Radio Habana Cuba: Dxers Unlimited mid-week edition for 3 April, 2001
By Arnie Coro, radio amateur CO2KK
Hi amigos, WOW! What a flare! What a solar flare!!! This one could have really damaged quite a few satellites and even equipment located on Earth, had it happened when solar active region 9393 was right in the middle of the solar disk. BUT, the X17 -- yes, you heard it right -- an X flare that reached the 17 level, the second most powerful ever recorded, erupted when sunspot active region 9393 was almost at the edge of the solar disk, so most of the highly energetic particles were ejected into outer space and are not Earth bound.
Anyway, solar scientist are skeptical, and they are saying that we must wait and see what happens during the next two to three days, as a part of the matter ejected from the Sun at high speed may eventually reach the Earth... What the huge flare did produce immediately was a RADIATION STORM, and the classical short wave blackout was also observed just after the solar telescopes detected the huge eruption from super sunspot 9393.
According to highly respected solar researchers, there is now another active region, just emerging on the solar disk, that may produce X type flares, and as a matter of fact it already generated an X1 flare Tuesday morning local time here in Havana, something I could tell when my reception on the 19 meter international short wave broadcast band suffered severe attenuation.
Solar cycle 23 is going through a very active period indeed, and it is quite possible that we may see a second peak, something similar to what happened with cycle 22 in 1989 and 1991.
ITEM TWO: With such interesting solar events in progress, radio hobbyists are spending a lot of time spinning dials, or keying in numbers into digital receivers' keypads, and many of you have added quite a few interesting DX loggings to your records.
Here in Havana I monitored AM broadcast band stations from Brazil for several hours last Monday evening, and the Colombian stations that are heard here regularly had fantastic signals. I also have received reports of Radio Progresos 890 kiloHertz frequency heard in Canada with excellent signal during the geomagnetic storm that kept propagation conditions on the HF bands poor since late Saturday.
Item three: A reminder to those of you who enjoy reading the text version of Dxers Unlimited's scripts -- Danny our webmaster at RHC will soon configure the majordomo at our e-mail server, so you can send a request via e-mail to majordomo@rhc.cu with the message "subscribe dxers_l" and the scripts of Dxer's Unlimited will reach you automatically via e-mail. The list will be working real soon now. And, of course, they are also posted here at the Dxers Unlimited website.
You are listening to Radio Havana Cuba, this is Dxers Unlimited and here is item four: CO2OJ, my good friend Oscar Morales Jr., had done it again... Oscar made the first-ever QSO, or two-way amateur radio contact, using the new MFSK16 radio teletype keyboard-to-keyboard mode with a station in Florida, using the 2 meter band. Oscar's achievement followed the first-ever PSK31 contact some time ago, and he told us that the MFSK16 mode allowed reducing power to incredibly low levels.
At one point CO2OJ was having a two-way QSO on 2 meters MFSK16 while running only 200 milliwatts, with perfectly clear copy of all characters on screen. Remember last week when I played a tape here showing how the MFSK16 teletype mode sounded? Well, seems the way this new mode is designed to enhance communications is so effective that it will soon be the logical choice for VHF and UHF weak signal work. And as an added bonus, the MFSK16 system does not require a highly skilled operator, anyone how can type at a keyboard and operate a station could benefit from the fantastic weak signal efficiency of MFSK16.
And you can download both programs, PSK31 and the Windows "stream" program for MFSK16 right here at Dxers' Unlimited.
Congratulations Oscar, and keep up the good work on the VHF bands, amigo!!!
Dxers Unlimiteds mid-week edition brings you now item five: The very popular you have questions and Arnie Coro answers them! Here is today's first question: Arnie, the new version of the TTFD broadband antenna, the one you described some time ago that is about 14 meters long, that is about 45 feet long, will work OK from the 40 meter band up... true or false?
Well amigo, as you are asking me for a true or false answer, I must reply with a single word: TRUE! You are right the 14-meter, or 45-foot, long version of the TTFD with the new higher resistance terminating resistor of between 800 and 900 ohms, will provide excellent performance between 7 and 30 megaHertz. Again, just in case there was a little QSB... the new version of the TTFD is a nice broadband antenna for receiving between 7 and 30 megaHertz. It does require a 12 to 1 balun, if you want to feed the antenna with 75 ohm coaxial cable and, as always, I strongly recommend using the TTFD with a PI network antenna tuner. NOW, let me add this important bit of information: the new version of the TTFD will provide very good reception of the 49 meter international broadcast band, too. As the attenuation, compared with a regular full-size half-wave dipole at 6 megaHertz, should be about minus 6 dB or in other words minus one S unit... something that will go practically without noticing it, due to the fact that signals on the 49 meter band are usually very strong during your local nighttime hours.
So amigo from California... YES, you are right, the new TTFD will provide excellent broadband coverage from 6 to 30 megaHertz, but will be still better from 7 to 30 megaHertz. AND, you can also use it for transmitting with your ham radio equipment, IF -- and listen well, now, -- IF you make the terminating resistor large enough to be able to dissipate about 25 percent of your transmitting power in a worst-case situation. So, for a typical amateur 100-watt HF transceiver, a 25-watt non-inductive resistor of between 800 and 900 ohms will work very well!
NOW, here is another point of view: Some radio amateurs prefer to install a wideband fan dipole, feed it with open wire transmission line and connect it to a well-designed antenna tuner. The fact is that this is a far more efficient approach than the TTFD or Tilted Terminated Folded Dipole but, using the FAN BROADBAND DIPOLE in its 13.4 meters or 44-feet long version will require RETUNING the antenna tuner very often, something that is not necessary with the TTFD! So here you are amigo... Two simple antennas, one fully broadbanded that can work even without an antenna tuner, the other one also broadbanded but which does require an antenna tuner or otherwise won't work properly.
If you ask me which one I would install if I had space for just one antenna, here are my two answers: IF I was going to use the antenna just for receiving, I will surely go for the TTFFD, while if the antenna is to be used for both receiving and transmitting I will go for the 13.4 meters or 44 feet dipole, using 3 wires on each leg of the dipole to further enhance its broadband characteristics. And I hope that this will help you make up your mind amigo!!!!
Any more doubts, just e-mail them to arnie@radiohc.org or via Air Mail to Arnie Coro, Radio Havana Cuba, Havana Cuba.
Now here is item six at the mid-week edition of your favorite radio hobby show, answering a short question related to antennas, sent from Canada: Arnie, what's the best wire for a stealth antenna, my only option as a condominium dweller?
Well amigo, there is a very nice, but expensive, Teflon insulated wire, which has a black insulating jacket ideal for stealth antennas that can be lowered at night from a balcony using a rubber ball as a weight.
This is easily done using a fiberglass fishing rod that extends out about 2 meters, or a bit more. You unwind the Teflon wire from the fishing rod's reel, and then connect your feeder with a crocodile clip that will make contact with the copper wire. You will need an antenna tuner, of course, and experimenting with different wire lengths will take a little time until you find the best length for each band. Such a stealth antenna system works really well during the night, and my advice it to paint the rubber ball at the end of the wire with matt black paint, too. It's a good antenna, except when there is a lot of wind!!!
And now, at the end of the show, here is Arnie Coro's Dxers Unlimiteds HF plus 6 meters propagation update and forecast: HIGH solar activity may continue or switch down to MODERATE... Super Sunspot 9393 to rotate soon out of sight, but there is another solar region now developing that has already produced an X1 flare -- of course nothing that can be compared to the super X17.1 flare that made scientists at solar observatories jump when they saw their radiation measuring instruments jump off the scale... Expect high ionospheric absorption for the next 48 hours, possible F2 very high maximum frequencies reaching past 50 megaHertz, and yet another geomagnetic storm may develop this week, too...
The 10 and 6 meter amateur bands should continue to provide very interesting possibilities for rare DX QSOs.... 10 and 6 may be open very late in the evening local time, so keep your radios on, and from time to time call CQ, because if every radio amateur just listens, then no one will know that the bands are open...
See you on 28.5 or 50.11 megaHertz.... this whole week looks very promising for adding quite a few interesting QSOs to the logs!
prepared Tuesday, 3-Apr-2001; transmitted Friday, 6-Apr-2001 14:21 EDT
Arnie Coro CO2KK
Havana, Cuba
3 April, 2001Postal address:
Arnie Coro, "Dxers Unlimited"
Radio Havana Cuba, Havana, CUBA
e-mail: arnie@radiohc.org
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