Radio Habana Cuba: Dxers Unlimited Weekend edition for February 3, 2001
By Arnie Coro, radio amateur CO2KK
Hi, amigos! Welcome to the weekend edition of your favorite radio hobby show. I am Arnie Coro, radio amateur CO2KK, the host of this twice-weekly program devoted entirely to the promotion and development of this wonderful hobby you and I enjoy so much... RADIO!
Item one: had a bad case of the flu this week; that's why you heard a previously taped show during the mid-week edition slot, just could not tape the program with the raspy-sounding voice... Now it's better, so here we are again with the most up-to-date HF propagation forecasts at the end of the show...
The headlines: Oscar 40 satellite in deep trouble... seems like its Keplerian coordinates are such that the satellite is almost reaching what is known among space experts as escape velocity. More about this and other aspects of the OSCAR 40 satellite saga later...
Headline number two: Coronal Mass Ejection has sent charged particles toward Earth that may reach the magnetosphere as soon as Sunday UTC day... expect possible HF communications links disruptions at higher latitudes...
Headline number three: lots of feedback from Dxers Unlimited's listeners requesting so many things, and making so many suggestions I think I must ask for about at least ten more minutes of air time for the show!
Headline number four: Expect a very nice spring equinox DX propagation season... the 10, 12 and 15 meters amateur bands will provide many hours of enjoyment starting in about 20 days from today!
All this and maybe more, right here on this same Radio Havana Cuba short wave frequency you are now tuned to. Stay with me, I'll be back in a few seconds. Margarita Delgado is my sound engineer and producer, I am Arnie Coro in Havana...
You are listening to Dxers Unlimited's weekend edition... Oscar 40, the amateur radio satellite continues to make the headlines. It is now almost certain that the satellite will never reach its planned orbit, and that its lifetime cannot be calculated at all. Ground control stations seem to know a lot more about the satellite's actual health than what they are making public to all of us, something that is certainly not going to be very helpful for any future attempt to build and place in orbit a similar high-tech amateur satellite.
Now, the analysis of the satellite's Keplerian coordinates shows that at one particular point of its present orbit, the spacecraft is almost reaching what is known among space experts as escape velocity; that is, enough speed to be ejected away from the Earth's orbit. So the handling of the satellite's paremeters is becoming a very, very delicate matter, as any maneouver may boost its speed beyond the eleven kilometers per second that is the transition from an object in Earth orbit to an object going away into open space. There are more problems with the Oscar 40 spacecraft, of course, as it is now evident that some kind of explosion did ocur when the main engine was fired, causing irreparable damage to several of the vital onboard systems. Now, it is a matter of just watching what's going to happen, but I think that the Oscar 40 satellite designers and operators owe the worldwide amateur radio community a lot of information regarding the spacecraft. Keeping it from the public is certainly not the right thing to do!
Now item two: 10 meters was wide open Saturday morning. Just before I started to write this script, the solar flux level around 160 to 170 units was certainly helping the band to provide excellent two-way contacts, even while running low power. Here in Havana propagation was good in many directions, including Europe and Africa at around 16 hours UTC, that is, 11 AM local time.
Item three: Arnie, talk a bit more about Short Wave Listening... there are many of us who do not have an amateur radio station yet, and others who do have a nice time SWLing, too.... signed, a friend from Ohio.
OK, amigo -- I'll please you and others as often as possible, but don't expect from Dxers Unlimited long lists of stations that the average short wave listener can't read at 300 words per minute, in an endless monologue full of criticism of each an every broadcaster around the world....
So, ready for an SWL section of the show? Here we go! Monitoring the 13 meter band nowadays is an interesting experience for short wave listeners. The 21 megaHertz band is open to one part of the world or another for many hours every day, but it is still very much underused. Talking with senior international short wave broadcast station engineers and managers in the past, I have found there is a generalized opinion that 13 meters is not a popular band among the world's short wave listeners. Another rather generalized opinion is that 13 meters is not very reliable; in other words, managers and engineers prefer to operate whatever transmitters are available on lower frequencies that are not so much dependent on daily maximum useable frequency variations... and last but not least, stations using older equipment prefer to operate them on lower bands, as it is a fact of life that high power short wave equipment operating on the 21 and 25 megaHertz bands -- 13 and 11 meters -- is more prone to technical problems than when it is operating on lower frequencies...
Nevertheless, I think that 21 megaHertz is an excellent choice for many long range propagation paths, and that today's receivers, even the lower cost portables, perform rather well on both 13 and 11 meters. Due to the much lower ionospheric absorption on these two higher HF bands, excellent results can be achieved with less transmitter power, and the antennas for the two bands can be built at rather low cost, too... So maybe it's about time that all those involved in frequency planning make it a point to use both 13 and 11 meters more, for the enjoyment of the world's short wave listeners.
Scan 13 meters from as early as sunrise to as late as several hours past sunset, and keep a log of what you are picking up. Start listening on 21.455 and move slowly up; try to identify each station as you scan the band. As we approach the spring equinoctial DX season, 13 meters will provide many hours of nice, high-quality short wave listening, even with a small receiving antenna!
Remember, start scanning very slowly just above the 15 meter amateur band, on 21.455 kiloHertz and move slowly up... it may also be a good idea to monitor the 15 meter ham band, from 21.2 to 21.4 megaHertz for signs of DX activity on SSB. As a matter of fact, radio amateurs use the 13 meter band broadcast stations as indicator beacons of DX propagation on 15 meters, as the bands are just right next to each other!
Another new section here at Dxers Unlimited? Well, YES, absolutely! Anything we can do to improve the show is done as soon as possible, and at the request of many listeners, here is the first installment of the HOMEBREWERS' CORNER, a section that will surely become extremely popular very soon, as more and more radio enthusiasts are enjoying homebrewing of radio equipment and antennas these days.
HOMEBRWERS CORNER today will tell you more about homebrew frequency converters that can extend your receiver's coverage, and in the case of older radios, make them work as dual conversion receivers. A converter is a very simple and logical gadget -- typically it has a bandpass filter at the input, a radio frequency amplifier stage, a mixer and a local oscillator. Using a quartz crystal for controlling the frequency of the local oscillator, the converter allows its user to tune a segment of the radio frequency spectrum with a receiver tuned to typically a lower frequency band. Here is an example: A converter built to tune from 50 to 52 megahertz, the first two megahertz of the 6 meter amateur band, uses a quartz crystal oscillator resonant to 45 megahertz, so its output is a signal in the frequency range from 5 to 7 megahertz that can be picked up by any receiver able to tune to that lower frequency range.
Building frequency converters is a lot of fun; you are actually building the front end of a receiver, so you learn a lot about receiver construction techniques. The now popular REGENERODYNE receiver uses a crystal-controlled converter that feeds a variable frequency regenerative detector, a combination that is hard to beat for simplicity and performance! More about homebrew frequency converters will be heard during the upcoming mid-week edition of Dxers Unlimited next Tuesday and Wednesday UTC days.
And now, just before going QRT, here is, as always at the end of the show, Arnie Coro's Dxers Unlimited's HF plus 6 meters propagation update and forecast... Solar flux is hovering around 160 to 170 units and moving slowly up; expect a possible high latitude geomagnetic disturbance during the next 48 hours, during which Dxers Unlimited's listeners living above 40 degrees North latitude will be able to pick up some very interesting Medium Wave band DX stations from locations South of you. The actual number of Sunspots counted on Saturday was 109, down from Friday's count of 124. The highest registered maximum useable frequency that was propagating Saturday between 15 and 17 UTC was around 40 megahertz, as detected by the ionospheric forward mode sounders, also known as chirp sounders.
For short wave listeners, the 13 and 16 meter bands will provide excellent reception until sometime past local sunset, and amateur radio operators can be sure of finding nice DX while running low power when you wake up Sunday morning and tune to the 10 meter band.
Don't forget to send your signal reports and comments to arnie@radiohc.org and via Air Mail to Arnie Coro, Radio Havana Cuba, Havana, Cuba.
See you next Tuesday and Wednesday UTC days at the mid week edition of the show, and if you are already on the air with you amateur radio station, let's have a nice chat around 28.5 megahertz, 28.500... like the nice chat that Bob VE3SRE and I had a few days ago! That was a wonderful two-way ham radio contact, amigos... Go ahead and study for your amateur radio license test... you will always enjoy this wonderful aspect of the radio hobby!
prepared 3-Feb-2001; transmitted 6-Feb-2001
Arnie Coro CO2KK
Havana, Cuba
February 3, 2001Postal address:
Arnie Coro, "Dxers Unlimited"
Radio Havana Cuba, Havana, CUBA
e-mail: arnie@radiohc.org
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