Radio Habana Cuba: Dxers Unlimited weekend edition for March 3, 2001
By Arnie Coro, radio amateur CO2KK
HI! Welcome to the weekend edition of Dxers Unlimited, your favorite radio hobby show! I am Arnie Coro, radio amateur CO2KK, your friend in Havana and host of this twice weekly program that features the most up-to-date High Frequency propagation updates and forecasts, answers to your radio hobby related questions, and that very special emphasis on the technical aspects of this technical hobby!
NOW the headlines for today: Solar activity hits rock bottom low with only 88 sunspots visible... lowest number in many weeks and NOW, amigos, it is more and more in the clear... if something really outstanding and unpredictable doesn't happen, solar scientists are about 90 percent sure that SOLAR MAXIMUM FOR CYCLE 23 is NOW history! The more skeptical astrophysicists want to wait for a few more weeks before declaring cycle 23 as entering its downward journey towards solar minimum.... but, after a careful analysis of the Sun's magnetic field, and statistical analysis of solar activity during the past thirteen months, it will take an extraordinary upsurge in solar activity to generate a second solar maximum, something that MAY HAPPEN, as it did during cycle 22, when after the 1989 maximum and a pronounced dip in 1990, the Sun came back to produce a second maximum during 1991!
Item two: Another ham radio contest in progress during this weekend, it is an SSB voice contest, so if you have a receiver that is capable of picking up single sideband signals, monitoring the amateur bands will bring lots of interesting DX stations that are active during the contest.
Item three: More Dxers Unlimited's listeners are enjoying building their own radio equipment with the help or our circuit diagrams. Some listeners are actually improving and modifying circuits, or adapting them to the electronic components that are available... One outstanding example, a solid state version of the REGENERODYNE receiver, is now in the works, using both bipolar silicon transistors and metal oxide semiconductors field effect transistors, plus an integrated circuit audio amplifier... More about the solid state version of the REGENERODYNE coming up later in today's edition of Dxers Unlimited... and as always, at the end of the show you will be able to hear Arnie Coro's exclusive and not copyrighted HF plus 6 meters propagation update and forecast.
The name of the station is Radio Havana Cuba, this is Dxers Unlimited, our twice-weekly program devoted to the promotion and development of the radio hobby in all of its more than 50 ways that you and I can enjoy it...
Here is is item three: After building not one, not two, but three REGENERODYNE receivers, it is now clear that the original designs using vacuum tubes as active devices performed very nicely... but, as expected, they do require filament power, and a high voltage power supply for the vacuum tubes' anodes and screen grids... Then, a listener wrote and I quote, Arnie, why don't we go ahead and try to design a solid state version of the REGENERODYNE receiver? -- something I thought was a very good idea. Well now, after about two weeks, the front end of the prototype solid state version of the hybrid receiver that uses a regenerative solid state detector is almost finished. As a matter of fact, I am feeding the experimental front end's output to my R250M2 Professional Communications receiver, and the solid state front end is working nicely... This is what it is doing: Picking up signals in the frequency range from 15 to 18 megaHertz, and converting them to the two to five megaHertz range -- that's where the new solid state Dual Gate MOSFET regenerative detector, yet to be built, will operate. The experimental solid state front end for the REGNERODYNE uses very common bipolar NPN silicon transistors, so that the parts needed for building yours can be easily found. I borrowed some excellent design ideas from Jim Kortge, K8IQY, a QRP or low power enthusiast who has designed a number of simple amateur transceivers intended for home construction... The new solid state front end uses a tuneable input bandpass filter, an attenuator, and the active radio frequency amplifier stage, which feeds a broadband double balanced diode mixer. A crystal controlled oscillator operating at 12 megaHertz completes the front end.
So far, all tests show that the three bipolar NPN silicon transistor front end is working nicely... So we are now ready for phase two... building the dual gate MOSFET regenerative detector... If you want to start gathering information about the SOLID STATE REGENERODYNE, a complete detailed explanation on how the front end was designed and how it operates is now available, just drop me an e-mail to arnie@radiohc.org, and I will send you the text file with the complete step-by-step explanation of the solid state front end which, by the way, could be a nice addition to some of the cheaper small portable digital radios, which could benefit a lot by using this front end as a converter that will allow you to enjoy all the benefits of a double conversion receiver at very low cost! If you don't have access to e-mail, just drop me an AIR MAIL postcard to Arnie Coro, Radio Havana Cuba, Havana Cuba, and I will send you a printed copy of the UNIVERSAL SOLID STATE HF CONVERTER that you can build either to improve your present short wave receiver at low cost, or to use as the front end for the SOLID STATE REGENERODYNE!!!
You are listening to the weekend edition of Dxers Unlimited coming to you from Radio Havana Cuba... and now, here are a few DX tips for those of you who already have receivers capable of picking up single side band signals.... This amateur contest weekend will see a lot of interesting stations on the air that you can log as a short wave listener, or try to work them if you are already a licensed amateur radio operator. Here are but a few examples of the goodies on the air during this weekend...
From Samoa, operator Dominique will be operating using the callsign 5W0DA, that is five whisky zero delta alpha. Dominique plans to be in Samoa until next Tuesday, and then he will move to the South Cooks Islands, operating from Rarotonga, using the callsign ZK1EPY, that is zulu kilo one echo papa yankee in phonetics. Dominique's home callsign is F6EPY in France, and if you happen to pick up his Pacific DX operations, send him a QSL card to his home callbook address.
Another interesting catch during the SSB contest will be T48RAC, operating on the 40 and 20 meter bands only from the Santiago de Cuba Radio Club. T48RAC this year will devote its contest activity to training new contest operators for future events....
You can start to pick up DX stations on the ham bands at anytime during this weekend; just remember to tune to the higher bands during your local daylight hours, switching to 20, 40 and 80 meters at night.
arnie@radiohc.org is our e-mail address, and Via Air Mail, just send your postcards or letters with your signal reports, QRP requests and comments about this show to Arnie Coro, Radio Havana Cuba, Havana Cuba.
Now here is item four, our popular YOU HAVE QUESTIONS, and I try to answer them. Today's question came from a listener in Oregon, USA... he asks: Arnie,is it true that during geomagnetic disturbances at high latitudes one can pick up rare DX stations? Yes, that's correct -- high latitude geomagnetic disturbances, like the one that may possibly be affecting reception right now above 45 or 50 degrees North Latitude, usually create some very special propagation conditions that bring in rare DX from locations SOUTH of your QTH. This is particularly noticeable on the AM medium wave band, where Latin American and Caribbean stations are heard easily when the nearby locals almost disappear due to the effects of the geomagnetic disturbance. That's why I keep telling Dxers Unlimited's listeners that it is a good idea to monitor the bands whenever propagation forecasters announce an imminent disturbance... That's how I have worked quite a few outstanding DX expeditions and other rare DX stations in the past!!!
And now, amigos, as always at the end of the show, here is Arnie Coro's Dxers Unlimited's HF plus 6 meters propagation update and forecast... WARNING: A disappearing solar filament effect may be already affecting HF propagation at high latitudes... Be ready for possible Aurora Borealis VHF DX tonight and possibly tomorrow, too. For SIX METER band operators, this special advice: Keep your antennas beaming to the SOUTH, starting around four PM your local time, and do monitor 28.885 khz on 10 meters for any possible SIX METER OPENING ALERTS that may be made on 28,885 kiloHertz, the international six meter propagation coordination frequency.
For short wave listeners, especially for those of you who enjoy listening to news and entertainment via short wave during your local evening hours, the best bands for easy listening will be 49, 41 and 31 meters, that is the frequency range from approximately 5.9 to almost 10 megaHertz....
Don't forget to send your signal reports and comments about Dxers Unlimited, your radio hobby-related questions and any ideas you may have on how to improve this show. Radio is a great hobby, there are more than 50 ways you and I can have a good time with our radios, but we can make that time even better working together, amigos. See you after the contest is over on 14.2 megaHertz, and I will be operating also on 40 meters around 7060 kiloHertz, listening on frequencies above 7150 kiloHertz that I will announce when calling CQ there...
Remember, arnie@radiohc.org is your direct path to get in touch with us, and don't forget to visit our Dxers Unlimited website too!!!
prepared Mar-03-2001; transmitted Mar-05-2001 10:36 EST
Arnie Coro CO2KK
Havana, Cuba
March 3, 2001Postal address:
Arnie Coro, "Dxers Unlimited"
Radio Havana Cuba, Havana, CUBA
e-mail: arnie@radiohc.org
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