck too. True you can run a very modest station and simple antennas and still make it a very enjoyable weekend by taking part in a contest...but again finding yourself among the winners is quite a different story.

I suggest that you can  join a group of radio amateurs that regularly take part in contests and benefit from their know how and expertise .Believe me amigos, learning how to operate during a contest is

A good ear for picking up CW is essential if you want to be a winner .... and that takes a long time
For example, you will find out that ... keyboard skills are essential if you want to achieve a good performance on any of the digital non automatic modes contests that are now so popular.

For the JT and FT8 modes you can still depend on a finger by finger action on the keyboard ! And I may add that learning how to properly use your voice will be a great help when participating in a voice mode contest. It is now much in use to put on the air a recording calling CQ Contest, in order to save the operators from a sore throat caused by excessive use of CQ calls in real time.The computer audio files won't get tired !

Si amigos, yes my friends, oui mes amis,  I do insist amateur contests are a great opportunity
to polish your operating skills and also for adding many new prefixes of rare DX entities that will be on the air during the contest periods...And you will sharpen your skills to communicate under difficult circumstances, a valuable asset during emergencies

Now another radio hobby related item here at the  weekend edition of Dxers Unlimited. Si amigos, sure you have just heard our classic interval signal ... this is Radio Havana Cuba and here is radio hobby related information for your enjoyment. the summer Sporadic E layer season is now in full swing as we move just past the summer solstice on the twenty first day of June.

My personal observations on Wednesday late afternoon and early evening brought several signals on the FM broadcast band that were clearly identified as reaching my receivers via Sporadic E clouds
located above the middle of the Gulf of Mexico. FM broadcast band Dxing requires a sharp tuning
receiver with high selectivity so that you can pick up stations on frequencies that are very close to the
local stations. 

By the way for listeners in the USA, Canada, Mexico, Central America and the Caribbean, here are several of the city of Havana FM stations and their frequencies...
Radio Progreso is on 90.3 megahertz ,
Radio COCO on 91.7 megahertz, Radio Rebelde is running high effective radiated power on 96.7 megahertz.
From Mayabeque province comes a powerful signal on 104. 7 meghertz from a transmitter located at the City of Havana's main TV and FM tower, built way back in 1956 with a height of very near two hundred meters, making it the nation's second highest structure used for broadcasting TV channels from 2 to 13 and from 14 to 51, plus FM stations within the 88 to 108 megahertz band.

By the way Cuban FM stations operate using vertical or circular polarization for reaching its audience using portable radios , cellphones capable of pickings up the FM band, and car radios

Here is now ASK ARNIE, la número uno , the most popular section of Dxers Unlimited , closely followed by the HF plus low band VHF propagation updates presented whenever possible at the end of the show....

Here is now, today's question sent by listener Mario from Mérida, Yucatan, Mexico. He says that is now learning about AM Broadcast band Dxing , after having spent more than 15 years scanning
the short wave bands and logging many of the international broadcast stations that are no longer on the airwaves.

Mario wants to know why signals on the AM medium wave broadcast band stations cover only a very limited area around the station during the daytime, but reach far away places as soon as the Sun sets...
Well amigo Mario, during the daytime hours at a given location the solar radiation keeps the D layer of the ionosphere at high levels of ionization that stop the lower frequencies from reaching the upper layers of the ionosphere...

The D layer is detected by the ionosphere sounders at altitudes between 50 and 70 kilometers above the surface of the Earth. The same ionosphere radar sets, known as ionosounders see how the D layer vanishes as soon as the sun sets, making it possible for the AM stations signals to reach the E layer of the ionosphere that act as a reflector of sorts, that makes possible single hop E layer signals to travel up to around two thousand kilometers.... So amigo Mario this is what actually happens and why your AM dial fills up with DX stations after sunset and until about one hour after local sunrise

Si amigos, this is the weekend edition of DXers Unlimited our e mail address is inforhc@enet,cu, and yes, we do reply immediately to your signal reports, comments and radio hobby related questions...

I do hope to see you all at the middle of the week edition of DXers Unlimited on the air Tuesday and Monday UTC days.

Send your signal reports and comments  via airmail to: Arnie Coro, Radio Havana Cuba, Havana, Cuba
(Arnie Coro)