DXERS UNLIMITED
WEEKEND EDITION
SATURDAY, AUGUST 25, 2001
By Arnie Coro CO2KK
Send your comments, questions and ideas to: arnie@radiohc.org
Hi, amigos RADIOAFICIONADOS around the world! Welcome to the weekend edition of your favorite radio hobby program It's nice to share with you about 17 minutes of air time, my friends! I am Arnie Coro, radio amateur CO2KK your friend in Havana, and host of this twice-weekly program that I hope you will enjoy!!!
Item one: Solar activity moving UP, the transition from summer to
equinoctial propagation conditions is already taking place, so expect much
better HF DX starting this week...
Item two: The list expands... Yes, we have now registered 67 different ways you and I can enjoy our wonderful hobby, so from now on, you will hear the more than SIXTY WAYS radio can make you spend a nice time... Here is one of the latest additions: SLOW SCAN TELEVISION on the Low Frequency Bands... quite an achievement by those who have done it, because the LOW FREQUENCY antennas have usually a very narrow bandwidth... By the way, the relatively new software for Slow Scan TV from Japan, MMSSTV, is gaining popularity among those that enjoy sending and receiving slow scan TV signals...
Here in Havana, when the Hurricane season is in full swing, radio amateurs gather on a 2 meter band hurricane watch net, and among the very interesting information they exchange, you will find satellite pictures moving back and forth using the MMSSTV software. More about MMSSTV and how to setup your computer and radio to pick up slow scan TV pictures later in today's edition of Dxers Unlimited!
I'll also tell you more about the ONE PLUS ONE ultra simple amateur bands transmitter, will answer a question sent in by a listener wanting to know more about the HALF SQUARE antenna, and as always, at the end of the show Arnie Coro's Dxers Unlimited's HF propagation update and forecast will provide the most up to date information that will guide you to the best possible enjoyment of that aspect of our wonderful hobby.
Stay tuned right on this same Radio Havana Cuba frequency, Margarita Delgado is my sound engineer and producer at RHC studio 7. I am Arnie Coro in Havana, back with you in a few seconds amigos!
According to the latest information circulating via the INTERNET, there are several excellent short wave portable radios now available at reduced prices, so look around as this may be your opportunity to buy a new portable, always a worthwhile addition to one's shack... By the way, my faithful SONY ICF7600 digital radio just broke down Tuesday, and so far, all my efforts to bring it back to life have failed... And while attempting to repair the sophisticated microprocessor-controlled receiver, I was happily listening to a short wave broadcast from Spain, via the nearby Costa Rica relay station of Radio Exterior de Espana, on my little nice 3 tube regenerodyne...
A neighbor came in looking for me when I was at the workbench, trying to find out what was wrong with the digital dial receiver, and he asked what kind of radio was that one he was listening to, as it sounded very good to him... I then took a little time away from the so-far failed repair job, and showed Francisco the 3 tube regenerodyne set... Well to make it short, he came in to ask me to solder a coaxial connector for his VCR machine, and he left with the connector properly soldered to the coaxial cable, PLUS the circuit diagram of the REGENERODYNE, and a few parts to start up, because YES AMIGOS, it has happened time and again, everytime that someone comes into my shack and listens to that radio, they always want to learn more about it.
You can see the actual circuit diagram of the 3 tube REGENERODYNE just by sending an e-mail to arnie@radiohc.org, or a postcard via AIRMAIL to Arnie Coro, Radio Havana Cuba, Havana, Cuba... Ask for the REGENERODYNE receiver INFO PACKAGE and I will send you some more circuit diagrams of other regenerodyne receivers... Well, as of Saturday morning, Francisco has almost finished collecting the parts for his radio, so in a few days' time, yet another REGENERODYNE will be picking up signals!!!
Let's hope that I can find what's wrong with the SONY ICF7600 Digital before Francisco has his REGENERODYNE picking up short wave signals!!! And yes amigos, that is one of the advantages of homebrew radio equipment... 99.99 percent of the time, you can fix it all by yourself, something that unfortunately is not the case with the newer generation of digital solid state equipment!!!
Ah, and before I forget, do not attempt to open up a modern digital solid state receiver or transceiver without the manufacturer's workshop repair manual right next to you...some of those newer radios have very special ways of disassembling that, if not followed, can result in permanent damage to the set!!! HOMEBREW, SWEET HOMEBREW I should say ... right???
You have questions? Well amigos, if you have any radio hobby-related question just ask and I'll be more than happy to answer directly to you via e-mail or an AIR MAIL letter, and in many instances, right here, on the AIR and on the WEB...
Today's question came from a Dxers Unlimited's fan in India... Yes, he picks up the scripts via our majordomo mail distribution list, and on rare occasions he can pick up our 9820 kHz frequency beamed to the Pacific coast of North America via terminator line, or gray line propagation... Also our friend in India tells me that our European broadcast on 13750 kiloHertz is also sometimes heard in Asia... Well, here is today's question:
Arnie, can i use a scaled up version of the 2 meter band HALF SQUARE for the ten meter or fifteen meter amateur bands???
Absolutely amigo, but be aware that the HALF SQUARE is a single band antenna... it is not a broadband antenna system at all; you will have to install one HALF SQUARE for the 21 megaHertz or 15 meter band and another one for the 28 megaHertz or 10 meter band... Also, very important, the two antennas should be well separated from each other, in order to reduce interaction between the two antennas to a minimum... And, amigo Rajid, I must add that the HALF SQUARE for the HF amateur bands is an amazing antenna system to say the least... Just ask my good friend Bob Chandler VE3SRE, who has used the HALF SQUARES at his contest station in a remote part of Canada with great success...
Just remember the basic figures: The vertical elements should be around 0.28 wavelength high, and the horizontal single wire transmission line should be around 0.94 wavelength long. The antenna MUST be fed using 50 ohm coaxial cable, and the use of a coaxial choke balun at the feedpoint is vitally important in order to obtain a clean vertical radiation pattern, and please don't forget, amigo Rajid, to hang the Half Squares in such a way that the coaxial feedline goes away from the elements at least one quarter of a wavelength horizontally before it turns towards the shack!!! Si amigos, oui mes amis, yes my friends, the HALF SQUARE vertically polarized two element antenna system is really one of those wonderful performing simple antennas!!!
And now amigos as always, at the end of the show, here is Arnie Coro's exclusive Dxers Unlimited's HF plus 6 meters propagation update and forecast....
Solar flux was near 190 units and the effective sunspot number was at around 130, with the 3000 kilometer F2 layer MUF going already as high as almost 40 megaHertz on North, South paths, so if you are already an amateur radio operator, fire up your 10 meter band rig and look for DX... it is very likely to be there just waiting for you... A description of the most recent solar events, in a scientific language format follows:
SUNSPOT ALERT: Fast-growing sunspot group AR9591 now covers a region of the Sun equivalent to the total surface area of four planet Earths. Furthermore, the large spot is surrounded by a tangled delta-class magnetic field that probably harbors energy for powerful X-class solar flares. Eruptions that happen today wouldn't likely be Earth-directed because the sunspot is near the Sun's southeastern limb. But the threat of Earth-directed explosions will increase in the days ahead as AR9591 rotates toward the Sun's central meridian....
That's it amigos, in plain language: The SUN is very active, and solar cycle
number 23 continues to puzzle scientists with its rather broad and very slow
descending peak, plus the fact that it already produced the huge X26 type
flare, the largest X ray event ever recorded by man!!! Again, VHF operators
be on the alert, for possible Aurora Borealis E skip on 6 and 2 meters, and
F2 layer propagation on 6 meters.
Arnie Coro CO2KK
Havana, Cuba
August 25, 2001
Postal address:
Arnie Coro, "Dxers Unlimited"
Radio Havana Cuba, Havana, CUBA
e-mail: arnie@radiohc.org
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